diff --git a/src/api/appservice_server.rs b/src/api/appservice_server.rs
index 276a1c57..98097d22 100644
--- a/src/api/appservice_server.rs
+++ b/src/api/appservice_server.rs
@@ -80,10 +80,11 @@ where
             .expect("http::response::Builder is usable"),
     );
 
+    // TODO: handle timeout
     let body = response.bytes().await.unwrap_or_else(|e| {
         warn!("server error: {}", e);
         Vec::new().into()
-    }); // TODO: handle timeout
+    });
 
     if status != 200 {
         warn!(
diff --git a/src/api/client_server/keys.rs b/src/api/client_server/keys.rs
index 8a9191d1..06c06dcb 100644
--- a/src/api/client_server/keys.rs
+++ b/src/api/client_server/keys.rs
@@ -138,7 +138,8 @@ pub(crate) async fn upload_signing_keys_route(
             master_key,
             &body.self_signing_key,
             &body.user_signing_key,
-            true, // notify so that other users see the new keys
+            // notify so that other users see the new keys
+            true,
         )?;
     }
 
@@ -196,7 +197,8 @@ pub(crate) async fn upload_signatures_route(
     }
 
     Ok(upload_signatures::v3::Response {
-        failures: BTreeMap::new(), // TODO: integrate
+        // TODO: integrate
+        failures: BTreeMap::new(),
     })
 }
 
@@ -252,7 +254,8 @@ pub(crate) async fn get_key_changes_route(
     }
     Ok(get_key_changes::v3::Response {
         changed: device_list_updates.into_iter().collect(),
-        left: Vec::new(), // TODO
+        // TODO
+        left: Vec::new(),
     })
 }
 
@@ -422,7 +425,8 @@ pub(crate) async fn get_keys_helper<F: Fn(&UserId) -> bool>(
                 let raw = serde_json::from_value(json).expect("Raw::from_value always works");
                 services().users.add_cross_signing_keys(
                     &user, &raw, &None, &None,
-                    false, // Dont notify. A notification would trigger another key request resulting in an endless loop
+                    // Dont notify. A notification would trigger another key request resulting in an endless loop
+                    false,
                 )?;
                 master_keys.insert(user, raw);
             }
diff --git a/src/api/client_server/membership.rs b/src/api/client_server/membership.rs
index 005ce01d..be3d59fa 100644
--- a/src/api/client_server/membership.rs
+++ b/src/api/client_server/membership.rs
@@ -49,7 +49,8 @@ pub(crate) async fn join_room_by_id_route(
 ) -> Result<join_room_by_id::v3::Response> {
     let sender_user = body.sender_user.as_ref().expect("user is authenticated");
 
-    let mut servers = Vec::new(); // There is no body.server_name for /roomId/join
+    // There is no body.server_name for /roomId/join
+    let mut servers = Vec::new();
     servers.extend(
         services()
             .rooms
@@ -1012,7 +1013,8 @@ async fn join_room_by_id_helper(
         let authenticated = state_res::event_auth::auth_check(
             &state_res::RoomVersion::new(&room_version_id).expect("room version is supported"),
             &parsed_join_pdu,
-            None::<PduEvent>, // TODO: third party invite
+            // TODO: third party invite
+            None::<PduEvent>,
             |k, s| {
                 services()
                     .rooms
diff --git a/src/api/client_server/room.rs b/src/api/client_server/room.rs
index 1b266e25..b34f04bc 100644
--- a/src/api/client_server/room.rs
+++ b/src/api/client_server/room.rs
@@ -163,7 +163,8 @@ pub(crate) async fn create_room_route(
                         })?,
                     );
                 }
-                RoomVersionId::V11 => {} // V11 removed the "creator" key
+                // V11 removed the "creator" key
+                RoomVersionId::V11 => {}
                 _ => unreachable!("Validity of room version already checked"),
             }
 
@@ -790,7 +791,8 @@ pub(crate) async fn upgrade_room_route(
                 .room_state_get(&body.room_id, &event_type, "")?
             {
                 Some(v) => v.content.clone(),
-                None => continue, // Skipping missing events.
+                // Skipping missing events.
+                None => continue,
             };
 
         services()
diff --git a/src/api/client_server/search.rs b/src/api/client_server/search.rs
index 9d69d3b8..2b6c9f12 100644
--- a/src/api/client_server/search.rs
+++ b/src/api/client_server/search.rs
@@ -74,7 +74,8 @@ pub(crate) async fn search_events_route(
                 "Invalid next_batch token.",
             ))
         }
-        None => 0, // Default to the start
+        // Default to the start
+        None => 0,
     };
 
     let mut results = Vec::new();
@@ -133,10 +134,12 @@ pub(crate) async fn search_events_route(
     Ok(search_events::v3::Response::new(ResultCategories {
         room_events: ResultRoomEvents {
             count: None,
-            groups: BTreeMap::new(), // TODO
+            // TODO
+            groups: BTreeMap::new(),
             next_batch,
             results,
-            state: BTreeMap::new(), // TODO
+            // TODO
+            state: BTreeMap::new(),
             highlights: search_criteria
                 .search_term
                 .split_terminator(|c: char| !c.is_alphanumeric())
diff --git a/src/api/client_server/state.rs b/src/api/client_server/state.rs
index 8ac33241..dda83e10 100644
--- a/src/api/client_server/state.rs
+++ b/src/api/client_server/state.rs
@@ -30,7 +30,8 @@ pub(crate) async fn send_state_event_for_key_route(
         sender_user,
         &body.room_id,
         &body.event_type,
-        &body.body.body, // Yes, I hate it too
+        // Yes, I hate it too
+        &body.body.body,
         body.state_key.clone(),
     )
     .await?;
@@ -210,7 +211,8 @@ async fn send_state_event_for_key_helper(
                     .rooms
                     .alias
                     .resolve_local_alias(&alias)?
-                    .filter(|room| room == room_id) // Make sure it's the right room
+                    // Make sure it's the right room
+                    .filter(|room| room == room_id)
                     .is_none()
             {
                 return Err(Error::BadRequest(
diff --git a/src/api/client_server/sync.rs b/src/api/client_server/sync.rs
index d787769c..9f7a2626 100644
--- a/src/api/client_server/sync.rs
+++ b/src/api/client_server/sync.rs
@@ -209,7 +209,8 @@ async fn sync_helper(
         .unwrap_or(0);
     let sincecount = PduCount::Normal(since);
 
-    let mut left_encrypted_users = HashSet::new(); // Users that have left any encrypted rooms the sender was in
+    // Users that have left any encrypted rooms the sender was in
+    let mut left_encrypted_users = HashSet::new();
     let mut device_list_updates = HashSet::new();
     let mut device_list_left = HashSet::new();
 
@@ -492,7 +493,8 @@ async fn sync_helper(
             leave: left_rooms,
             join: joined_rooms,
             invite: invited_rooms,
-            knock: BTreeMap::new(), // TODO
+            // TODO
+            knock: BTreeMap::new(),
         },
         presence: Presence::default(),
         account_data: GlobalAccountData {
@@ -543,7 +545,8 @@ async fn sync_helper(
         };
         Ok((response, false))
     } else {
-        Ok((response, since != next_batch)) // Only cache if we made progress
+        // Only cache if we made progress
+        Ok((response, since != next_batch))
     }
 }
 
