Looking for a job

devender issar

@devenderissar

Message

I build reliable Java backend services for payment and advertising platforms.

India

Message

What I'm looking for

I'm looking to build production-ready Java backend services, contribute to scalable microservices and API design, and own features through deployment and production support.

I built and supported high-scale payment and advertising platforms at Samsung Research Institute, including backend services for ad auctions, delivery, reporting, and Samsung Pay integrations.

I designed REST APIs for TV ad serving, integrated Demand Side Platforms, and improved API reliability through OpenAPI 3 validation and stricter error handling. I also integrated UPI and wallet partners including Paytm, Mobikwik, and Freecharge for local payment flows.

Since 2021, I've deepened my Spring Boot, Hibernate/JPA, microservices, system design, testing, CI/CD, and AWS deployment skills through freelancing and hands-on service development.

Experience

Work history, roles, and key accomplishments

Current

Freelance Java Developer

Current

Self Employed

Jan 2021 - Present (5 years 8 months)

Freelanced on Java/Spring Boot tasks including API integrations, bug fixes, feature enhancements, and deployments. Focused on clean architecture and production-ready code.

Java Spring Boot Hibernate JPA REST APIs Microservices System Design CI CD AWS

Software Engineer (Samsung Pay)

Samsung Research Institute

Jun 2014 - Jun 2021 (7 years)

Integrated India payment methods (UPI) and wallet partners (Paytm, Mobikwik, Freecharge) for local user flows. Improved critical transaction stability by strengthening edge-case handling and payment flow validations.

Java 8 Android UPI Payment Integration Debugging Root Cause Analysis

Software Engineer

Samsung Research Institute

Jun 2014 - Jun 2021 (7 years)

Built and maintained backend services for ad auctions, delivery, and reporting across Samsung mobile apps and Samsung TV. Designed REST APIs for TV ad serving and integrated multiple Demand Side Platforms (DSPs) to expand ad demand.