WebSocket and Real-time API Development — order chats, notifications, live updates

Users don't see messages in real time, notifications arrive with delay, and online chat lags? REST is not suitable for this — you need WebSocket or SSE. Bidirectional communication channel, instant delivery, scaling via Redis Pub/Sub. Works where REST is powerless.

What We Offer

Development of real-time API is the creation of systems where data is delivered instantly. Chats, notifications, collaborative editing, stock quotes, online games — any scenario where message delivery speed matters.

WebSocket — full bidirectional communication channel over TCP. Minimal latency, persistent connection without re-establishment
Server-Sent Events (SSE) — lightweight protocol for one-way event transmission from server to browser. For notifications and update feeds
Scaling — WebSocket via Redis Pub/Sub or RabbitMQ for horizontal scaling. Thousands of concurrent connections on a single node.
Security — WSS (WebSocket Secure), authentication during connection establishment, incoming message validation

WebSocket · SSE · Pub/Sub · Redis · WSS

Real-time Use Cases

Real-time covers a wide range of tasks. From simple notifications to multi-user collaboration. We choose the protocol for each specific scenario.

Chats and Messengers

WebSocket for instant message delivery. Status support: online, offline, typing. Message history, files, reactions. Group and private chats.

Notifications and Alerts

SSE for lightweight event delivery to the browser. Push notifications via WebSocket. Filtering by type, priority, user. Guaranteed delivery.

Real-time Collaboration

Operational Transform for collaborative editing. WebSocket for cursor synchronization. OT algorithms or CRDT for conflict resolution.

Real-time is when the user receives a message faster than they can think "why the silence." We build systems where latency is measured in milliseconds, not seconds.

— Studio Principles

WebSocket SSE Redis Pub/Sub RabbitMQ Socket.IO WSS Node.js Python Docker

Full Cycle of Real-time Development

Real-time systems are not just WebSocket. We design architecture that withstands thousands of concurrent connections and guarantees delivery of every message.

Connection Architecture — WebSocket vs SSE vs long-polling. We choose the protocol for the task. We design rooms and channels for group messaging.
Scaling — Redis Pub/Sub for message exchange between nodes. Horizontal scaling of WebSocket servers with shared state.
Real-time on Node.js — WebSocket servers on Node.js with Socket.IO or ws. Integration with REST API and existing backend.

Delivery Guarantees — at-most-once, at-least-once, exactly-once. Acknowledgment, retransmission on connection loss.
Monitoring — active connections, throughput, latency. Prometheus + Grafana for real-time metrics.
REST + WebSocket Hybrid — REST for request-response and WebSocket for push notifications. Optimal architecture for modern applications.

WebSocket with Redis Pub/Sub — Scaling Without Limits

Redis Pub/Sub allows horizontal scaling of WebSocket servers. A message sent on one node is instantly delivered via Redis to all other nodes. Thousands of connections — one queue.

Why Choose Real-time Development With Us

Order real-time API — get a system where data is delivered instantly, connections are reliable, and scaling is built into the architecture.

Guaranteed Delivery

We implement at-least-once and exactly-once semantics. The message will arrive even during temporary connection loss — acknowledgment queue and retry mechanism.

Scaling

Redis Pub/Sub, horizontal scaling of WebSocket servers. Thousands of concurrent connections per instance, millions — per cluster.

Connection Monitoring

Grafana dashboards: active connections, throughput, latency. Alerts in Telegram when connection quality drops.

                WebSocket connection example:

                const ws = new WebSocket("wss://api.example.com/ws");

                ws.onmessage = (event) => {

                  // Instant notification without polling

                  showNotification(JSON.parse(event.data));

                };

                ws.onclose = () => ws.reconnect(); // Automatic reconnection

Real-time is when the user doesn't wait. We build systems where latency is measured in milliseconds, and message delivery is guaranteed even during connection loss.

— Studio Principles

WebSocket Development — real-time API with instant message delivery