Open to opportunities

Raj Kumar

@rajkumar18

Message

Senior Backend Engineer specializing in scalable cloud-native systems.

India

Message

What I'm looking for

I seek senior backend roles where I can architect scalable cloud-native systems, lead engineering teams, modernize legacy platforms, and drive performance and cost optimizations in an Agile environment.

I am a Senior Backend Engineer with 10+ years building scalable, distributed, and cloud-native applications using Ruby on Rails and AWS. I focus on architecting resilient backend services, modernizing legacy systems, and driving measurable performance improvements.

At Thinkbiz Technology I led a backend team of four, delivered large-scale SaaS applications, and improved system scalability and response time by 30% through query optimization and caching. I migrated legacy services to AWS ECS and automated CI/CD, cutting deployment time from 30 minutes to 4 minutes.

Previously, I delivered 10+ production-grade Rails applications, managed AWS infrastructure (ECS, Lambda, S3, DynamoDB, RDS), Dockerized services, and boosted test coverage to reduce production bugs. I built mission-critical modules that reduced processing delays by 40% and implemented centralized logging to improve incident detection.

I bring hands-on expertise in RESTful API design, microservices, PostgreSQL, Redis, and CI/CD pipelines, and I mentor engineers while managing sprints and code reviews. I seek opportunities to design secure, high-performance backend systems and lead engineering efforts that deliver clear business value.

Experience

Work history, roles, and key accomplishments

Team Lead – Backend

Thinkbiz Technology Pvt. Ltd.

Jul 2022 - Oct 2025 (3 years 3 months)

Led a backend team of 4 engineers to deliver large-scale SaaS applications, improving scalability and response time by 30% and cutting deployment time from 30 to 4 minutes through ECS and GitHub Actions automation.

Ruby on Rails AWS ECS PostgreSQL Docker GitHub Actions Microservices Cloudwatch CI CD

Senior Software Developer

I-Serve Systems Pvt. Ltd.

May 2018 - Jul 2022 (4 years 2 months)

Delivered 10+ production-grade Rails applications and built secure, scalable REST APIs while managing AWS infrastructure and Dockerizing services to enable CI/CD and 25–30% performance improvements.