Backend Software Engineer (Java/Python)

github

Harjas Romana  • Peerlist

Engineered a distributed task orchestration engine solving the double-execution problem for time-sensitive background jobs. Implemented a two-layer synchronization model: Redis-based distributed leader election for single-scheduler guarantee, and PostgreSQL FOR UPDATE SKIP LOCKED for concurrent multi-worker queue draining without contention. Built a self-healing Janitor service for zombie task recovery from crashed nodes and an exponential backoff algorithm to prevent thundering herd scenarios.

Chronos — Distributed Fault-Tolerant Task Orc

Deployed a highly available e-commerce backend on AWS EC2 with Auto Scaling Groups behind Elastic Load Balancers. Implemented Redis cache-aside topology to offload MySQL. Sustained 99.9% uptime under simultaneous connections.

Cloud-Native E-Commerce Backend

Built a semantic code search engine enabling natural language querying across large codebases. Engineered a vector embedding pipeline for 1,000+ functions with sub-second retrieval latency using ChromaDB. Designed for developer onboarding acceleration.

CodeAura — Semantic Static Analysis Engine

Designed a Sliding Window rate limiter protecting backend microservices from burst traffic. Offloaded all concurrent state-management to Redis using atomic Lua scripts on Sorted Sets, eliminating distributed race conditions without lock latency overhead. Validated with 1,000+ simultaneous threads via ExecutorService stress tests. Zero dropped limits.

Distributed API Rate Limiter & Security Gatew

Built a Spring Boot producer/consumer ecosystem integrated with Kafka for high-throughput async data ingestion, decoupled from a React visualization UI and Python ML training pipelines.