Yiannis Koul

I’m a full-stack developer with extensive experience designing and building scalable microservices, web, and mobile applications across research, lotteries, airline ticketing, and SMS campaigns. I focus on efficient, maintainable, high-quality software and I enjoy connecting frontend experiences to reliable backend systems.

In my recent work, I design and develop scalable microservices using Node.js, NestJS, and GraphQL, manage PostgreSQL databases, and deliver Angular-based frontend solutions. I also implement automated testing with Playwright and deploy services on AWS to keep releases dependable and repeatable.

Earlier roles strengthened my backend depth and integration skills: I built an SMS campaign platform with SpringBoot (Reactor, CQRS) and MongoDB, developed REST APIs for data management, and created internal release-management tooling with Express.js. I’ve also architected event-driven, asynchronous workflows with Apache Camel, built lottery gaming interfaces with ReactJS, delivered automated testing with Protractor, and worked on a warehouse census Android mobile web app using Sencha Touch—along with ERP systems and IT infrastructure experience.