WebSockets & live updates
Persistent connections that push changes to the app the instant they happen, with automatic reconnection when networks drop.
App Backend & API · Real-Time & Push Notifications · AI-First · Results-Driven
Real-Time & Push NotificationsLive Updates That Keep Users Engaged
Short answer: Real-time and push notifications are the backend features that let an app update instantly and reach users even when the app is closed: live chat and feeds over WebSockets, presence and typing indicators, and push notifications delivered through Apple's APNs and Google's Firebase Cloud Messaging. Done well, updates feel immediate and notifications arrive reliably without draining battery; done poorly, messages lag, duplicate, or silently fail. Zen in Tech builds real-time systems in-house using WebSockets and managed services like Pusher, Ably and FCM, with retries and delivery tracking wired in. Judge the work on latency, reliable delivery, and how gracefully it scales as concurrent users climb.
When "instant" is the feature
Real-time means the app reflects changes the moment they happen, without the user refreshing: a new message appears, a dashboard number ticks up, a driver's location moves on a map. Push notifications extend that reach beyond the open app, tapping the user on the shoulder through the operating system even when your app is in the background or closed. Both turn a static app into something that feels alive and brings people back.
The engineering is about reliable delivery at scale, not just sending a message. Live updates ride on WebSockets or server-sent events, backed by a pub/sub layer so thousands of clients can be notified at once. Push runs through Apple Push Notification service and Firebase Cloud Messaging, which means device-token management, retries, and respecting each user's notification preferences. Watch for connections that silently drop and never reconnect, notifications that arrive twice or not at all, and real-time systems that work in a demo but collapse under real concurrency.
Because we build the real-time layer as part of your backend, updates flow from the same source of truth as the rest of the app, so what a user sees live always matches what is actually stored. We add reconnection handling, delivery tracking and per-user notification controls from the start, and reach for proven services like Pusher, Ably or FCM when they save you from running fragile infrastructure yourself.
What we cover
What our real-time & push work covers
Push notifications (iOS & Android)
Reliable delivery through Apple's APNs and Firebase Cloud Messaging, including device-token management and deep links into the app.
In-app messaging & chat
One-to-one and group chat with history, read receipts and typing indicators, built on a scalable messaging backend.
Presence & live status
Online/offline presence, typing indicators and live location or status, so users see what's happening in the moment.
Event streaming & pub/sub
A publish/subscribe layer (Redis, Kafka, SNS/SQS) that fans out events to many clients and services without bottlenecks.
Delivery, retries & analytics
Retries, deduplication and delivery tracking so you know messages actually arrived, plus per-user notification preferences.
Services
Real-time & notification services we deliver
From a first chat feature to scaling a live system under heavy load, here is how we build the real-time layer behind your app.
Real-time feature build
Design and build chat, live feeds, collaborative editing or live dashboards from scratch, backed to scale.
Push notification setup
Wire up APNs and FCM, handle device tokens, deep links and preferences, so notifications land reliably on iOS and Android.
Add real-time to an existing app
Introduce live updates or push to a product that currently makes users refresh, without rebuilding the whole backend.
Notification preferences & routing
Give users control over what they receive and how, with smart routing across push, email and SMS.
Scaling an existing real-time system
Diagnose and fix a live feature that stutters or drops connections under load, and re-architect it to handle real concurrency.
Event-driven backend architecture
Design a pub/sub or event-streaming backbone so real-time features and background jobs stay decoupled and reliable.
Tools & platforms
The real-time stack we build on
The exact toolset depends on your goals — these are the platforms we use most, and we work with whatever your team already relies on.
Real-time transport
WebSocketsSocket.IOServer-Sent Events
Managed real-time
PusherAblyFirebase Realtime DatabaseSupabase Realtime
Push services
Apple Push Notification service (APNs)Firebase Cloud Messaging (FCM)OneSignal
Messaging & queues
Monitoring
Chosen per project — not a fixed menu. Have a preferred tool or platform? We’ll work with it.
Built to last
Secure, Accessible & Built to Last
We build on modern, well-supported frameworks with security and accessibility baked in — dependency hygiene, input validation, HTTPS and WCAG-minded UI — so your product is safe and usable from day one.
You own all the code and assets. Everything ships with documentation and a clean handover, so your team (or ours) can maintain and extend it without lock-in.
Who we work with
Industries We Build For
20+ years across sectors — in Houston and internationally.
Transparent pricing
Estimate your project in seconds
Pick what you’re building for an indicative range, then request an exact quote. No email wall.
Simple prices for typical tasks
- App APIfrom $10k
- Backend + authfrom $18k
- Realtime / scalefrom $25k
- Care planfrom $1k/mo
Proof
700+ projects, 20+ years
See the products and growth work we’ve shipped across industries — and request a case study relevant to yours.
How we work
Fixed scope. Sprints. Working software.
- 01
Scope & fixed estimate
A short discovery call turns your idea into a clear spec and a firm range — free.
- 02
Design & architecture
UX, data model and stack chosen for your scale, not ours.
- 03
Build in sprints
Working software every 1–2 weeks — you see progress, not promises.
- 04
Launch & scale
We ship, measure and keep improving with care plans.
FAQ
Real-time & push notifications: frequently asked questions
How much do real-time features or push notifications cost?
It depends on scope. Adding push notifications to an existing app is often a few thousand dollars, while a full chat or live-collaboration system costs more. Real-time work is usually scoped inside a backend build, which typically starts around $10,000. We confirm the exact figure on a free call once we understand what needs to update live and at what scale.
What is the difference between real-time updates and push notifications?
Real-time updates change what the user sees while the app is open, for example a new message appearing instantly in an open chat, usually over WebSockets. Push notifications reach the user through the operating system even when the app is closed or in the background, delivered via Apple's APNs and Google's FCM. Most engaging apps use both together.
How long does it take to add real-time or push?
Adding push notifications to an existing app typically takes one to two weeks including testing on real devices. A full real-time feature like chat or a live dashboard takes longer because it involves connection handling, scaling and storage. We give a firm timeline once we know the feature and your expected concurrency.
Should you use WebSockets or a managed service like Pusher or Ably?
Managed services like Pusher, Ably or Firebase remove the burden of running and scaling your own WebSocket infrastructure, which is often the faster, more reliable choice, especially early on. Self-hosted WebSockets make sense when you need full control or want to avoid per-message fees at very high volume. We recommend the fit for your scale and budget on a free call.
Do you build real-time features for businesses outside Houston?
Yes. We are based in Houston but build real-time and push systems for clients across Texas, the USA, and internationally. This work is delivered remotely, and real-time infrastructure can be hosted in whichever region keeps latency low for your users.
Do you help Houston businesses add live features to their apps?
Absolutely, it is our home market. Our office is at 9800 Richmond Ave in the Westchase / Energy Corridor area, and we can meet in person to plan chat, notifications or live updates for your app. Everything is built in-house by our own specialists.
Why do my push notifications arrive late or not at all?
Common causes are expired or unmanaged device tokens, missing retry logic, hitting APNs or FCM rate limits, or the operating system throttling background delivery to save battery. We audit the whole delivery path, fix token handling and retries, and add delivery tracking so you can see exactly what arrived and what did not.
Make your app feel alive
From live chat to reliable push, we'll build the real-time layer your app needs, backed to scale. Get a free estimate from our in-house Houston team.
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