December 17, 2025

Senior Java Fullstack Developer

Senior • Hybrid

Warsaw, Poland

Sii ensures that all employment-related decisions are made solely on the basis of qualifications and competencies. We are committed to equal treatment of all individuals, regardless of any protected characteristics, and promoting a diverse and inclusive work environment.

We are looking for an experienced Senior Full Stack developer focused on leading projects, mentoring team members, and ensuring high-quality deliverables. As an senior developer, you will contribute to the development and enhancement of eMobility (EV) platforms and management systems, working on microservices architecture, cloud integration, and API development. You will gain hands-on experience in enterprise-level application development while collaborating with senior developers, architects, product managers and other roles involved in SDLC.

Your tasks

Lead the design of complex systems
Ensure the best practices of coding
Mentor team members
Collaborate with stakeholders
Drive technical innovation and best practices
Oversee technical direction and architecture

Requirements

At least 6 years of experience in Java (17+) and the Spring framework
Previous work on the front-end with TypeScript, Angular, RxJS, CSS, and HTML
Deep understanding of systems architectures and infrastructure
Proficiency in optimisation of web applications, state management and REST API
Familiarity with container orchestration (Docker, Kubernetes) and cloud platforms (AWS/Azure)
Knowledge of Git and CI/CD pipelines
Fluency in English and Polish
Residing in Poland required

What we offer

Great Place to Work since 2015 - it’s thanks to feedback from our workers that we get this special title and constantly implement new ideas
Employment stability - revenue of PLN 2.1BN, no debts, since 2006 on the market
We share the profit with Workers - over PLN 76M has already been allocated for this aim since 2022
Attractive benefits package - private healthcare, benefits cafeteria platform, car discounts and more
Comfortable workplace – class A offices or remote work
Dozens of fascinating projects for prestigious brands from all over the world
PLN 1 000 000 per year for your ideas - with this amount, we support the passions and voluntary actions of our workers
Investment in your growth – meetups, webinars, training platform and technology blog – you choose
Fantastic atmosphere created by all Sii Power People

Join the Sii team – develop your skills, gain experience, and build your career!

Sii

Sii is a company recognized as a "Great Place to Work" since 2015, thanks to employee feedback and the implementation of new ideas. Established in 2006, Sii has demonstrated financial stability with a revenue of 2.1 billion PLN and no debts. The company shares its profits with employees, having allocated over 76 million PLN for this purpose since 2022. Sii offers a rich benefits package, including private healthcare, a cafeteria platform, and discounts on cars. Employees can work in comfortable A-class offices or remotely. Sii is involved in numerous fascinating projects for prestigious global brands and invests 1 million PLN annually to support employee passions and volunteer actions. The company emphasizes personal development through meetups, webinars, a training platform, and a technology blog. Sii is characterized by a fantastic atmosphere created by its "Sii Power People."