Implementing Real-Time Features

1. Implementing Chat Application

Example: Chat envelope

{ "type": "chat.send", "room": "general", "text": "hello", "clientId": "c1" }
{ "type": "chat.message", "id": "m42", "room": "general", "userId": "u1", "text": "hello", "ts": 1715900000 }
FeatureDetail
RoomsTopic per room
Typing indicatorThrottled events
Read receiptsAck per message id
HistoryHTTP fetch + WS for new
ModerationServer-side filters

2. Implementing Live Notifications

ChannelUse
user.{id}.notifPer-user inbox
Toast UIDisplay on receive
Service WorkerBackground push when tab closed
PersistenceServer stores unread

3. Implementing Real-Time Dashboard

PatternDetail
Initial snapshotHTTP fetch on load
Delta streamWS pushes patches
Throttle updatesrAF or 100ms window
CoalesceLatest state per key

4. Implementing Collaborative Editing

Example: Yjs over WebSocket

import * as Y from "yjs";
import { WebsocketProvider } from "y-websocket";
const doc = new Y.Doc();
const provider = new WebsocketProvider("wss://yjs.example.com", "room-42", doc);
const ytext = doc.getText("content");
ytext.observe(() => render(ytext.toString()));
ApproachDetail
CRDT (Yjs/Automerge)Conflict-free merges
OT (ShareDB)Server-coordinated
AwarenessCursor + presence
PersistenceSnapshot to DB periodically

5. Implementing Live Location Tracking

ElementDetail
Throttle1-5s updates
Delta encodingSend Δlat/Δlon
Geofence filterServer filters by bbox
BatteryReduce rate when stationary

6. Implementing Live Comments

FeatureDetail
Topic per postpost.{id}.comments
Live countAggregate event
ReactionsLightweight delta msgs
Spam filterServer-side

7. Implementing Game Multiplayer

PatternDetail
Tick rate20-60 Hz
Authoritative serverAnti-cheat
Client predictionMask latency
Server reconciliationReplay inputs after correction
Snapshot interpSmooth other players
Binary protocolMinimize bytes/tick

8. Implementing Live Audio/Video Signaling

Note: WebSocket carries SDP/ICE for WebRTC setup, not media. Media flows peer-to-peer via UDP.
MessageUse
offer / answerSDP exchange
ice-candidateConnectivity check
join / leaveRoom membership
renegotiateStream change

9. Implementing Live Cursor Sharing

Example: Throttled cursor

document.addEventListener("pointermove", (e) => {
  throttledSend({ "type": "cursor", "x": e.clientX, "y": e.clientY });
});
OptimDetail
rAF throttle~60 Hz cap
Delta coordsSmaller bytes
InterpolationSmooth other cursors
Hide on idle2s no-move

10. Implementing Real-Time Analytics

AspectDetail
AggregationServer windows by 1s/5s
Push interval1-5s
Subset by filterPer-dashboard filter
BackfillHTTP for last N min