@@ -1201,7 +1204,8 @@ pub(crate) async fn sync_events_v4_route(
             .remove_to_device_events(&sender_user, &sender_device, globalsince)?;
     }
 
-    let mut left_encrypted_users = HashSet::new(); // Users that have left any encrypted rooms the sender was in
+    // Users that have left any encrypted rooms the sender was in
+    let mut left_encrypted_users = HashSet::new();
     let mut device_list_changes = HashSet::new();
     let mut device_list_left = HashSet::new();
 
@@ -1381,7 +1385,8 @@ pub(crate) async fn sync_events_v4_route(
     }
 
     let mut lists = BTreeMap::new();
-    let mut todo_rooms = BTreeMap::new(); // and required state
+    // and required state
+    let mut todo_rooms = BTreeMap::new();
 
     for (list_id, list) in body.lists {
         if list.filters.and_then(|f| f.is_invite).unwrap_or(false) {
@@ -1646,7 +1651,8 @@ pub(crate) async fn sync_events_v4_route(
                         .map(UInt::new_saturating)
                         .unwrap_or(uint!(0)),
                 ),
-                num_live: None, // Count events in timeline greater than global sync counter
+                // Count events in timeline greater than global sync counter
+                num_live: None,
                 timestamp: None,
             },
         );
diff --git a/src/api/ruma_wrapper/axum.rs b/src/api/ruma_wrapper/axum.rs
index 22931cf2..55485023 100644
--- a/src/api/ruma_wrapper/axum.rs
+++ b/src/api/ruma_wrapper/axum.rs
@@ -334,7 +334,8 @@ where
 
 struct XMatrix {
     origin: OwnedServerName,
-    key: String, // KeyName?
+    // KeyName?
+    key: String,
     sig: String,
 }
 
diff --git a/src/api/server_server.rs b/src/api/server_server.rs
index 7b0e9afe..86c34276 100644
--- a/src/api/server_server.rs
+++ b/src/api/server_server.rs
@@ -260,10 +260,11 @@ where
             );
 
             debug!("Getting response bytes from {destination}");
+            // TODO: handle timeout
             let body = response.bytes().await.unwrap_or_else(|e| {
                 warn!("server error {}", e);
                 Vec::new().into()
-            }); // TODO: handle timeout
+            });
             debug!("Got response bytes from {destination}");
 
             if status != 200 {
@@ -1555,7 +1556,8 @@ async fn create_join_event(
             .filter_map(|(_, id)| services().rooms.timeline.get_pdu_json(id).ok().flatten())
             .map(PduEvent::convert_to_outgoing_federation_event)
             .collect(),
-        event: None, // TODO: handle restricted joins
+        // TODO: handle restricted joins
+        event: None,
     })
 }
 
diff --git a/src/config.rs b/src/config.rs
index 2313b92f..0f9a9c9c 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -239,11 +239,13 @@ fn default_pdu_cache_capacity() -> u32 {
 }
 
 fn default_cleanup_second_interval() -> u32 {
-    60 // every minute
+    // every minute
+    60
 }
 
 fn default_max_request_size() -> u32 {
-    20 * 1024 * 1024 // Default to 20 MB
+    // Default to 20 MB
+    20 * 1024 * 1024
 }
 
 fn default_max_concurrent_requests() -> u16 {
diff --git a/src/config/proxy.rs b/src/config/proxy.rs
index 2adab9f6..91ada136 100644
--- a/src/config/proxy.rs
+++ b/src/config/proxy.rs
@@ -45,7 +45,8 @@ impl ProxyConfig {
             ProxyConfig::None => None,
             ProxyConfig::Global { url } => Some(Proxy::all(url)?),
             ProxyConfig::ByDomain(proxies) => Some(Proxy::custom(move |url| {
-                proxies.iter().find_map(|proxy| proxy.for_url(url)).cloned() // first matching proxy
+                // first matching proxy
+                proxies.iter().find_map(|proxy| proxy.for_url(url)).cloned()
             })),
         })
     }
@@ -63,8 +64,10 @@ pub(crate) struct PartialProxyConfig {
 impl PartialProxyConfig {
     pub(crate) fn for_url(&self, url: &Url) -> Option<&Url> {
         let domain = url.domain()?;
-        let mut included_because = None; // most specific reason it was included
-        let mut excluded_because = None; // most specific reason it was excluded
+        // most specific reason it was included
+        let mut included_because = None;
+        // most specific reason it was excluded
+        let mut excluded_because = None;
         if self.include.is_empty() {
             // treat empty include list as `*`
             included_because = Some(&WildCardedDomain::WildCard);
@@ -86,7 +89,8 @@ impl PartialProxyConfig {
             }
         }
         match (included_because, excluded_because) {
-            (Some(a), Some(b)) if a.more_specific_than(b) => Some(&self.url), // included for a more specific reason than excluded
+            // included for a more specific reason than excluded
+            (Some(a), Some(b)) if a.more_specific_than(b) => Some(&self.url),
             (Some(_), None) => Some(&self.url),
             _ => None,
         }
diff --git a/src/database.rs b/src/database.rs
index 94de39c9..ea964a52 100644
--- a/src/database.rs
+++ b/src/database.rs
@@ -42,77 +42,122 @@ pub(crate) struct KeyValueDatabase {
     pub(super) userid_avatarurl: Arc<dyn KvTree>,
     pub(super) userid_blurhash: Arc<dyn KvTree>,
     pub(super) userdeviceid_token: Arc<dyn KvTree>,
-    pub(super) userdeviceid_metadata: Arc<dyn KvTree>, // This is also used to check if a device exists
-    pub(super) userid_devicelistversion: Arc<dyn KvTree>, // DevicelistVersion = u64
+
+    // This is also used to check if a device exists
+    pub(super) userdeviceid_metadata: Arc<dyn KvTree>,
+
+    // DevicelistVersion = u64
+    pub(super) userid_devicelistversion: Arc<dyn KvTree>,
     pub(super) token_userdeviceid: Arc<dyn KvTree>,
 
-    pub(super) onetimekeyid_onetimekeys: Arc<dyn KvTree>, // OneTimeKeyId = UserId + DeviceKeyId
-    pub(super) userid_lastonetimekeyupdate: Arc<dyn KvTree>, // LastOneTimeKeyUpdate = Count
-    pub(super) keychangeid_userid: Arc<dyn KvTree>,       // KeyChangeId = UserId/RoomId + Count
-    pub(super) keyid_key: Arc<dyn KvTree>, // KeyId = UserId + KeyId (depends on key type)
+    // OneTimeKeyId = UserId + DeviceKeyId
+    pub(super) onetimekeyid_onetimekeys: Arc<dyn KvTree>,
+
+    // LastOneTimeKeyUpdate = Count
+    pub(super) userid_lastonetimekeyupdate: Arc<dyn KvTree>,
+
+    // KeyChangeId = UserId/RoomId + Count
+    pub(super) keychangeid_userid: Arc<dyn KvTree>,
+
+    // KeyId = UserId + KeyId (depends on key type)
+    pub(super) keyid_key: Arc<dyn KvTree>,
     pub(super) userid_masterkeyid: Arc<dyn KvTree>,
     pub(super) userid_selfsigningkeyid: Arc<dyn KvTree>,
     pub(super) userid_usersigningkeyid: Arc<dyn KvTree>,
 
