Senior backend engineer with 5+ years building production-grade Ruby on Rails APIs. Currently at Tadarab owning payment architecture, subscription systems, and B2B SaaS infrastructure for a growing EdTech platform in Kuwait.
What I specialize in:
- 💳 Payment gateway integrations — Checkout.com, HyperPay, Deema, PayPal, Tap, Tamara, Apple Pay/IAP — reduced billing failures by 80%
- 📦 Subscription, wallet & referral engines — 25% upsell boost, 50% improvement in subscriber retention
- 🏗️ Multi-tenant B2B SaaS with org-scoped access control & automated AWS Amplify provisioning
- ⚡ Real-time systems — Action Cable, Redis pub/sub fan-out, WebRTC signaling
Former Senior Technical Mentor at Microverse — reviewed code and mentored 100+ developers worldwide across Ruby on Rails and JavaScript.
A production-grade payment gateway — built as a complete, multi-repo system
Paygate is a full-stack payment infrastructure portfolio: a REST API, merchant dashboard, developer documentation site, and a drop-in JavaScript SDK (@paygater/js) published on npm. Engineered with financial-grade patterns: double-entry ledger, idempotency, HMAC-signed webhook delivery, and a charge state machine.
| paygate-api | paygate-dashboard | paygate-docs | paygate-js | |
|---|---|---|---|---|
| Role | Core API & billing engine | Merchant UI | Developer docs | Client-side JS SDK |
| Stack | Rails 8.1 · PostgreSQL · Sidekiq | Next.js 15 · TypeScript · shadcn/ui | Next.js 15 · Fumadocs · MDX | TypeScript · Stripe.js |
| Deployed | Fly.io | Vercel | Vercel | npm · jsDelivr CDN |
| Live | OpenAPI Spec ↗ | Dashboard ↗ | Docs ↗ | npm ↗ |
POST /v1/charges
│
▼
AuthenticateRequest ← API key (sk_test_xxx) or JWT session
│
▼
IdempotencyService ← Redis 24h lock per Idempotency-Key header
│
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PaymentRouterService ← Strategy pattern: routes by payment_method + environment
│
├── StripeAdapter → Visa / Mastercard / Apple Pay
└── CheckoutAdapter → Mada
│
▼
ChargeService ← State machine · double-entry ledger · audit log
│
▼
WebhookDispatcherService → Sidekiq → HMAC-SHA256 signed · exponential retry (5 attempts)
Charge lifecycle: PENDING → AUTHORIZED → CAPTURED → REFUNDED / FAILED / VOIDED
Key design rules:
- Business logic lives in
app/services/— controllers call one service and render - Financial data is never cached — always read live from the database
- Every financial state change writes a double-entry
LedgerEntry - Every merchant action writes an immutable
AuditLog - No PAN, CVV, or raw card data ever touches the server — client-side tokenization only
| Layer | Technology |
|---|---|
| Framework | Rails 8.1 (API mode) |
| Database | PostgreSQL — charges table range-partitioned by created_at |
| Cache / Queues | Redis + Sidekiq 8.1 |
| Auth | bcrypt API keys + JWT sessions + Rack::Attack rate limiting |
| Payment adapters | Stripe 13 (Visa/MC/Apple Pay) · Checkout.com REST (Mada) |
| Serialization | Blueprinter |
| Logging | Lograge — structured JSON, no PAN |
| API spec | rswag — OpenAPI 3.0.1, 260 request examples |
| Deployment | Fly.io (web + worker machines) |
Backend
Auth & Security
Payment & Integrations
Cloud & DevOps
Monitoring & Observability
Testing & Quality
Frontend (supporting)
Technical deep-dives on backend engineering, distributed systems, and production architecture.
| Article | Topic |
|---|---|
| Idempotency in Distributed Systems: 5 Patterns Every Backend Engineer Should Know | Distributed systems · Payments |
| Webhooks: How External Systems Talk Back to Yours — Securely | Webhooks · HMAC · Event-driven |
| The Complete Software Architecture Walkthrough | System design · Rails architecture |
| When the Cloud Burns: Why RTO and RPO Aren't Just Buzzwords | Disaster recovery · Infrastructure |
| Boosting API Performance with Caching in Rails | Rails · Performance · Caching |
Building things that process real money, serve real users, and stay up.