Senior Java Developer (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

Regular integration events

Job summary

Sii Poland is hiring for a senior Java backend role in Warsaw, building a large-scale platform for a leading financial institution in the capital markets. You will work in a distributed team to modernize critical systems using cloud technologies, automation, and AI-assisted software development practices.

You will design and enhance cloud-based backend services, own components across their lifecycle, and collaborate with business and operational teams to boost efficiency and reliability in a

Qualifications

• 5+ years of professional backend Java experience.
• Knowledge of modern frameworks and microservices.
• Experience with containerization and cloud-native platforms.
• Familiar with CI/CD and source control processes.
• Strong analytical and detail-oriented approach.
• Fluent English and ability to work in a hybrid setting (office 3 days/week).

Responsibilities

• Design, develop, and enhance cloud-based backend services for transaction platforms.
• Own selected components from architecture to production support.
• Leverage AI-powered development tools to accelerate design and coding.
• Collaborate with business and ops teams to improve automation and efficiency.
• Ensure reliability, scalability, and performance of distributed systems.
• Support continuous improvement in software delivery and monitoring.

Skills

Java backend

Frameworks

Event-driven

Microservices

Cloud-native

CI/CD

Source control

Hybrid work

English

Tools

Docker

Kubernetes

Job description

Join an international technology team delivering solutions for a leading financial institution operating in the capital markets sector. In this role, you will contribute to the development of a large-scale platform supporting the processing and completion of financial transactions. Working within a distributed engineering environment, you will help modernize critical systems through cloud technologies, automation, and AI-assisted software development practices. This position offers the opportunity to collaborate with both technical and business stakeholders while building highly available, enterprise-grade solutions.

Your tasks

• Designing, developing, and enhancing cloud-based backend services supporting transaction processing platforms
• Taking ownership of selected system components throughout their entire lifecycle, from architecture and implementation to production support
• Leveraging AI-powered development tools to accelerate software design, specification, and coding activities
• Collaborating with business and operational teams to improve efficiency through automation and technology-driven solutions
• Contributing to the reliability, scalability, and performance of distributed systems operating in a global environment
• Supporting continuous improvement initiatives related to software delivery, monitoring, and operational excellence

Requirements

• At least 5 years of professional experience in backend software development using Java
• Strong knowledge of modern application frameworks, event-driven architectures, and microservices development
• Hands-on experience with containerization and orchestration platforms in cloud-native environments
• Familiarity with CI/CD practices, source control systems, and modern software delivery processes
• Strong analytical and problem-solving skills combined with attention to quality and detail
• Fluent English and willingness to work in a hybrid model, including regular office presence three days per week

Job no. JOB-TLUNK

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