Senior Java Developer - banking industry (f/m/x) w Warszawa, Polska

Expected, Java, Apache Kafka, PostgreSQL, SDLC, Spring, REST

Optional, Apache Spark, AI

About the project, Join a long-term technology initiative within the financial sector focused on building advanced systems that support liquidity forecasting, financial resource optimization, cash management, and strategic decision-making. In this role, you will contribute to the development of high-performance, data-driven applications that process large volumes of business-critical information in real time. Working closely with business stakeholders and engineering teams, you will help design innovative solutions leveraging modern backend technologies, distributed architectures, event-driven processing, and emerging AI capabilities.

Your responsibilities, Designing and developing scalable full-stack applications based on object-oriented principles, Translating business and technical requirements into reliable, maintainable software solutions, Building data processing components, analytical services, and automated tools supporting business decision-making, Collaborating with internal stakeholders, end users, and cross-functional engineering teams, Participating in the full software development lifecycle, including architecture, implementation, testing, and deployment, Developing solutions based on distributed systems, event-driven architectures, APIs, and microservices

At least 5 years of experience in software development using Java and object-oriented programming concepts, Strong expertise in relational databases, data modelling, and system architecture design, Experience building highly available, scalable, and resilient business-critical applications, Practical knowledge of REST-based services, distributed systems, messaging platforms, and modern development practices, Openness to working in a hybrid model, including regular presence in the Warsaw office (3 days per week), Excellent analytical, problem-solving, and communication skills, along with fluent spoken and written English

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 – you can change them thanks to Job Changer application, 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

Recruitment stages, Send your CV, Talk to us about your expectations, Learn more about our projects and choose the best, Start your adventure with Sii!

Sii Sp. z o.o., Sii is the leading technology consulting, digital transformation, engineering, and business services vendor in Poland. We already employ more than 7 300 professionals and implement projects in a variety of industries for clients from many countries around the world. The Great Place to Work title, won 10 times in a row, proves that at Sii, we create a friendly work environment., , 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.

This is how we work,