Senior Java Developer- banking industry (f/m/x)

Sii Poland; Warszawa; Hybrid; PLN 180,000 - 240,000; Full time

Benefits offered by this job

Great Place to Work

Centre of internal trainings

Profit sharing

Medical care

Regular integration events and trips

Open and accessible management team

Job summary

Sii Poland in Warsaw seeks a senior software engineer to design scalable backend systems for real-time financial processing, including liquidity forecasting, resource optimization, and cash management. You will work with business stakeholders and engineers to craft data-driven applications using Java, microservices, APIs, and event-driven architectures in a hybrid setup.

The role emphasizes high availability, performance, and robust data processing with strong English communication.

Qualifications

• 5+ years in software development using Java and OO concepts.
• Strong expertise in relational databases, data modelling and system architecture.
• Experience building highly available, scalable business-critical applications.
• Knowledge of REST, distributed systems, messaging platforms, and modern practices.
• Willingness to hybrid work with Warsaw office 3 days/week.
• Excellent analytical, problem-solving and communication skills in English.

Responsibilities

• Design scalable full-stack applications based on object-oriented principles.
• Translate business and technical requirements into reliable software solutions.
• Build data processing components, analytical services, and automated tools supporting business decisions.
• Collaborate with internal stakeholders, end users, and cross-functional teams.
• Participate in full software development lifecycle including architecture, implementation, testing, and deployment.
• Develop solutions based on distributed systems, event-driven architectures, APIs, and microservices.

Skills

Java

Object-oriented programming

Relational databases

System architecture design

REST-based services

Distributed systems

Microservices

English communication

Tools

SQL

Data modelling

Messaging platforms

Job description

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 tasks

• 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

Requirements

• 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

Job no. JOB-J9CLH

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 Work
• Solid financial situation
• Contracts with the biggest brands
• Centre of internal trainings
• Many experts you can learn from
• Open and accessible management team
• Profit sharing
• Passion Sponsorship program
• Regular integration events and trips
• Comfortable and well-equipped offices
• MySii app
• Medical care