Rust Micropayment API
High-Throughput Financial Engine
High-throughput, low-latency API designed for processing thousands of transactions per second with strict safety guarantees and fault tolerance.
The Problem
Node.js based payment gateways were struggling under burst loads, causing memory leaks and unacceptable latency spikes during peak transaction windows.
Architecture
Rewrote the core transaction processing engine in Rust using Actix-Web. Implemented a lock-free event-driven architecture using PostgreSQL for durable state and Redis for idempotency checks.
Decision Log
"Opted for Rust due to its memory safety guarantees without a garbage collector. Actix-Web was chosen over Tokio/Axum for its mature ecosystem and extreme performance benchmarks."
Performance
Optimization
Implemented connection pooling and prepared statements at startup. Replaced JSON parsing with highly optimized Serde binary formats for internal microservice communication.
Scaling Logic
The stateless API scales linearly. Bottlenecks at the DB level were mitigated by implementing a sharded PostgreSQL cluster based on user ID hashes.
Challenges
Handling concurrent transaction collisions. Implemented optimistic concurrency control (OCC) with automatic retries on version conflicts.
Final Impact
Reduced infrastructure costs by 80% while increasing theoretical maximum throughput by 15x. Zero memory leaks in production over 12 months.