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Karandeep Singh

@karansadana

Senior Backend Engineer / Tech Lead | Java 21 • Spring Boot 3 • Apache Kafka • Distributed Systems • PostgreSQL • AWS | 9+ Yrs Building Distributed Sy

India

Message

Senior Backend Engineer and Tech Lead with 9+ years of experience architecting high-throughput distributed systems in telecom and enterprise SaaS. Progressed from Software Engineer to Tech Lead at Kochar Infotech.

Key Impact:

- Architected a nationwide OTA platform updating 40M+ SIM cards at 99.98% delivery success during a multi-country telecom merger.

- Redesigned multi-tenant PostgreSQL schemas with Redis caching — slashing p95 query latency by 85% and cutting database CPU load by 50%.

- Engineered adaptive distributed throttling to protect telecom gateways (Kannel SMS Gateway) from traffic spikes.

- Mentored 3–5 engineers; standardized RCA runbooks that reduced MTTR by 40%.

Core Stack: Java 21, Spring Boot 3.x, Apache Kafka (KRaft), PostgreSQL, Redis, AWS (EC2, S3, RDS),OCI(Oracle Cloud Infrastructure), Resilience4j, Docker, Microservices, Event-Driven Architecture.

Open to: Senior Backend Engineer, Lead Backend Engineer, Staff Engineer, Technical Lead role.

Experience

Work history, roles, and key accomplishments

Current

Tech Lead

Current

Kochar Infotech

Jan 2025 - Present (1 year 9 months)

Spearheaded a nationwide OTA SIM campaign updating 40M+ SIM cards with a 99.98% success rate. Engineered heartbeat-based polling APIs with adaptive throttling and mentored 3-5 backend engineers.

Java Spring Boot Kafka PostgreSQL Redis AWS Docker CI CD Kannel SMS Gateway System Design Technical Mentorship

Senior Software Engineer

Kochar Infotech

Jan 2023 - Dec 2024 (1 year 11 months)

Redesigned multi-tenant PostgreSQL schemas and caching to cut p95 latency by 85% and database CPU load by 50%. Architected an asynchronous lifecycle tracking state machine and an extensible Rule Engine for OTA workflows.

Java Spring Boot PostgreSQL Redis Rules Engine Finite State Machines System Design

Software Engineer

Kochar Infotech

Jul 2019 - Dec 2022 (3 years 5 months)

Engineered high-throughput RESTful APIs and built a streaming CSV/ETL framework using PostgreSQL COPY for multi-million record datasets.

Java REST APIs PostgreSQL CSV ETL Apache Tomcat Oracle Weblogic

Senior Web Developer

Web Solutions-India

Apr 2018 - Jun 2019 (1 year 2 months)

Architected and secured high-throughput RESTful API backends for mobile applications. Optimized backend workflows and database queries, improving response times and throughput by 35%.

REST APIs Backend Development Database Optimization Security

Web Developer

Green Apple Media Solutions

Apr 2017 - Apr 2018 (1 year)

Developed custom database-driven web platforms, including an online bus reservation engine with real-time seat inventory locking and transactional booking flows in MySQL.

Web Development MySQL Database Design Transactional Systems