# Mohit Kumar — Senior Backend Engineer

> Senior Backend Engineer specializing in high-throughput distributed systems, financial infrastructure, event-driven microservices, and scale engineering. Built Apple Pay Later backend at Pine Labs, Flexi Credit BNPL platform, and institutional digital asset transfer systems for Galaxy Digital at Publicis Sapient.

## Core Technical Specialization
- **Languages**: Java, Python, SQL, JavaScript, TypeScript
- **Distributed Systems & Event Streaming**: Apache Kafka (AWS MSK, Confluent Cloud), RabbitMQ, Distributed State Machines, Idempotent Transaction Ledgers, Real-Time Replay Frameworks
- **Cloud & Container Infrastructure**: AWS (EKS, EC2, CloudFront, S3, Secrets Manager), Kubernetes, Docker, NGINX Reverse Proxy Bridging
- **Databases & Caching**: PostgreSQL, Redis Cluster, MySQL, Elasticsearch, TimescaleDB
- **Observability & Reliability**: OpenTelemetry, Datadog, Grafana, Distributed Tracing, SLO/SLI Management

## High-Impact Career Accomplishments
- **Apple Pay Later (Pine Labs)**: Architected the complete backend for Apple Pay Later integration with HDFC Bank. Built real-time eligibility engine (<200ms p99 latency), approval state machines, and real-time disbursement pipelines serving millions of users.
- **Flexi Credit BNPL Platform (Pine Labs)**: Launched BNPL lending platform processing INR 150M+ monthly across 85,000+ merchants with instant credit approvals up to INR 500K. Built real-time AML and fraud detection system preventing INR 360M+ in risk exposure.
- **Digital Asset Infrastructure (Publicis Sapient / Galaxy Digital)**: Engineered digital asset transfer workflows integrating Fireblocks and institutional exchanges with threshold-based rebalancing engines and zero-downtime microservice migrations from EC2 to EKS.
- **Adda247 Scale Engineering**: Optimized edtech platform for 10M+ monthly active users, reducing P90 API latency from 800ms to 150ms (81% drop) and database load by 70% using AWS CloudFront edge caching and Redis clusters.

## Published Technical Articles & System Designs
- Zero-Downtime Event Streaming Migration: RabbitMQ to AWS MSK Kafka
- Zero-Downtime Migration: Spring Boot Microservices from EC2 to Kubernetes
- MSK to Confluent Cloud: Enterprise Kafka Replay & Rollback Framework
- High-Throughput Disbursement Pipeline for Instant BNPL Approvals
- EdTech Edge Caching: 10M+ MAU Latency Reduction Architecture
- Idempotent Distributed Ledger Transactions in Financial Microservices

## Links & Contact Information
- Website: https://mkumar.in
- Email: mohitkumar4706@gmail.com
- Phone: +91-9599748565
- GitHub: https://github.com/mohitkum4r
- LinkedIn: https://linkedin.com/in/mohitkum4r
- Location: Gurugram, India