Oleksandr Kasianenko

 I'm a backend Node.js developer with 3 years of hands-on experience building scalable, well-tested APIs using TypeScript, NestJS, PostgreSQL, and Docker. I’ve worked on both monolithic and microservice architectures, focusing on clean code, test coverage (Jest, Mocha), and secure integration of third-party services.

I specialize in:

Building REST APIs with NestJS/Fastify/Express

Microservices architecture and system refactoring

Database design with PostgreSQL and MongoDB

Writing maintainable, tested, production-ready code

Docker-based environments & Git version control

I’m fast-learning, responsible, and communicative — ready to deliver clean backend solutions that scale.