I build reliable backend systems with a focus on concurrency control, transactional consistency, distributed architecture, and secure API design.
| Backend | Java 21 · Spring Boot 3 · Spring Security |
| Data | PostgreSQL · MySQL · Spring Data JPA · Hibernate · Raw JDBC |
| Caching | Redis (Cache-Aside · Rate Limiting · Atomic ID Generation) |
| Payments | Stripe Checkout · Webhook Ingestion (HMAC-verified) |
| Infrastructure | Docker · Docker Compose · GitHub Actions CI/CD |
| Testing & Docs | JUnit 5 · Mockito · Testcontainers · SpringDoc OpenAPI |
| Auth & Identity | Keycloak · JWT · RBAC · Token Rotation |
| Migrations | Flyway |
- Distributed Systems
- Concurrency Control (Pessimistic / Optimistic Locking)
- Transactional Consistency & Idempotency
- Authentication & Authorization (JWT, RBAC, Token Rotation)
- Event-Driven Architecture
- Caching & Rate Limiting
- Payment Integration
- API Design
- Design for correctness before optimization.
- Keep business logic independent from infrastructure.
- Prefer explicit consistency over hidden side effects.
- Build systems that remain predictable under concurrent workloads.
| Project | What it does | Stack |
|---|---|---|
| BloodBridge | Blood donation matching platform with governorate-based fallback matching, JWT security hardening, outbox pattern, and QR-based verification flows. | Spring Boot · PostgreSQL · Redis · Keycloak |
| WhatsApp Clone API | Real-time messaging API with WebSocket/STOMP, presence tracking, and media handling. | Spring Boot · WebSocket/STOMP · Keycloak · MinIO · Redis |
| CalCounter | AI-powered nutrition tracking — photograph a meal and the AI identifies the food and calculates calories automatically. | Spring Boot · MySQL · JWT · HuggingFace |
| AttendPro | Attendance management system. | Spring Boot · PostgreSQL |
| Time-Table | University timetable generator producing PNG, PDF, and Excel outputs. | Spring Boot · Apache Batik · Flying Saucer |
| URL Shortener | Lightweight URL shortening service. | Spring Boot · Redis |
