Real-time Notification Center with WebSocket, Laravel & React

Real-time Notification Center Implementation

Imagine your SaaS product processing hundreds of events per minute – new orders, comments, task statuses. Users complain they miss important notifications, and the admin panel is overloaded. On one project, 20,000 users simultaneously generated 500 notifications per second, and without proper architecture, the system crashed. After implementing our solution, server load decreased by 70%. We solved this problem by deploying a real-time notification center built on Laravel + WebSocket + React. Under the hood: an optimized database model, asynchronous delivery, and well-thought-out UX.

Problems Solved by the Notification Center

Traditional polling solutions create excessive server load: a database query every 5 seconds. With 1,000 active users, that's 200 RPS just for checking notifications. WebSocket (Laravel Echo + Pusher) provides a push model: notifications arrive instantly without extra requests. This reduces TTFB by 3–4 times and improves Core Web Vitals. For example, after implementation on a project with 5,000 DAU, complaints about notification delays dropped by 90%. Another issue is lost notifications due to broken architecture: the client may miss an event if the WebSocket connection is lost. Our solution uses Laravel queues with automatic retries and a delivery confirmation mechanism.

WebSocket Driver Selection

Pusher is best for quick start, Soketi and Reverb for full control and cost savings with many users. The choice depends on SLA requirements: SaaS provides predictable cost, self-hosted lowers infrastructure expenses. For small projects, Pusher is enough; for enterprise systems with tens of thousands of connections, Soketi is better.

Laravel Broadcasting enables real-time push notifications via WebSocket, reducing latency to under 50ms.

Database Structure and Indexes

Why indexes in the notifications table matter?

Without indexes, queries for unread notifications scan the entire table. On a table with millions of rows, this leads to timeouts. We use a covering index on (user_id, read_at, created_at DESC), which speeds up sorting and filtering by 10 times. The notifications table can reach 10 million rows, and without indexes, queries take 5–10 seconds instead of 50 ms. This structure ensures fast inserts and selects, with the index covering 95% of queries.

CREATE TABLE notifications (
    id         UUID         PRIMARY KEY DEFAULT gen_random_uuid(),
    user_id    INTEGER      NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    type       VARCHAR(100) NOT NULL,
    icon       VARCHAR(50),
    title      VARCHAR(255),
    body       TEXT,
    url        VARCHAR(500),
    data       JSONB        NOT NULL DEFAULT '{}',
    read_at    TIMESTAMPTZ,
    created_at TIMESTAMPTZ  NOT NULL DEFAULT NOW()
);

CREATE INDEX ON notifications(user_id, read_at, created_at DESC);

Optionally, add an index on type for filtering by category.

Laravel: API Endpoints and Broadcasting

class NotificationController extends Controller
{
    public function index(Request $request): JsonResponse
    {
        $notifications = auth()->user()->notifications()
            ->latest()
            ->limit(50)
            ->get();

        return response()->json([
            'notifications' => NotificationResource::collection($notifications),
            'unread_count'  => $notifications->whereNull('read_at')->count(),
        ]);
    }

    public function markRead(Request $request): JsonResponse
    {
        $query = auth()->user()->notifications()->whereNull('read_at');

        if ($request->id) {
            $query->where('id', $request->id);
        }

        $query->update(['read_at' => now()]);

        return response()->json(['success' => true]);
    }

    public function send(User $user, array $data): void
    {
        $notification = $user->notifications()->create($data);
        broadcast(new NotificationCreatedEvent($user->id, $notification))->toOthers();
    }
}

Laravel Echo + WebSocket: Client Integration

// hooks/useNotifications.ts
import Echo from 'laravel-echo';
import Pusher from 'pusher-js';

window.Pusher = Pusher;
const echo = new Echo({
  broadcaster: 'pusher',
  key: import.meta.env.VITE_PUSHER_KEY,
  cluster: import.meta.env.VITE_PUSHER_CLUSTER,
  forceTLS: true,
});

export function useNotifications(userId: number) {
  const [notifications, setNotifications] = useState<Notification[]>([]);
  const [unreadCount, setUnreadCount] = useState(0);

  useEffect(() => {
    api.get('/api/notifications').then(({ data }) => {
      setNotifications(data.notifications);
      setUnreadCount(data.unread_count);
    });

    const channel = echo.private(`notifications.${userId}`)
      .listen('.NotificationCreated', (event: { notification: Notification }) => {
        setNotifications(prev => [event.notification, ...prev].slice(0, 50));
        setUnreadCount(c => c + 1);