-    pub(super) userfilterid_filter: Arc<dyn KvTree>, // UserFilterId = UserId + FilterId
+    // UserFilterId = UserId + FilterId
+    pub(super) userfilterid_filter: Arc<dyn KvTree>,
 
-    pub(super) todeviceid_events: Arc<dyn KvTree>, // ToDeviceId = UserId + DeviceId + Count
+    // ToDeviceId = UserId + DeviceId + Count
+    pub(super) todeviceid_events: Arc<dyn KvTree>,
 
     // Trees "owned" by `self::key_value::uiaa`
-    pub(super) userdevicesessionid_uiaainfo: Arc<dyn KvTree>, // User-interactive authentication
+    // User-interactive authentication
+    pub(super) userdevicesessionid_uiaainfo: Arc<dyn KvTree>,
     pub(super) userdevicesessionid_uiaarequest:
         RwLock<BTreeMap<(OwnedUserId, OwnedDeviceId, String), CanonicalJsonValue>>,
 
     // Trees "owned" by `self::key_value::rooms::edus`
-    pub(super) readreceiptid_readreceipt: Arc<dyn KvTree>, // ReadReceiptId = RoomId + Count + UserId
-    pub(super) roomuserid_privateread: Arc<dyn KvTree>, // RoomUserId = Room + User, PrivateRead = Count
-    pub(super) roomuserid_lastprivatereadupdate: Arc<dyn KvTree>, // LastPrivateReadUpdate = Count
+    // ReadReceiptId = RoomId + Count + UserId
+    pub(super) readreceiptid_readreceipt: Arc<dyn KvTree>,
+
+    // RoomUserId = Room + User, PrivateRead = Count
+    pub(super) roomuserid_privateread: Arc<dyn KvTree>,
+
+    // LastPrivateReadUpdate = Count
+    pub(super) roomuserid_lastprivatereadupdate: Arc<dyn KvTree>,
+
+    // PresenceId = RoomId + Count + UserId
     // This exists in the database already but is currently unused
     #[allow(dead_code)]
-    pub(super) presenceid_presence: Arc<dyn KvTree>, // PresenceId = RoomId + Count + UserId
+    pub(super) presenceid_presence: Arc<dyn KvTree>,
+
+    // LastPresenceUpdate = Count
     // This exists in the database already but is currently unused
     #[allow(dead_code)]
-    pub(super) userid_lastpresenceupdate: Arc<dyn KvTree>, // LastPresenceUpdate = Count
+    pub(super) userid_lastpresenceupdate: Arc<dyn KvTree>,
 
     // Trees "owned" by `self::key_value::rooms`
-    pub(super) pduid_pdu: Arc<dyn KvTree>, // PduId = ShortRoomId + Count
+    // PduId = ShortRoomId + Count
+    pub(super) pduid_pdu: Arc<dyn KvTree>,
     pub(super) eventid_pduid: Arc<dyn KvTree>,
     pub(super) roomid_pduleaves: Arc<dyn KvTree>,
     pub(super) alias_roomid: Arc<dyn KvTree>,
-    pub(super) aliasid_alias: Arc<dyn KvTree>, // AliasId = RoomId + Count
+
+    // AliasId = RoomId + Count
+    pub(super) aliasid_alias: Arc<dyn KvTree>,
     pub(super) publicroomids: Arc<dyn KvTree>,
 
-    pub(super) threadid_userids: Arc<dyn KvTree>, // ThreadId = RoomId + Count
+    // ThreadId = RoomId + Count
+    pub(super) threadid_userids: Arc<dyn KvTree>,
 
-    pub(super) tokenids: Arc<dyn KvTree>, // TokenId = ShortRoomId + Token + PduIdCount
+    // TokenId = ShortRoomId + Token + PduIdCount
+    pub(super) tokenids: Arc<dyn KvTree>,
 
     /// Participating servers in a room.
-    pub(super) roomserverids: Arc<dyn KvTree>, // RoomServerId = RoomId + ServerName
-    pub(super) serverroomids: Arc<dyn KvTree>, // ServerRoomId = ServerName + RoomId
+    // RoomServerId = RoomId + ServerName
+    pub(super) roomserverids: Arc<dyn KvTree>,
+
+    // ServerRoomId = ServerName + RoomId
+    pub(super) serverroomids: Arc<dyn KvTree>,
 
     pub(super) userroomid_joined: Arc<dyn KvTree>,
     pub(super) roomuserid_joined: Arc<dyn KvTree>,
     pub(super) roomid_joinedcount: Arc<dyn KvTree>,
     pub(super) roomid_invitedcount: Arc<dyn KvTree>,
     pub(super) roomuseroncejoinedids: Arc<dyn KvTree>,
-    pub(super) userroomid_invitestate: Arc<dyn KvTree>, // InviteState = Vec<Raw<Pdu>>
-    pub(super) roomuserid_invitecount: Arc<dyn KvTree>, // InviteCount = Count
+
+    // InviteState = Vec<Raw<Pdu>>
+    pub(super) userroomid_invitestate: Arc<dyn KvTree>,
+
+    // InviteCount = Count
+    pub(super) roomuserid_invitecount: Arc<dyn KvTree>,
     pub(super) userroomid_leftstate: Arc<dyn KvTree>,
     pub(super) roomuserid_leftcount: Arc<dyn KvTree>,
 
-    pub(super) disabledroomids: Arc<dyn KvTree>, // Rooms where incoming federation handling is disabled
+    // Rooms where incoming federation handling is disabled
+    pub(super) disabledroomids: Arc<dyn KvTree>,
 
-    pub(super) lazyloadedids: Arc<dyn KvTree>, // LazyLoadedIds = UserId + DeviceId + RoomId + LazyLoadedUserId
+    // LazyLoadedIds = UserId + DeviceId + RoomId + LazyLoadedUserId
+    pub(super) lazyloadedids: Arc<dyn KvTree>,
 
-    pub(super) userroomid_notificationcount: Arc<dyn KvTree>, // NotifyCount = u64
-    pub(super) userroomid_highlightcount: Arc<dyn KvTree>,    // HightlightCount = u64
-    pub(super) roomuserid_lastnotificationread: Arc<dyn KvTree>, // LastNotificationRead = u64
+    // NotifyCount = u64
+    pub(super) userroomid_notificationcount: Arc<dyn KvTree>,
+
+    // HightlightCount = u64
+    pub(super) userroomid_highlightcount: Arc<dyn KvTree>,
+
+    // LastNotificationRead = u64
+    pub(super) roomuserid_lastnotificationread: Arc<dyn KvTree>,
 
