Transaction Processing API
Spring WebFlux + gRPC
As Software Engineer at Jama Wealth, architected reactive REST API gateway translating HTTP/JSON to gRPC/Protocol Buffers for internal microservices. Built with Spring Boot 3 WebFlux for non-blocking I/O. Implemented connection pooling, circuit breaker patterns, and comprehensive error mapping achieving high throughput with low latency.
The Challenge
Frontend applications needed RESTful APIs but backend microservices communicated via gRPC. Direct gRPC from browsers wasn't feasible. Needed a high-performance translation layer that wouldn't become a bottleneck, handling 5K+ RPS while maintaining sub-50ms latency and providing HTTP-friendly error handling.
The Solution
Built reactive REST gateway using Spring WebFlux with non-blocking gRPC clients. Implemented request/response translation between JSON and Protocol Buffers, connection pooling, circuit breakers, and comprehensive error mapping. Used R2DBC for reactive database operations and Redis for caching.
Technology Stack
Architecture
- Reactive programming model
- Non-blocking I/O (WebFlux)
- API Gateway pattern
- Protocol translation layer
- Connection pooling
- Circuit breaker and retry
- Request/response caching
- Distributed tracing
- Load balancing
- Horizontal pod autoscaling
Key Features
Results & Impact
- Architected reactive REST-to-gRPC gateway using Spring WebFlux
- Achieved 5,000+ RPS throughput with P95 latency 42ms
- Implemented connection pooling + backpressure handling for 100+ concurrent streams
- Optimized database queries from O(n²) to O(log n) using indexing strategies
- Reduced payload size 60% via Protocol Buffers vs JSON
- Deployed with circuit breaker patterns achieving 99.95% uptime