Tomas Klaus

Detail-oriented and results-driven Junior Backend Developer specializing in Java and Python. Experienced in building scalable REST APIs, microservices, containerized infrastructure, and cloud integration architectures (SQL/NoSQL). Proven track record of quick technology adaptation through successful freelance delivery and independent modular system development. Capable of efficient asynchronous technical communication in international environments.

Freelance Backend Developer - Upwork / Independent Contract

(2026-05)

• Designed and built an automated SaaS integration platform utilizing TypeScript and Meta Services for call center communication workflows.
• Engineered a robust web application architecture by designing and optimizing high-performance RESTful APIs to ensure reliable end-to-end data integrity.
• Containerized the entire application infrastructure using Docker and Docker Compose, managing frontend, backend, and database layers within isolated environments for seamless local testing and deployment.

Junior Backend Developer - Personal & Independent Projects

(2022-10 - 2023-11)

• Developed and maintained modular backend applications utilizing Java, Spring Boot, and Maven build automation.
• Implemented core CRUD operations, input validation, global exception handlers, and secure communication protocols.
• Integrated relational database designs with PostgreSQL and MySQL, leveraging JPA/Hibernate for data persistence.
• Tested API endpoint reliability and request/response metrics utilizing Postman and JUnit testing tools.

Online Software Development Programs - Advanced Java Programming, Object-Oriented Structures, and Backend Fundamentals - UC San Diego & Duke University (Extension Programs) (2022 - 2023)