     /// Remember the current state hash of a room.
     pub(super) roomid_shortstatehash: Arc<dyn KvTree>,
+
     pub(super) roomsynctoken_shortstatehash: Arc<dyn KvTree>,
+
     /// Remember the state hash at events in the past.
     pub(super) shorteventid_shortstatehash: Arc<dyn KvTree>,
+
     /// StateKey = EventType + StateKey, ShortStateKey = Count
     pub(super) statekey_shortstatekey: Arc<dyn KvTree>,
     pub(super) shortstatekey_statekey: Arc<dyn KvTree>,
@@ -123,7 +168,9 @@ pub(crate) struct KeyValueDatabase {
     pub(super) eventid_shorteventid: Arc<dyn KvTree>,
 
     pub(super) statehash_shortstatehash: Arc<dyn KvTree>,
-    pub(super) shortstatehash_statediff: Arc<dyn KvTree>, // StateDiff = parent (or 0) + (shortstatekey+shorteventid++) + 0_u64 + (shortstatekey+shorteventid--)
+
+    // StateDiff = parent (or 0) + (shortstatekey+shorteventid++) + 0_u64 + (shortstatekey+shorteventid--)
+    pub(super) shortstatehash_statediff: Arc<dyn KvTree>,
 
     pub(super) shorteventid_authchain: Arc<dyn KvTree>,
 
@@ -134,26 +181,44 @@ pub(crate) struct KeyValueDatabase {
 
     /// ShortEventId + ShortEventId -> ().
     pub(super) tofrom_relation: Arc<dyn KvTree>,
+
     /// RoomId + EventId -> Parent PDU EventId.
     pub(super) referencedevents: Arc<dyn KvTree>,
 
     // Trees "owned" by `self::key_value::account_data`
-    pub(super) roomuserdataid_accountdata: Arc<dyn KvTree>, // RoomUserDataId = Room + User + Count + Type
-    pub(super) roomusertype_roomuserdataid: Arc<dyn KvTree>, // RoomUserType = Room + User + Type
+    // RoomUserDataId = Room + User + Count + Type
+    pub(super) roomuserdataid_accountdata: Arc<dyn KvTree>,
+
+    // RoomUserType = Room + User + Type
+    pub(super) roomusertype_roomuserdataid: Arc<dyn KvTree>,
 
     // Trees "owned" by `self::key_value::media`
-    pub(super) mediaid_file: Arc<dyn KvTree>, // MediaId = MXC + WidthHeight + ContentDisposition + ContentType
+    // MediaId = MXC + WidthHeight + ContentDisposition + ContentType
+    pub(super) mediaid_file: Arc<dyn KvTree>,
+
     // Trees "owned" by `self::key_value::key_backups`
-    pub(super) backupid_algorithm: Arc<dyn KvTree>, // BackupId = UserId + Version(Count)
-    pub(super) backupid_etag: Arc<dyn KvTree>,      // BackupId = UserId + Version(Count)
-    pub(super) backupkeyid_backup: Arc<dyn KvTree>, // BackupKeyId = UserId + Version + RoomId + SessionId
+    // BackupId = UserId + Version(Count)
+    pub(super) backupid_algorithm: Arc<dyn KvTree>,
+
+    // BackupId = UserId + Version(Count)
+    pub(super) backupid_etag: Arc<dyn KvTree>,
+
+    // BackupKeyId = UserId + Version + RoomId + SessionId
+    pub(super) backupkeyid_backup: Arc<dyn KvTree>,
 
     // Trees "owned" by `self::key_value::transaction_ids`
-    pub(super) userdevicetxnid_response: Arc<dyn KvTree>, // Response can be empty (/sendToDevice) or the event id (/send)
+    // Response can be empty (/sendToDevice) or the event id (/send)
+    pub(super) userdevicetxnid_response: Arc<dyn KvTree>,
+
     // Trees "owned" by `self::key_value::sending`
-    pub(super) servername_educount: Arc<dyn KvTree>, // EduCount: Count of last EDU sync
-    pub(super) servernameevent_data: Arc<dyn KvTree>, // ServernameEvent = (+ / $)SenderKey / ServerName / UserId + PduId / Id (for edus), Data = EDU content
-    pub(super) servercurrentevent_data: Arc<dyn KvTree>, // ServerCurrentEvents = (+ / $)ServerName / UserId + PduId / Id (for edus), Data = EDU content
+    // EduCount: Count of last EDU sync
+    pub(super) servername_educount: Arc<dyn KvTree>,
+
+    // ServernameEvent = (+ / $)SenderKey / ServerName / UserId + PduId / Id (for edus), Data = EDU content
+    pub(super) servernameevent_data: Arc<dyn KvTree>,
+
+    // ServerCurrentEvents = (+ / $)ServerName / UserId + PduId / Id (for edus), Data = EDU content
+    pub(super) servercurrentevent_data: Arc<dyn KvTree>,
 
     // Trees "owned" by `self::key_value::appservice`
     pub(super) id_appserviceregistrations: Arc<dyn KvTree>,
@@ -278,7 +343,8 @@ impl KeyValueDatabase {
             userdevicesessionid_uiaainfo: builder.open_tree("userdevicesessionid_uiaainfo")?,
             userdevicesessionid_uiaarequest: RwLock::new(BTreeMap::new()),
             readreceiptid_readreceipt: builder.open_tree("readreceiptid_readreceipt")?,
-            roomuserid_privateread: builder.open_tree("roomuserid_privateread")?, // "Private" read receipt
+            // "Private" read receipt
+            roomuserid_privateread: builder.open_tree("roomuserid_privateread")?,
             roomuserid_lastprivatereadupdate: builder
                 .open_tree("roomuserid_lastprivatereadupdate")?,
             presenceid_presence: builder.open_tree("presenceid_presence")?,
@@ -601,7 +667,8 @@ impl KeyValueDatabase {
                             current_sstatehash,
                             Arc::new(statediffnew),
                             Arc::new(statediffremoved),
-                            2, // every state change is 2 event changes on average
+                            // every state change is 2 event changes on average
+                            2,
                             states_parents,
                         )?;
 
diff --git a/src/database/abstraction/sqlite.rs b/src/database/abstraction/sqlite.rs
index 7609698a..1dc8a47d 100644
--- a/src/database/abstraction/sqlite.rs
+++ b/src/database/abstraction/sqlite.rs
@@ -275,7 +275,8 @@ impl KvTree for SqliteTable {
         backwards: bool,
     ) -> Box<dyn Iterator<Item = TupleOfBytes> + 'a> {
         let guard = self.engine.read_lock_iterator();
-        let from = from.to_vec(); // TODO change interface?
+        // TODO change interface?
+        let from = from.to_vec();
 
         if backwards {
             let statement = Box::leak(Box::new(
diff --git a/src/database/key_value/rooms/edus/read_receipt.rs b/src/database/key_value/rooms/edus/read_receipt.rs
index 87c4e6f0..5b5b54aa 100644
--- a/src/database/key_value/rooms/edus/read_receipt.rs
+++ b/src/database/key_value/rooms/edus/read_receipt.rs
@@ -68,7 +68,8 @@ impl service::rooms::edus::read_receipt::Data for KeyValueDatabase {
         let prefix2 = prefix.clone();
 
         let mut first_possible_edu = prefix.clone();
-        first_possible_edu.extend_from_slice(&(since + 1).to_be_bytes()); // +1 so we don't send the event at since
+        // +1 so we don't send the event at since
+        first_possible_edu.extend_from_slice(&(since + 1).to_be_bytes());
 
         Box::new(
             self.readreceiptid_readreceipt
diff --git a/src/database/key_value/rooms/search.rs b/src/database/key_value/rooms/search.rs
index 0154d1a1..a2eba329 100644
--- a/src/database/key_value/rooms/search.rs
+++ b/src/database/key_value/rooms/search.rs
@@ -14,7 +14,8 @@ impl service::rooms::search::Data for KeyValueDatabase {
                 let mut key = shortroomid.to_be_bytes().to_vec();
                 key.extend_from_slice(word.as_bytes());
                 key.push(0xff);
-                key.extend_from_slice(pdu_id); // TODO: currently we save the room id a second time here
+                // TODO: currently we save the room id a second time here
+                key.extend_from_slice(pdu_id);
                 (key, Vec::new())
             });
 
