Engineering An AI Speech Platform & First-Party Deep Linking For ~25k Learners
The deep linking, friends system and real-time features Abdul Rafay built as a contract Mobile App Developer at Accentify — a high-retention pronunciation coaching ecosystem combining React Native, Node.js, Socket.io real-time peer interactions, RevenueCat subscription monetization, and a custom first-party deep linking engine (link.accentify.co.uk) with AppsFlyer deferred install attribution.
Abdul Rafay worked on Accentify as a contract Mobile App Developer for the Accentify team; it is not a RafayLabs client.
Scaling Across ~25,000 Registered Learner Profiles
Architecture Highlights
~25,000+ LEARNERS
Active Pronunciation CommunityScaled user base practicing systematic accent reduction through a modular Course → Lesson → Level → Unit hierarchy.
100% UNVEXED DEEP LINKING
First-Party Domain (link.accentify.co.uk)Bypassed vendor short-link TTL expiration with proprietary permanent profile URLs, cold/warm app routing, and AppsFlyer deferred install handoffs.
<50MS SOCKET EVENTS
Socket.io Social State MachineReal-time peer presence, instant friend request handshakes across 5 relationship states, and live activity feeds.
CROSS-PLATFORM REVENUECAT
Seamless SubscriptionsUnified Apple App Store & Google Play in-app purchases, entitlement gating, and virtual reward monetization.
Solving Broken Viral Attribution & Pronunciation Coaching Friction
In mobile speech and language training, viral user acquisition hinges on one critical interaction: an existing learner sharing their profile link with friends on WhatsApp or social media.
However, traditional deep-linking tools rely on third-party short-links (e.g. AppsFlyer OneLink short URLs) which suffer from strict TTL (time-to-live) expiration. When shared links expired, invited users who installed the app were dumped on a generic onboarding screen, completely losing the inviting friend's context and dropping conversion rates by over 55%.
Furthermore, language apps commonly tie referral URLs to mutable handles (@username). When learners updated their username, every link previously shared on forums, YouTube descriptions, or group chats broke permanently.
The mandate: Architect a proprietary first-party deep linking domain (link.accentify.co.uk) with permanent, un-expiring public profile identifiers, seamless cold/warm app navigation, AppsFlyer deferred install handoffs, and a real-time peer community powered by Socket.io.
- •Vendor short-links that expire after 30–60 days, breaking public links
- •URL bound to username; changing @handle invalidates all shared links
- •New install drops user on blank home screen, losing friend connection
- First-party domain (link.accentify.co.uk) with zero TTL expiration
- Stable immutable publicProfileId independent of handle renames
- Deferred installation handoff preserves destination post-onboarding
The Deep Linking Infrastructure
Abdul Rafay authored Accentify's complete deep-linking infrastructure specification, ensuring that external URLs reliably open the intended in-app learner profile across every execution path:
Phase 1: Permanent First-Party Domain
Rather than sharing fragile vendor short links with TTL expiration, Accentify owns canonical links (link.accentify.co.uk/friend/{publicProfileId}). Uncapped, permanent, and safe for social sharing.
Phase 2: Cold & Warm Native Interception
If the user has Accentify installed, the operating system directly opens the native app, executes deep-link parsing, and navigates immediately to the target profile without browser hops.
Phase 3: Deferred Installation Routing
If uninstalled, the user lands on the App Store / Google Play. Post-install, AppsFlyer preserves destination metadata, allowing the app to open directly on the inviting friend's profile immediately after onboarding.
Phase 4: Stable Public Identifiers
Public URLs decouple completely from mutable @usernames. Changing a username never breaks historical referral links shared on WhatsApp, Instagram, or email.
1. User taps 'Share Profile' → Generates https://link.accentify.co.uk/friend/p7f9a2bc
2. Friend clicks link on iOS/Android:
↳ IF App Installed: iOS Universal Links / Android App Links invoke native routing directly → opens Target Profile.
↳ IF App NOT Installed: Browser redirects to long OneLink → App Store / Google Play → Stores deferred install token.
3. Onboarding complete → AppsFlyer callback delivers target payload → App navigates to inviting friend automatically.
Real-Time Peer Social Graph & Audio Engine
Pronunciation coaching requires persistent practice partners. Abdul Rafay engineered a robust 5-state relationship machine and an asynchronous daily coaching audio pipeline:
5-State Relationship Machine
Manages strict peer interactions between learners: None,Request Sent,Request Received,Friends, andBlocked, with atomic MongoDB mutations.
Tip of the Day Multi-Modal Audio
Coaches publish daily audio lessons (up to 50MB) streamed from Azure Blob Storage with custom waveform playback, threaded coach replies, and UTC timezone normalization.
Socket.io Real-Time Handshake
Bi-directional websocket events broadcast friend request updates, coach comments, and online learner presence with sub-50ms latency across Node.js/Express clusters.
The Accentify Engine Blueprint
The technical pillars engineered for Accentify—deferred viral deep linking, real-time social state machines, audio streaming, and RevenueCat subscription infrastructure—directly translate to four high-retention consumer verticals:
EDTECH & MICRO-LEARNING PLATFORMS
Duolingo / Babbel BlueprintCourse hierarchy with modular unit progression, daily speech practice, automated streak rewards, and peer-to-peer friend leaderboards that drive 70%+ Day-30 retention.
AUDIO-FIRST SOCIAL & COMMUNITY NETWORKS
Clubhouse / Airchat BlueprintLive audio rooms, asynchronous voice notes, real-time participant status via Socket.io, and threaded coach audio replies with sub-second websocket delivery.
GAMIFIED HABIT & ACCOUNTABILITY APPS
Strava / Habitica BlueprintDaily habit verification ('Tip of the Day' engine), mutual peer accountability circles, custom user profile cards with 5 relationship states, and digital coin economies.
B2B AI SPEECH & SALES COACHING SUITES
Gong / Poised BlueprintEnterprise audio evaluation pipeline analyzing speech clarity, pacing, filler-word frequency, and accent modulation with granular manager feedback consoles.