Kotlin Developer (f/m/x)

Join a team working on a modern fintech platform that supports company expense management. The project focuses on developing a finance solution that enables seamless integration of financial tools (including payment cards, expense management, and invoice handling) directly into partner systems such as banks, accounting platforms, and HR solutions. The product being developed allows companies to simplify financial processes, automate settlements, and gain full real-time control over their spending.

Your tasks

• Leading initiatives to design, build, and maintain scalable microservices primarily using Kotlin

• Collaborating with cross-functional teams to develop innovative solutions across Platform, Services, SMB, and other domains

• Analyzing system performance and implementing optimizations to ensure high reliability and scalability

• Participating in code reviews, post-mortems, and providing mentorship to other engineers

• Proactively addressing technical debt and guiding the team through technical challenges and migrations

Requirements

• Minimum 5 years of professional experience in software development

• Expertise in server-side languages, especially Kotlin, and experience with distributed systems, microservices, and cloud environments (e.g., AWS, Kubernetes)

• Proficiency with relational databases like PostgreSQL, testing frameworks (e.g., JUnit, Testcontainers), and observability tools like Grafana

• Strong problem-solving skills and a collaborative mindset to mentor and upskill your teammates

• Very good knowledge of English - min. B2 level

• Fluent Polish required

• Residing in Poland required

Nice-to-have requirements

• Previous work in the fintech industry or with financial products

• Knowledge of topics related to payments, cards, or accounting

• Experience working in a scale-up environment

• Proficiency in one of the following front-end technologies: React or TypeScript

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 

If you want to work on systems with high operational significance — apply now!