@@ -52,7 +53,8 @@ impl service::rooms::search::Data for KeyValueDatabase {
             last_possible_id.extend_from_slice(&u64::MAX.to_be_bytes());
 
             self.tokenids
-                .iter_from(&last_possible_id, true) // Newest pdus first
+                // Newest pdus first
+                .iter_from(&last_possible_id, true)
                 .take_while(move |(k, _)| k.starts_with(&prefix2))
                 .map(move |(key, _)| key[prefix3.len()..].to_vec())
         });
diff --git a/src/database/key_value/rooms/state.rs b/src/database/key_value/rooms/state.rs
index fd0c81e6..c7e042d2 100644
--- a/src/database/key_value/rooms/state.rs
+++ b/src/database/key_value/rooms/state.rs
@@ -21,7 +21,8 @@ impl service::rooms::state::Data for KeyValueDatabase {
         &self,
         room_id: &RoomId,
         new_shortstatehash: u64,
-        _mutex_lock: &MutexGuard<'_, ()>, // Take mutex guard to make sure users get the room state mutex
+        // Take mutex guard to make sure users get the room state mutex
+        _mutex_lock: &MutexGuard<'_, ()>,
     ) -> Result<()> {
         self.roomid_shortstatehash
             .insert(room_id.as_bytes(), &new_shortstatehash.to_be_bytes())?;
@@ -53,7 +54,8 @@ impl service::rooms::state::Data for KeyValueDatabase {
         &self,
         room_id: &RoomId,
         event_ids: Vec<OwnedEventId>,
-        _mutex_lock: &MutexGuard<'_, ()>, // Take mutex guard to make sure users get the room state mutex
+        // Take mutex guard to make sure users get the room state mutex
+        _mutex_lock: &MutexGuard<'_, ()>,
     ) -> Result<()> {
         let mut prefix = room_id.as_bytes().to_vec();
         prefix.push(0xff);
diff --git a/src/database/key_value/rooms/state_cache.rs b/src/database/key_value/rooms/state_cache.rs
index be085b5c..a1a5025a 100644
--- a/src/database/key_value/rooms/state_cache.rs
+++ b/src/database/key_value/rooms/state_cache.rs
@@ -79,10 +79,11 @@ impl service::rooms::state_cache::Data for KeyValueDatabase {
         userroom_id.push(0xff);
         userroom_id.extend_from_slice(room_id.as_bytes());
 
+        // TODO
         self.userroomid_leftstate.insert(
             &userroom_id,
             &serde_json::to_vec(&Vec::<Raw<AnySyncStateEvent>>::new()).unwrap(),
-        )?; // TODO
+        )?;
         self.roomuserid_leftcount.insert(
             &roomuser_id,
             &services().globals.next_count()?.to_be_bytes(),
diff --git a/src/database/key_value/rooms/user.rs b/src/database/key_value/rooms/user.rs
index 6d5977dd..f3564272 100644
--- a/src/database/key_value/rooms/user.rs
+++ b/src/database/key_value/rooms/user.rs
@@ -123,7 +123,8 @@ impl service::rooms::user::Data for KeyValueDatabase {
                         .find(|(_, &b)| b == 0xff)
                         .ok_or_else(|| Error::bad_database("Invalid userroomid_joined in db."))?
                         .0
-                        + 1; // +1 because the room id starts AFTER the separator
+                        // +1 because the room id starts AFTER the separator
+                        + 1;
 
                     let room_id = key[roomid_index..].to_vec();
 
diff --git a/src/database/key_value/users.rs b/src/database/key_value/users.rs
index 0122d936..d437803f 100644
--- a/src/database/key_value/users.rs
+++ b/src/database/key_value/users.rs
@@ -215,7 +215,8 @@ impl service::users::Data for KeyValueDatabase {
             &serde_json::to_vec(&Device {
                 device_id: device_id.into(),
                 display_name: initial_device_display_name,
-                last_seen_ip: None, // TODO
+                // TODO
+                last_seen_ip: None,
                 last_seen_ts: Some(MilliSecondsSinceUnixEpoch::now()),
             })
             .expect("Device::to_string never fails."),
@@ -365,7 +366,8 @@ impl service::users::Data for KeyValueDatabase {
         prefix.push(0xff);
         prefix.extend_from_slice(device_id.as_bytes());
         prefix.push(0xff);
-        prefix.push(b'"'); // Annoying quotation mark
+        // Annoying quotation mark
+        prefix.push(b'"');
         prefix.extend_from_slice(key_algorithm.as_ref().as_bytes());
         prefix.push(b':');
 
@@ -828,7 +830,8 @@ impl service::users::Data for KeyValueDatabase {
 
         for (key, _) in self
             .todeviceid_events
-            .iter_from(&last, true) // this includes last
+            // this includes last
+            .iter_from(&last, true)
             .take_while(move |(k, _)| k.starts_with(&prefix))
             .map(|(key, _)| {
                 Ok::<_, Error>((
diff --git a/src/service/globals.rs b/src/service/globals.rs
index 98b543c8..a72a5e06 100644
--- a/src/service/globals.rs
+++ b/src/service/globals.rs
@@ -43,16 +43,20 @@ use base64::{engine::general_purpose, Engine as _};
 
 type WellKnownMap = HashMap<OwnedServerName, (FedDest, String)>;
 type TlsNameMap = HashMap<String, (Vec<IpAddr>, u16)>;
-type RateLimitState = (Instant, u32); // Time if last failed try, number of failed tries
+// Time if last failed try, number of failed tries
+type RateLimitState = (Instant, u32);
 type SyncHandle = (
-    Option<String>,                                      // since
-    Receiver<Option<Result<sync_events::v3::Response>>>, // rx
+    // since
+    Option<String>,
+    // rx
+    Receiver<Option<Result<sync_events::v3::Response>>>,
 );
 
 pub(crate) struct Service {
     pub(crate) db: &'static dyn Data,
 
-    pub(crate) actual_destination_cache: Arc<RwLock<WellKnownMap>>, // actual_destination, host
+    // actual_destination, host
+    pub(crate) actual_destination_cache: Arc<RwLock<WellKnownMap>>,
     pub(crate) tls_name_override: Arc<StdRwLock<TlsNameMap>>,
     pub(crate) config: Config,
     keypair: Arc<ruma::signatures::Ed25519KeyPair>,
@@ -69,7 +73,9 @@ pub(crate) struct Service {
     pub(crate) sync_receivers: RwLock<HashMap<(OwnedUserId, OwnedDeviceId), SyncHandle>>,
     pub(crate) roomid_mutex_insert: RwLock<HashMap<OwnedRoomId, Arc<Mutex<()>>>>,
     pub(crate) roomid_mutex_state: RwLock<HashMap<OwnedRoomId, Arc<Mutex<()>>>>,
-    pub(crate) roomid_mutex_federation: RwLock<HashMap<OwnedRoomId, Arc<Mutex<()>>>>, // this lock will be held longer
+
+    // this lock will be held longer
+    pub(crate) roomid_mutex_federation: RwLock<HashMap<OwnedRoomId, Arc<Mutex<()>>>>,
     pub(crate) roomid_federationhandletime: RwLock<HashMap<OwnedRoomId, (OwnedEventId, Instant)>>,
     pub(crate) stateres_mutex: Arc<Mutex<()>>,
     pub(crate) rotate: RotationHandler,
diff --git a/src/service/media.rs b/src/service/media.rs
index 7b12ab1f..76184374 100644
--- a/src/service/media.rs
+++ b/src/service/media.rs
@@ -113,8 +113,9 @@ impl Service {
         width: u32,
         height: u32,
     ) -> Result<Option<FileMeta>> {
+        // 0, 0 because that's the original file
         let (width, height, crop) =
-            Self::thumbnail_properties(width, height).unwrap_or((0, 0, false)); // 0, 0 because that's the original file
+            Self::thumbnail_properties(width, height).unwrap_or((0, 0, false));
 