        if (Notification.permission === 'granted') {
          new Notification(event.notification.title ?? 'New notification', {
            body: event.notification.body ?? undefined,
            icon: '/icon-192.png',
          });
        }
      });

    return () => channel.stopListening('.NotificationCreated');
  }, [userId]);

  const markAllRead = async () => {
    await api.post('/api/notifications/mark-read');
    setNotifications(prev => prev.map(n => ({ ...n, read_at: new Date().toISOString() })));
    setUnreadCount(0);
  };

  return { notifications, unreadCount, markAllRead };
}

React: UI Component

function NotificationBell({ userId }: { userId: number }) {
  const { notifications, unreadCount, markAllRead } = useNotifications(userId);
  const [isOpen, setIsOpen] = useState(false);

  return (
    <div className="notification-bell">
      <button
        onClick={() => setIsOpen(!isOpen)}
        aria-label={`${unreadCount} unread notifications`}
        aria-expanded={isOpen}
        aria-haspopup="true"
      >
        🔔
        {unreadCount > 0 && (
          <span className="badge" aria-hidden>{unreadCount > 99 ? '99+' : unreadCount}</span>
        )}
      </button>

      {isOpen && (
        <div className="notification-panel" role="dialog" aria-label="Notifications">
          <header>
            <h2>Notifications</h2>
            {unreadCount > 0 && (
              <button onClick={markAllRead}>Mark all read</button>
            )}
          </header>

          <ul>
            {notifications.length === 0 && <li className="empty">No notifications</li>}
            {notifications.map(notification => (
              <li key={notification.id} className={notification.read_at ? 'read' : 'unread'}>
                {notification.url ? (
                  <a href={notification.url}>{notification.title}</a>
                ) : (
                  <span>{notification.title}</span>
                )}
                <time dateTime={notification.created_at}>{timeAgo(notification.created_at)}</time>
                {notification.body && <p>{notification.body}</p>}
              </li>
            ))}
          </ul>
        </div>
      )}
    </div>
  );
}

Work Process and Timelines

How is the stability of real-time notifications guaranteed?

We guarantee 99.9% uptime for the notification center. We use queues (Laravel Queues) with retry logic on failures. On the client — automatic reconnection via Echo (Reconnect). For Pusher — fallback to SSE. For self-hosted — monitoring via Laravel Horizon and Telegram alerts. We have years of experience with complex web applications and over 20 notification center implementations. A transparent process ensures you get a working solution within agreed timelines.

1. Analysis — we review requirements, load, and select the WebSocket driver.
2. Design — design DB schema, API, events.
3. Implementation — write code, test on staging.
4. Testing — load tests (10,000+ connections), fallback verification.
5. Deployment — set up production environment, monitoring.

What's Included

• Documentation: architecture, DB schema, event sequence, environment setup.
• Code: backend (Laravel), frontend (React), queue and broadcasting configuration.
• Access to repository and CI/CD.
• Team training: 1–2 online meetings.
• Support: 1 month after deployment.

Investment in a notification center pays off through reduced load and increased user loyalty. To get a ready-made solution, contact us — we will audit your project and propose the optimal architecture. Request a consultation with our engineers.

Implementation Timeline

Basic integration: 2–3 days. Self-hosted WebSocket (Soketi/Laravel Reverb): +1 day. If custom grouping or filtering logic is needed, timeline is discussed separately.

Development of Real-Time Systems: WebRTC, SSE, WebSocket

We know how painful it is when polling kills the server. One of our projects—an online auction platform—used polling every 2 seconds. Under a load of 400 participants, the server received 12,000 HTTP requests per minute for a single bid. 90% of responses were empty. After switching to WebSocket, the load dropped 15 times, saving approximately $3,000 per month on server costs. Order custom real‑time functions development—get a ready solution with a stability guarantee.

Implementing real‑time in production is not just a library. We design the architecture for load, scenarios, and budget. Below is a breakdown of key solutions with examples.

Choosing the Right Real-Time Transport for Your Project

Three Real-Time Transports: When to Choose Which

Server‑Sent Events work over regular HTTP/1.1 or HTTP/2. The browser opens a connection, the server keeps it open and pushes events in text/event-stream format. Automatic reconnection is built-in—no need for reconnect logic. Limitation: server → client only. Ideal for notifications, progress of long tasks, live feeds.

WebSocket is a full‑duplex channel after an HTTP Upgrade handshake. Browser and server exchange frames in both directions. Suitable for chats, collaborative editing, games, trading terminals. Requires separate reconnect logic and heartbeat (ping/pong every 30 seconds, otherwise NAT tables close the connection). The WebSocket protocol enables full‑duplex communication with minimal overhead (RFC 6455).

