ABOUT THE COMPANY:
Join ADDENDUM, a global software development and IT team augmentation firm focusing on fintech, banking, and telco industries. Experience tailored benefits, diverse projects with various tech stacks, and opportunities for growth, freedom, and responsibility you desire.
ABOUT THE ROLE:
We are looking for a Lithuanian-speaking Java Developer based in Lithuania to join our team and contribute to the development of innovative internal software solutions.
This is an excellent opportunity for a mid-level developer with strong Java and Spring Boot skills, hands-on experience in Chrome browser extension development, and practical knowledge of AI/LLM integrations.
We are looking for someone proactive, independent, and comfortable working in a small team where product requirements evolve quickly. You will have the opportunity to take ownership of technical solutions, contribute to architectural decisions, and turn ideas into working products.
The role combines backend development, browser extension development, AI integration, and practical problem-solving, with a strong focus on security, privacy, and maintainable code.
WHAT YOU WILL BE DOING:
- Developing and maintaining backend applications using Java and Spring Boot, including REST APIs, data validation, configuration, and error handling.
- Designing, building, and improving browser extensions using TypeScript, primarily for Chrome (Manifest V3, service workers, content scripts), with potential Safari support.
- Integrating external AI/LLM APIs, including prompt design, structured outputs, error handling, timeout management, and cost optimization.
- Ensuring secure and privacy-conscious data processing, particularly when handling user browsing information and untrusted external content.
- Writing clean, maintainable, and easily adaptable code to support evolving product requirements.
- Developing automated unit and integration tests using tools such as JUnit and Vitest, including testing external integrations without relying on live APIs.
- Containerizing applications using Docker and supporting deployment, configuration, monitoring, and production stability.
- Implementing appropriate API protection mechanisms, including authentication, rate limiting, and abuse prevention.
- Translating product ideas and requirements into practical technical solutions, evaluating trade-offs, and contributing to technical decisions.
- Collaborating closely with the Product Owner and development team, maintaining clear technical documentation, and proactively identifying opportunities for improvement.
WHAT WE EXPECT:
- Fluency in Lithuanian and English. Currently based in Lithuania.
- Solid hands-on experience with Java and Spring Boot, including REST API development, configuration, validation, error handling, and testing.
- Practical experience with TypeScript and Chrome extension development, including Manifest V3, service workers, and content scripts.
- Experience integrating external AI/LLM APIs, including prompt design, structured responses, handling failures, timeouts, and API costs.
- Good understanding of web security and privacy principles, including secure API key management, user consent, sensitive data handling, input validation, and prompt injection risks.
- Experience writing automated tests using JUnit, Vitest, or similar frameworks, including mocking external dependencies.
- Familiarity with Git, Docker, environment-based configuration, HTTPS, and application logging.
- Ability to design simple, reliable, and maintainable solutions that can adapt to changing requirements.
- A proactive, self-driven attitude and willingness to take ownership of tasks independently.
NICE TO HAVE:
- Experience with Spring Security, OAuth2, JWT, and authentication mechanisms.
- Knowledge of caching and rate limiting using Redis, Caffeine, Bucket4j, or similar tools.
- Experience with cloud deployment, CI/CD pipelines, reverse proxies, or Cloudflare.
- Familiarity with Safari browser extension development.
- Experience with Chrome Web Store publishing and browser extension release processes.
- Knowledge of LLM output evaluation, including test datasets, quality metrics, and response validation.
- Experience with WXT, Vite, or similar browser extension development tools.
- Familiarity with payment integrations such as Stripe.
- Basic understanding of GDPR and accessibility standards (WCAG).
WHAT WE OFFER:
Salary ranges (for employees in Lithuania only): 3,500–5000 € gross (the given range is flexible and depends on your experience).
- Opportunity for long-term cooperation.
- Flexible cooperation model – employment or B2B.
At Addendum we believe in personalized benefits packages that cater to your unique passions. Tell us what drives you, and we'll craft a package accordingly. On top of that, here's what's in store automatically:
- Top Talent Collaboration: Join award-winning teams from different countries.
- Diverse, Challenging Projects: Break free from the ordinary with dynamic, stimulating work.
- Epic Team Events: Join us for summer and winter parties and online events.
- Learning & Development Opportunities: That new tech certificate is just around the corner.
- Special Celebrations: We love a good shindig for birthdays and project milestones.
So, get your dancing shoes on and come join the fun!
At ADDENDUM, we wholeheartedly reject all forms of discrimination, including but not limited to age, disability, sex, sexual orientation, pregnancy and maternity, race or ethnicity, religion or belief, gender identity, marriage, civil partnership, or any other protected category. We are committed to fostering a culture of equality and inclusion, where every individual has the opportunity to thrive.