         if let Ok((content_disposition, content_type, key)) =
             self.db.search_file_metadata(mxc.clone(), width, height)
diff --git a/src/service/pusher.rs b/src/service/pusher.rs
index 6e0fc755..90a3b90d 100644
--- a/src/service/pusher.rs
+++ b/src/service/pusher.rs
@@ -93,10 +93,11 @@ impl Service {
                         .expect("http::response::Builder is usable"),
                 );
 
+                // TODO: handle timeout
                 let body = response.bytes().await.unwrap_or_else(|e| {
                     warn!("server error {}", e);
                     Vec::new().into()
-                }); // TODO: handle timeout
+                });
 
                 if status != 200 {
                     info!(
@@ -201,7 +202,8 @@ impl Service {
 
         let ctx = PushConditionRoomCtx {
             room_id: room_id.to_owned(),
-            member_count: 10_u32.into(), // TODO: get member count efficiently
+            // TODO: get member count efficiently
+            member_count: 10_u32.into(),
             user_id: user.to_owned(),
             user_display_name: services()
                 .users
diff --git a/src/service/rooms/edus/typing.rs b/src/service/rooms/edus/typing.rs
index 44d3e6af..972db4a1 100644
--- a/src/service/rooms/edus/typing.rs
+++ b/src/service/rooms/edus/typing.rs
@@ -6,8 +6,10 @@ use tracing::trace;
 use crate::{services, utils, Result};
 
 pub(crate) struct Service {
-    pub(crate) typing: RwLock<BTreeMap<OwnedRoomId, BTreeMap<OwnedUserId, u64>>>, // u64 is unix timestamp of timeout
-    pub(crate) last_typing_update: RwLock<BTreeMap<OwnedRoomId, u64>>, // timestamp of the last change to typing users
+    // u64 is unix timestamp of timeout
+    pub(crate) typing: RwLock<BTreeMap<OwnedRoomId, BTreeMap<OwnedUserId, u64>>>,
+    // timestamp of the last change to typing users
+    pub(crate) last_typing_update: RwLock<BTreeMap<OwnedRoomId, u64>>,
     pub(crate) typing_update_sender: broadcast::Sender<OwnedRoomId>,
 }
 
diff --git a/src/service/rooms/event_handler.rs b/src/service/rooms/event_handler.rs
index c334f6d8..8ff88088 100644
--- a/src/service/rooms/event_handler.rs
+++ b/src/service/rooms/event_handler.rs
@@ -446,7 +446,8 @@ impl Service {
             if !state_res::event_auth::auth_check(
                 &room_version,
                 &incoming_pdu,
-                None::<PduEvent>, // TODO: third party invite
+                // TODO: third party invite
+                None::<PduEvent>,
                 |k, s| auth_events.get(&(k.to_string().into(), s.to_owned())),
             )
             .map_err(|_e| Error::BadRequest(ErrorKind::InvalidParam, "Auth check failed"))?
@@ -748,7 +749,8 @@ impl Service {
         let check_result = state_res::event_auth::auth_check(
             &room_version,
             &incoming_pdu,
-            None::<PduEvent>, // TODO: third party invite
+            // TODO: third party invite
+            None::<PduEvent>,
             |k, s| {
                 services()
                     .rooms
diff --git a/src/service/rooms/pdu_metadata.rs b/src/service/rooms/pdu_metadata.rs
index 61128e5e..636a3a58 100644
--- a/src/service/rooms/pdu_metadata.rs
+++ b/src/service/rooms/pdu_metadata.rs
@@ -64,7 +64,8 @@ impl Service {
                 let events_after: Vec<_> = services()
                     .rooms
                     .pdu_metadata
-                    .relations_until(sender_user, room_id, target, from)? // TODO: should be relations_after
+                    // TODO: should be relations_after
+                    .relations_until(sender_user, room_id, target, from)?
                     .filter(|r| {
                         r.as_ref().map_or(true, |(_, pdu)| {
                             filter_event_type.as_ref().map_or(true, |t| &&pdu.kind == t)
@@ -90,14 +91,16 @@ impl Service {
                             .user_can_see_event(sender_user, room_id, &pdu.event_id)
                             .unwrap_or(false)
                     })
-                    .take_while(|&(k, _)| Some(k) != to) // Stop at `to`
+                    // Stop at `to`
+                    .take_while(|&(k, _)| Some(k) != to)
                     .collect();
 
                 next_token = events_after.last().map(|(count, _)| count).copied();
 
                 let events_after: Vec<_> = events_after
                     .into_iter()
-                    .rev() // relations are always most recent first
+                    // relations are always most recent first
+                    .rev()
                     .map(|(_, pdu)| pdu.to_message_like_event())
                     .collect();
 
@@ -137,7 +140,8 @@ impl Service {
                             .user_can_see_event(sender_user, room_id, &pdu.event_id)
                             .unwrap_or(false)
                     })
-                    .take_while(|&(k, _)| Some(k) != to) // Stop at `to`
+                    // Stop at `to`
+                    .take_while(|&(k, _)| Some(k) != to)
                     .collect();
 
