Backend developer building APIs and event-driven services designed to stay correct under concurrency and failure.

• 🎓 Education: B.Tech Computer Science and Engineering (Data Science)
• 🧪 Quality engineering: testing, debugging, reliability, and edge cases, with automated test suites in node:test and pytest
• 🧩 Problem solving: 300+ problems solved on LeetCode
• 🏆 Hackathon: Top 5 at Dev Crafts Hackathon

I like building things, breaking them on purpose, and figuring out why they broke.

Payment and wallet backend focused on correctness under concurrency and partial failure, implemented two ways: a single service using the transactional outbox pattern, and event-driven microservices coordinated by a saga.

• 🔒 Idempotent transfers: SHA-256 payload fingerprinting with Redis and PostgreSQL checks, so a reused key with different details is rejected
• 🛡️ Safe concurrency: ACID transactions with ordered row-level locks to prevent deadlocks
• 📨 Reliable events: transactional outbox publishing to Kafka with retries, a dead-letter state, and idempotent consumers
• 🔄 Distributed transactions: saga orchestration with compensating actions across wallet, payment, and orchestrator services
• ✅ Tested: 27 unit and integration tests covering idempotency, refunds, auth guards, and duplicate event delivery

flowchart LR
    C["Client"] -->|"POST transfer<br/>+ idempotency key"| A["Express API"]
    A -->|"dedupe check,<br/>distributed lock"| R[("Redis")]
    A -->|"one ACID transaction:<br/>lock wallets, debit, credit,<br/>write outbox event"| P[("PostgreSQL")]
    P -->|"outbox poller<br/>(FOR UPDATE SKIP LOCKED)"| K["Kafka"]
    K -->|"at-least-once<br/>delivery"| E["Consumer"]
    E -->|"INSERT processed_events<br/>ON CONFLICT DO NOTHING"| P

📂 Source: distributed-payment-wallet (outbox pattern) and payment-wallet-system (saga microservices)

Job scheduling platform built with Node.js and BullMQ that runs asynchronous work through distributed queues and background worker pools.

• 📋 Job types: concurrent, delayed, and recurring (cron-style) jobs
• 🔁 Failure handling: automated retries with exponential backoff and a dead-letter queue
• 📦 Deployment: Docker and Kubernetes for horizontal scaling and fault tolerance

💻 Languages
⚙️ Backend & databases
☁️ Systems & cloud
🌐 Web
🧰 Tools & platforms

What I built at each stage

1️⃣		Foundations: Python and C++ Programming fundamentals, data structures, and algorithms. Built Road Safety AI (YOLOv8 and OpenCV, served with FastAPI, tested with pytest) and Map Router, a pathfinding visualizer comparing Dijkstra, A*, and Contraction Hierarchies.
2️⃣		The web: JavaScript and TypeScript Core JavaScript and TypeScript, applied in resume-coach, a Next.js app using Tailwind, Supabase auth, and the Groq API.
3️⃣		Backend: Node.js and Express Built ecommerce-backend, a REST API with JWT authentication, request validation, cart and order flows, Razorpay payments, and Swagger docs.
4️⃣		Databases: PostgreSQL and Redis Relational modelling and ACID transactions in PostgreSQL, with Redis for caching and distributed locks.
5️⃣		Event streaming: Kafka Asynchronous, event-driven design with a transactional outbox, at-least-once delivery, and idempotent consumers in distributed-payment-wallet.
6️⃣		Distributed systems Saga orchestration with compensating actions across three services in payment-wallet-system, plus a BullMQ job scheduler with exponential backoff and dead-letter queues, deployed with Docker and Kubernetes.
🔭		Now: system design and reliability Scalable backend architecture, fault tolerance, and cloud deployment.

Open to software engineering, backend, and QA roles.
Happy to talk backend engineering, testing, and distributed systems.

_{Code. Debug. Learn. Repeat.}