Kotlin Developer

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 KotlinCollaborating with cross-functional teams to develop innovative solutions across Platform, Services, SMB, and other domainsAnalyzing system performance and implementing optimizations to ensure high reliability and scalabilityParticipating in code reviews, post-mortems, and providing mentorship to other engineersProactively improving the architecture and quality of solutions, and leading the team through technical challenges and migrations Requirements Minimum 5 years of professional experience in software developmentExpertise 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 GrafanaStrong problem-solving skills and a collaborative mindset to mentor and upskill your teammatesVery good knowledge of English - min. B2 levelResiding in Poland required Nice to have Previous work in the fintech industry or with financial productsKnowledge of topics related to payments, cards, or accountingExperience working in a scale-up environmentProficiency in one of the following front-end technologies: React or TypeScript Job no. JOB-ABBV7 Sii ensures that all hiring decisions are made solely on the basis of qualifications and competence. We are committed to equal and fair treatment of all, regardless of legally protected characteristics. At Sii, we promote a diverse and inclusive work environment, in full compliance with applicable anti-discrimination laws. Benefits For You Great Place to WorkSolid financial situationContracts with the biggest brandsCentre of internal trainingsMany experts you can learn fromOpen and accessible management teamProfit sharingPassion Sponsorship programRegular integration events and tripsComfortable and well-equipped officesMySii appMedical care