                 next_token = events_before.last().map(|(count, _)| count).copied();
@@ -167,7 +171,8 @@ impl Service {
         let target = match services().rooms.timeline.get_pdu_count(target)? {
             Some(PduCount::Normal(c)) => c,
             // TODO: Support backfilled relations
-            _ => 0, // This will result in an empty iterator
+            // This will result in an empty iterator
+            _ => 0,
         };
         self.db.relations_until(user_id, room_id, target, until)
     }
diff --git a/src/service/rooms/state.rs b/src/service/rooms/state.rs
index daa17a58..0d4f91a0 100644
--- a/src/service/rooms/state.rs
+++ b/src/service/rooms/state.rs
@@ -35,7 +35,8 @@ impl Service {
         shortstatehash: u64,
         statediffnew: Arc<HashSet<CompressedStateEvent>>,
         _statediffremoved: Arc<HashSet<CompressedStateEvent>>,
-        state_lock: &MutexGuard<'_, ()>, // Take mutex guard to make sure users get the room state mutex
+        // Take mutex guard to make sure users get the room state mutex
+        state_lock: &MutexGuard<'_, ()>,
     ) -> Result<()> {
         for event_id in statediffnew.iter().filter_map(|new| {
             services()
@@ -169,7 +170,8 @@ impl Service {
                 shortstatehash,
                 statediffnew,
                 statediffremoved,
-                1_000_000, // high number because no state will be based on this one
+                // high number because no state will be based on this one
+                1_000_000,
                 states_parents,
             )?;
         }
@@ -315,7 +317,8 @@ impl Service {
         &self,
         room_id: &RoomId,
         shortstatehash: u64,
-        mutex_lock: &MutexGuard<'_, ()>, // Take mutex guard to make sure users get the room state mutex
+        // Take mutex guard to make sure users get the room state mutex
+        mutex_lock: &MutexGuard<'_, ()>,
     ) -> Result<()> {
         self.db.set_room_state(room_id, shortstatehash, mutex_lock)
     }
@@ -358,7 +361,8 @@ impl Service {
         &self,
         room_id: &RoomId,
         event_ids: Vec<OwnedEventId>,
-        state_lock: &MutexGuard<'_, ()>, // Take mutex guard to make sure users get the room state mutex
+        // Take mutex guard to make sure users get the room state mutex
+        state_lock: &MutexGuard<'_, ()>,
     ) -> Result<()> {
         self.db
             .set_forward_extremities(room_id, event_ids, state_lock)
diff --git a/src/service/rooms/state/data.rs b/src/service/rooms/state/data.rs
index 1074a5dd..8e267760 100644
--- a/src/service/rooms/state/data.rs
+++ b/src/service/rooms/state/data.rs
@@ -12,7 +12,8 @@ pub(crate) trait Data: Send + Sync {
         &self,
         room_id: &RoomId,
         new_shortstatehash: u64,
-        _mutex_lock: &MutexGuard<'_, ()>, // Take mutex guard to make sure users get the room state mutex
+        // Take mutex guard to make sure users get the room state mutex
+        _mutex_lock: &MutexGuard<'_, ()>,
     ) -> Result<()>;
 
     /// Associates a state with an event.
@@ -26,6 +27,7 @@ pub(crate) trait Data: Send + Sync {
         &self,
         room_id: &RoomId,
         event_ids: Vec<OwnedEventId>,
-        _mutex_lock: &MutexGuard<'_, ()>, // Take mutex guard to make sure users get the room state mutex
+        // Take mutex guard to make sure users get the room state mutex
+        _mutex_lock: &MutexGuard<'_, ()>,
     ) -> Result<()>;
 }
diff --git a/src/service/rooms/state_cache.rs b/src/service/rooms/state_cache.rs
index 78aba47b..9b15cd88 100644
--- a/src/service/rooms/state_cache.rs
+++ b/src/service/rooms/state_cache.rs
@@ -151,8 +151,10 @@ impl Service {
                 let is_ignored = services()
                     .account_data
                     .get(
-                        None,    // Ignored users are in global account data
-                        user_id, // Receiver
+                        // Ignored users are in global account data
+                        None,
+                        // Receiver
+                        user_id,
                         GlobalAccountDataEventType::IgnoredUserList
                             .to_string()
                             .into(),
diff --git a/src/service/rooms/state_compressor.rs b/src/service/rooms/state_compressor.rs
index 4f91d2e4..13f0912a 100644
--- a/src/service/rooms/state_compressor.rs
+++ b/src/service/rooms/state_compressor.rs
@@ -21,10 +21,14 @@ pub(crate) struct Service {
         LruCache<
             u64,
             Vec<(
-                u64,                                // shortstatehash
-                Arc<HashSet<CompressedStateEvent>>, // full state
-                Arc<HashSet<CompressedStateEvent>>, // added
-                Arc<HashSet<CompressedStateEvent>>, // removed
+                // shortstatehash
+                u64,
+                // full state
+                Arc<HashSet<CompressedStateEvent>>,
+                // added
+                Arc<HashSet<CompressedStateEvent>>,
+                // removed
+                Arc<HashSet<CompressedStateEvent>>,
             )>,
         >,
     >,
@@ -41,10 +45,14 @@ impl Service {
         shortstatehash: u64,
     ) -> Result<
         Vec<(
-            u64,                                // shortstatehash
-            Arc<HashSet<CompressedStateEvent>>, // full state
-            Arc<HashSet<CompressedStateEvent>>, // added
-            Arc<HashSet<CompressedStateEvent>>, // removed
+            // shortstatehash
+            u64,
+            // full state
+            Arc<HashSet<CompressedStateEvent>>,
+            // added
+            Arc<HashSet<CompressedStateEvent>>,
+            // removed
+            Arc<HashSet<CompressedStateEvent>>,
         )>,
     > {
         if let Some(r) = self
@@ -152,10 +160,14 @@ impl Service {
         statediffremoved: Arc<HashSet<CompressedStateEvent>>,
         diff_to_sibling: usize,
         mut parent_states: Vec<(
-            u64,                                // shortstatehash
-            Arc<HashSet<CompressedStateEvent>>, // full state
-            Arc<HashSet<CompressedStateEvent>>, // added
-            Arc<HashSet<CompressedStateEvent>>, // removed
+            // shortstatehash
+            u64,
+            // full state
+            Arc<HashSet<CompressedStateEvent>>,
+            // added
+            Arc<HashSet<CompressedStateEvent>>,
+            // removed
+            Arc<HashSet<CompressedStateEvent>>,
         )>,
     ) -> Result<()> {
         let diffsum = statediffnew.len() + statediffremoved.len();
@@ -318,7 +330,8 @@ impl Service {
                 new_shortstatehash,
                 statediffnew.clone(),
                 statediffremoved.clone(),
-                2, // every state change is 2 event changes on average
+                // every state change is 2 event changes on average
+                2,
                 states_parents,
             )?;
         };
diff --git a/src/service/rooms/timeline.rs b/src/service/rooms/timeline.rs
index eb7db36f..42b802bc 100644
--- a/src/service/rooms/timeline.rs
+++ b/src/service/rooms/timeline.rs
@@ -177,7 +177,8 @@ impl Service {
         pdu: &PduEvent,
         mut pdu_json: CanonicalJsonObject,
         leaves: Vec<OwnedEventId>,
-        state_lock: &MutexGuard<'_, ()>, // Take mutex guard to make sure users get the room state mutex
+        // Take mutex guard to make sure users get the room state mutex
+        state_lock: &MutexGuard<'_, ()>,
     ) -> Result<Vec<u8>> {
         let shortroomid = services()
             .rooms
@@ -527,7 +528,8 @@ impl Service {
                         .threads
                         .add_to_thread(&thread.event_id, pdu)?;
                 }
-                _ => {} // TODO: Aggregate other types
+                // TODO: Aggregate other types
+                _ => {}
             }
         }
 
