Senior Software Engineer with 8 years shipping production software:
- 📱 15+ mobile apps to Google Play & the App Store — Flutter (8 production client apps), native Android (Kotlin/Jetpack), native iOS (Swift/SwiftUI), React Native
- 🛠️ Django/DRF backends — fintech, marketplace, insurance, telecom and SaaS.
- 📦 9 OSS libraries distilled from that work, across Dart, Python and Kotlin — token refresh, idempotency, offline queues, error envelopes, the transactional outbox
I've spent years on both sides of the API contract — so the backends I build are the kind I always wanted as a client developer: clean contracts, honest errors, and performance that holds up on real devices and real networks.
NovaBank — a full-stack banking platform (portfolio system: one backend, three clients, one contract):
| Repo | Stack | Highlights |
|---|---|---|
| novabank-api | Django · DRF · Celery · Channels | Idempotent payments on a double-entry ledger, RBAC, audit trail, WebSocket updates · 89 tests / 90% cov |
| novabank-flutter | Flutter · Bloc | Biometrics, secure storage, synchronized JWT refresh, offline-tolerant cache |
| novabank-android | Kotlin · Compose · Hilt | Lock-guarded refresh interceptor, Room cache, MVVM + Clean Architecture |
| novabank-ios | Swift · SwiftUI + UIKit | async/await client, Keychain, Face ID, xcodegen-managed project |
More products: marketpulse-api — marketplace backend with a 500k-product catalog, cursor pagination, cache-aside and stock-reserving checkout (measured: 1 vs 49 queries) · crewops-rn — offline-first React Native field app with a persisted mutation queue.
Dart / Flutter — sync_refresh: one refresh for concurrent 401s (single-flight, replay-once) · mutation_queue: offline-first persisted FIFO writes with retries and dead-lettering · idempotency: client-side idempotency keys that survive retries and restarts · poll_until: async polling with backoff, deadline and cancellation
Python / Django — django-idem: Stripe-style request idempotency for DRF · drf-envelope: uniform {error: {code, message, details}} envelopes with stable codes · django-event-outbox: transactional outbox with locked relay, retries and lease expiry · drf-request-id: request-ID middleware with ContextVar propagation and logging filter
Kotlin / JVM — auth-refresh: lock-guarded OkHttp token refresh with single replay and session teardown
Pairs worth noticing: idempotency (client) + django-idem (server) close the double-submit hole end to end; sync_refresh, auth-refresh, and the refresh logic inside the banking clients are the same contract in three languages.
Backend — Python · Django · DRF · GraphQL · Celery · Redis · Channels · PostgreSQL · Docker · GitHub Actions · Nginx/Gunicorn · AWS
Mobile — Flutter/Dart · Kotlin/Jetpack · Swift/SwiftUI/UIKit · React Native · Firebase · Room · Core Data
Practices — Clean Architecture · MVVM · TDD · SOLID · REST & GraphQL API design · CI/CD · code review
