Yaroslav

YAROSLAV KOLOMOIETS
Java Developer
Ústí nad Labem, Czech Republic | [open contact info](look above in the "contact info" section) | [open contact info](look above in the "contact info" section)
LinkedIn | GitHub

PROFILE
Java Developer with hands-on experience across the full software development lifecycle — from database architecture to cloud deployment. Specialized in the Spring Boot ecosystem: building scalable, production-ready REST APIs with Spring Boot 3, Spring Security, Hibernate, and Docker. Independently architected, built, and shipped a backend application running on a live cloud server. Currently extending the same project with an Angular frontend, delivering a complete full-stack solution. Strong foundation in clean architecture, automated testing, and DevOps practices.
WORK EXPERIENCE
Java Developer - Self-employed
April 2024 – Present
Ústí nad Labem, Czech Republic
• Designed and implemented a production-ready RESTful API using Spring Boot 3 and layered architecture.
• Deployed and managed the application on a Linux VPS (DigitalOcean) using Docker Compose.
• Configured Nginx as a Reverse Proxy and secured the application with HTTPS/SSL certificates.
• Orchestrated container networking and managed DNS records for the production environment.
• Integrated MySQL database using Spring Data JPA and Hibernate; managed schema versioning with Liquibase.
• Implemented Spring Security with JWT-based Role-Based Access Control (RBAC).
• Wrote unit and integration tests using JUnit 5 and Mockito.
• Integrated third-party APIs: Dropbox API for secure file storage, Swagger UI for interactive API documentation.
• Followed SOLID principles and clean code practices throughout the full development lifecycle.
PROJECTS
Task & Project Management — Full-Stack Application | Live Demo | GitHub
Production backend deployed on a live cloud server, with Angular frontend in active development.
• Designed and deployed a production-ready REST API for task and project management on DigitalOcean VPS.
• Tech stack (backend): Java 17, Spring Boot 3, MySQL, Docker Compose, Nginx, JWT, Liquibase, Swagger UI.
• Building Angular frontend using OpenAPI Generator to auto-generate typed TypeScript service clients from the REST API specification.
• Tech stack (frontend): Angular, TypeScript, OpenAPI Generator, HTML, CSS.

Online Book Store — Secure Book Management System | GitHub
• Secure backend for book management with user authentication and role-based access control.
• Tech stack: Java 17, Spring Boot, Spring Security, Hibernate, MySQL, Maven.

NBA Statistics Bot & Web Application | GitHub
• Telegram bot integrating a public NBA REST API to deliver real-time player and team statistics on user request.
• Companion web application with interactive team cards and social media integration.
• Tech stack: JavaScript, HTML, CSS, Telegram Bot API, REST API integration.

TECHNICAL SKILLS
Core Java
Java 17, Java Core, Collections, OOP, SOLID, Multithreading
Spring Framework
Spring Boot 3, Spring Web (MVC), Spring Security, Spring Data JPA
Databases
MySQL, Hibernate, JDBC, Liquibase, SQL
DevOps / Cloud
Docker, Docker Compose, Linux (Ubuntu VPS), Nginx, HTTPS/SSL, DigitalOcean
Testing
JUnit 5, Mockito — unit & integration tests
Frontend
Angular, TypeScript, OpenAPI Generator, HTML, CSS, JavaScript
Tools & APIs
Maven, Git, Swagger/OpenAPI, Dropbox API, IntelliJ IDEA
Languages
Czech B2, English B1, German B1, Ukrainian (native)
EDUCATION
Jan Evangelista Purkyně University (UJEP)
Faculty of Applied Informatics
2025 – Present

Zaporizhzhia Electrical Technical College
Professional Junior Bachelor in Software Engineering
2020 – 2024
CERTIFICATES & COURSES
• Mate Academy — Java Developer Course (OOP, Java 8+, Spring Boot, Hibernate)
• FreshCode — Fullstack JS Developer Course
• Czech Language Certificate — Level B2