@@ -598,7 +600,8 @@ impl Service {
         pdu_builder: PduBuilder,
         sender: &UserId,
         room_id: &RoomId,
-        _mutex_lock: &MutexGuard<'_, ()>, // Take mutex guard to make sure users get the room state mutex
+        // Take mutex guard to make sure users get the room state mutex
+        _mutex_lock: &MutexGuard<'_, ()>,
     ) -> Result<(PduEvent, CanonicalJsonObject)> {
         let PduBuilder {
             event_type,
@@ -702,7 +705,8 @@ impl Service {
         let auth_check = state_res::auth_check(
             &room_version,
             &pdu,
-            None::<PduEvent>, // TODO: third_party_invite
+            // TODO: third_party_invite
+            None::<PduEvent>,
             |k, s| auth_events.get(&(k.clone(), s.to_owned())),
         )
         .map_err(|e| {
@@ -781,7 +785,8 @@ impl Service {
         pdu_builder: PduBuilder,
         sender: &UserId,
         room_id: &RoomId,
-        state_lock: &MutexGuard<'_, ()>, // Take mutex guard to make sure users get the room state mutex
+        // Take mutex guard to make sure users get the room state mutex
+        state_lock: &MutexGuard<'_, ()>,
     ) -> Result<Arc<EventId>> {
         let (pdu, pdu_json) =
             self.create_hash_and_sign_event(pdu_builder, sender, room_id, state_lock)?;
@@ -990,7 +995,8 @@ impl Service {
         new_room_leaves: Vec<OwnedEventId>,
         state_ids_compressed: Arc<HashSet<CompressedStateEvent>>,
         soft_fail: bool,
-        state_lock: &MutexGuard<'_, ()>, // Take mutex guard to make sure users get the room state mutex
+        // Take mutex guard to make sure users get the room state mutex
+        state_lock: &MutexGuard<'_, ()>,
     ) -> Result<Option<Vec<u8>>> {
         // We append to state before appending the pdu, so we don't have a moment in time with the
         // pdu without it's state. This is okay because append_pdu can't fail.
diff --git a/src/service/sending.rs b/src/service/sending.rs
index 9cfb8cfe..ebfaf379 100644
--- a/src/service/sending.rs
+++ b/src/service/sending.rs
@@ -47,7 +47,8 @@ use tracing::{debug, error, warn};
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub(crate) enum OutgoingKind {
     Appservice(String),
-    Push(OwnedUserId, String), // user and pushkey
+    // user and pushkey
+    Push(OwnedUserId, String),
     Normal(OwnedServerName),
 }
 
@@ -81,8 +82,10 @@ impl OutgoingKind {
 
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub(crate) enum SendingEventType {
-    Pdu(Vec<u8>), // pduid
-    Edu(Vec<u8>), // pdu json
+    // pduid
+    Pdu(Vec<u8>),
+    // pdu json
+    Edu(Vec<u8>),
 }
 
 pub(crate) struct Service {
@@ -96,8 +99,10 @@ pub(crate) struct Service {
 
 enum TransactionStatus {
     Running,
-    Failed(u32, Instant), // number of times failed, time of last failure
-    Retrying(u32),        // number of times failed
+    // number of times failed, time of last failure
+    Failed(u32, Instant),
+    // number of times failed
+    Retrying(u32),
 }
 
 impl Service {
@@ -203,7 +208,8 @@ impl Service {
     fn select_events(
         &self,
         outgoing_kind: &OutgoingKind,
-        new_events: Vec<(SendingEventType, Vec<u8>)>, // Events we want to send: event and full key
+        // Events we want to send: event and full key
+        new_events: Vec<(SendingEventType, Vec<u8>)>,
         current_transaction_status: &mut HashMap<OutgoingKind, TransactionStatus>,
     ) -> Result<Option<Vec<SendingEventType>>> {
         let mut retry = false;
@@ -214,7 +220,8 @@ impl Service {
         entry
             .and_modify(|e| match e {
                 TransactionStatus::Running | TransactionStatus::Retrying(_) => {
-                    allow = false; // already running
+                    // already running
+                    allow = false;
                 }
                 TransactionStatus::Failed(tries, time) => {
                     // Fail if a request has failed recently (exponential backoff)
@@ -444,7 +451,6 @@ impl Service {
 
     /// Cleanup event data
     /// Used for instance after we remove an appservice registration
-    ///
     #[tracing::instrument(skip(self))]
     pub(crate) fn cleanup_events(&self, appservice_id: String) -> Result<()> {
         self.db
@@ -543,9 +549,8 @@ impl Service {
                                     })?,
                             );
                         }
-                        SendingEventType::Edu(_) => {
-                            // Push gateways don't need EDUs (?)
-                        }
+                        // Push gateways don't need EDUs (?)
+                        SendingEventType::Edu(_) => {}
                     }
                 }
 
diff --git a/src/service/uiaa.rs b/src/service/uiaa.rs
index 1efd1d85..1cb026d9 100644
--- a/src/service/uiaa.rs
+++ b/src/service/uiaa.rs
@@ -29,7 +29,8 @@ impl Service {
         self.db.set_uiaa_request(
             user_id,
             device_id,
-            uiaainfo.session.as_ref().expect("session should be set"), // TODO: better session error handling (why is it optional in ruma?)
+            // TODO: better session error handling (why is it optional in ruma?)
+            uiaainfo.session.as_ref().expect("session should be set"),
             json_body,
         )?;
         self.db.update_uiaa_session(
diff --git a/src/service/users.rs b/src/service/users.rs
index 53882040..b69c98b0 100644
--- a/src/service/users.rs
+++ b/src/service/users.rs
@@ -28,7 +28,8 @@ use crate::{services, Error, Result};
 pub(crate) struct SlidingSyncCache {
     lists: BTreeMap<String, SyncRequestList>,
     subscriptions: BTreeMap<OwnedRoomId, sync_events::v4::RoomSubscription>,
-    known_rooms: BTreeMap<String, BTreeMap<OwnedRoomId, u64>>, // For every room, the roomsince number
+    // For every room, the roomsince number
+    known_rooms: BTreeMap<String, BTreeMap<OwnedRoomId, u64>>,
     extensions: ExtensionsConfig,
 }
 
diff --git a/src/utils.rs b/src/utils.rs
index a335e29c..194f0eef 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -27,7 +27,8 @@ pub(crate) fn increment(old: Option<&[u8]>) -> Vec<u8> {
             let number = u64::from_be_bytes(bytes);
             number + 1
         }
-        _ => 1, // Start at one. since 0 should return the first event in the db
+        // Start at one. since 0 should return the first event in the db
+        _ => 1,
     };
 
     number.to_be_bytes().to_vec()
@@ -97,10 +98,12 @@ where
         other_iterators.iter_mut().all(|it| {
             while let Some(element) = it.peek() {
                 match check_order(element, target) {
-                    Ordering::Greater => return false, // We went too far
-                    Ordering::Equal => return true,    // Element is in both iters
+                    // We went too far
+                    Ordering::Greater => return false,
+                    // Element is in both iters
+                    Ordering::Equal => return true,
+                    // Keep searching
                     Ordering::Less => {
-                        // Keep searching
                         it.next();
                     }
                 }
diff --git a/src/utils/error.rs b/src/utils/error.rs
index ae8a7aff..c0655de5 100644
--- a/src/utils/error.rs
+++ b/src/utils/error.rs
@@ -63,8 +63,9 @@ pub(crate) enum Error {
     Uiaa(UiaaInfo),
     #[error("{0}: {1}")]
     BadRequest(ErrorKind, &'static str),
+    // This is only needed for when a room alias already exists
     #[error("{0}")]
-    Conflict(&'static str), // This is only needed for when a room alias already exists
+    Conflict(&'static str),
     #[error("{0}")]
     Extension(#[from] axum::extract::rejection::ExtensionRejection),
     #[error("{0}")]