Bablu Kumar Singh
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Backend Systems

High-Throughput API Gateway

Node.jsExpress.jsRedisDockerJWTNginx
High-Throughput API Gateway

The Problem

Microservices suffered from erratic traffic spikes, lack of centralized token validation, and rate-limiting issues that degraded downstream systems.

Architecture & Topology

Custom proxy server built with Node.js, Express, and Redis Cluster, acting as a reverse proxy, rate limiter, and JWT authenticator.

Request Workflow Map:
Client -> Nginx (SSL) -> API Gateway (Auth & Rate Limit via Redis) -> Downstream Microservices

Engineering Challenges

Parsing token validation and executing IP-based token bucket rate limiting under 5ms overhead.

Applied Solutions

Configured Lua scripts in Redis to execute atomic rate-limiting checks. Token blacklisting is updated in memory using Redis Pub/Sub.

Results & Benchmarks

Centralized routing for 5 microservices, maintaining sub-10ms response latencies while shielding database clusters from denial-of-service traffic.

API Routing Specifications

MethodPathObjective
ALL/proxy/*Forward request to downstream destination
POST/api/auth/invalidateRevoke and blacklist JWT token

Performance Tuning

Implemented streaming file proxying to avoid loading heavy payloads in node RAM. Fine-tuned keep-alive connections on HTTP agents.

Lessons Learned

Lua scripting inside Redis guarantees operations are executed atomically without racing conditions.