WebRTC is peer‑to‑peer audio/video and data directly between browsers, bypassing the server. A server is needed only for signaling (STUN/TURN for NAT traversal). A TURN server is required in 20–30% of cases (corporate networks, symmetric NAT). For a telemedicine service, we implemented WebRTC: audio latency dropped from 800 ms (via relay) to 50 ms—a 16‑fold improvement. The TURN server was needed only for 15% of sessions, saving significant traffic costs.

How to Properly Choose a Transport: Step-by-Step Guide

1. Determine the data exchange scenario: unidirectional (server → client) — SSE; bidirectional with low latency — WebSocket; audio/video — WebRTC.
2. Evaluate latency requirements. If below 500 ms is acceptable — SSE; for below 100 ms and bidirectional — WebSocket; for below 50 ms and P2P — WebRTC.
3. Check the infrastructure budget. SSE uses regular HTTP servers, WebSocket requires keeping connections in memory, WebRTC may require a TURN server (from a certain cost per TB of traffic).
4. Consider scaling: for 100k+ connections, consider a WebSocket gateway (Centrifugo, Pushpin).

What Is CRDT and How Is It Better Than Operational Transformation?

Collaborative editing is not just "whoever writes last wins". Without a conflict merging algorithm, two users insert text at position 45; the first saves—the position shifts; the second saves on top—the operation applies to an outdated state. Text gets duplicated or lost.

OT (Operational Transformation) requires a server to resolve conflicts; CRDT (Conflict‑free Replicated Data Types) works without a central coordinator. Yjs is the most mature CRDT library for the browser. It integrates with ProseMirror, TipTap, CodeMirror, Monaco Editor. CRDT (Yjs) is 5 times faster than OT for concurrent editing under high load.

Library comparison for collaborative editing

Issue: the Yjs document size grows due to operation history. Periodic garbage collection is needed—snapshot the document and clean old operations. Without it, a document worked on for a year may weigh 50 MB.

const ws = new WebSocket('wss://example.com');
let pingInterval;

ws.on('open', () => {
  pingInterval = setInterval(() => {
    ws.ping();
    setTimeout(() => {
      if (ws.readyState === WebSocket.OPEN) ws.terminate();
    }, 5000);
  }, 25000);
});

ws.on('close', () => clearInterval(pingInterval));

Common Mistakes in Real-Time Implementation and How to Avoid Them

Typical Mistakes in Real‑Time Implementation

Memory leak on the server—forgetting to remove the event handler when the connection closes. On Node.js, heap grows ~1 MB/hour. EventEmitter warns about 10+ listeners, but it's not always noticed.

Thundering herd on reconnect. The server goes down for 30 seconds, comes back—10,000 clients try to reconnect simultaneously. Exponential backoff with jitter is mandatory: delay = Math.min(baseDelay * 2^attempt + random(0, 1000), maxDelay).

Lack of connection lost indication. WebSocket doesn't always notify about disconnection (e.g., phone enters a tunnel). Heartbeat solves the problem.

Work Process

We start by choosing the transport for the scenarios—sometimes all three are needed in one project: SSE for system notifications, WebSocket for chat, WebRTC for video calls. We design the message protocol (JSON with type and payload, less often binary via MessagePack). We develop with race condition testing—this is not covered by unit tests.

Load testing with k6 + k6/experimental/websockets: we simulate 5,000 concurrent connections with a real pattern. Our engineers are certified in WebSocket and WebRTC, guaranteeing 99.9% stability.

What's Included in the Delivery

• Real‑time layer architecture (transport selection, message protocol)
• Implementation with load testing (k6, race condition scenarios)
• Backend integration via Redis Pub/Sub or similar bus
• Protocol and data schema documentation
• Team training
• Technical support for 2 weeks after launch

Why Centrifugo May Be More Cost-Effective Than Socket.io?

Socket.io is easier to set up (1–2 days), but Centrifugo built on Go handles 1M+ connections on a single node. For 100k concurrent clients, Centrifugo saves up to 40% on infrastructure costs, which translates to $2,000 per month compared to Socket.io. Get a consultation—we'll help you choose the stack for your load.

Timeline

• Basic WebSocket chat or notifications on top of existing API: 1–3 weeks.
• Collaborative editor with Yjs and persistence: 4–8 weeks.
• WebRTC video calls with recording: 6–12 weeks (significant part is integration with media server mediasoup or Janus).

Contact us to evaluate your project. Discuss your task with an engineer—we'll assess complexity and timeline individually.