Senior Java Developer Gdańsk, Kraków, Warszawa Expert B2B 1 200 – 1 550 PLN/day

Jit; Polska; Hybride; PLN 240 000 - 320 000; Plein temps

Avantages offerts par ce poste

Jit Academy

Bonuses for content creators

Mental health support

Life insurance

Teambuilding events

Gym cards

Résumé du poste

Jit is seeking a Senior Backend Engineer to own end-to-end backend development for a high-performance trading ecosystem. You will build services for trading platform integrations, order management, and real-time risk calculations.

You will work with Java, Spring Boot, REST, and WebSocket APIs in a distributed microservice environment, collaborating with product and architecture teams to deliver reliable, scalable solutions.

Qualifications

• 8+ years of backend development experience.
• Commercial Java experience required.
• Spring Boot experience is essential.
• Experience with REST APIs and WebSocket integrations.
• Strong understanding of order lifecycle management.
• Experience with precision-critical financial calculations.

Responsabilités

• Design and develop backend services supporting trading platform integrations.
• Integrate external trading platforms using REST and WebSocket APIs.
• Implement and maintain order management workflows.
• Develop margin, risk and P&L calculation services.
• Ensure accuracy of financial calculations and currency handling.
• Collaborate with product, architecture and business stakeholders.

Connaissances

Backend development

Financial systems

REST API usage

WebSocket integrations

Problem-solving in real-time systems

Team collaboration

Formation

Engineering degree preferred

Outils

Java

Spring Boot

REST APIs

WebSocket APIs

Microservices

Order Management Systems

Real-time Data Processing

Description du poste

Remote: Warszawa, Gdańsk, Kraków (with 2-3 days in the office weekly)

Why choose this offer?

End‑to‑end ownership w ith a modern tech stack

Stability combined with continuous growth

Autonomy and high‑quality collaboration

Project

Join a team building and enhancing a high-performance trading ecosystem for global financial markets. You will work on backend services responsible for trading platform integrations, order management, margin calculations, profit & loss processing, and real-time communication with external trading systems.
This role requires deep expertise in financial systems, precision-sensitive calculations, and integrations with trading platforms through REST and WebSocket APIs.

Responsibilities you’ll have:

• Design and develop backend services supporting trading platform integrations
• Integrate external trading platforms using REST and WebSocket APIs
• Implement and maintain order management workflows
• Develop margin, risk and P&L calculation services
• Ensure accuracy of financial calculations, rounding rules and currency handling
• Optimize system performance and reliability in real-time environments
• Collaborate with product, architecture and business stakeholders
• Support production incidents and participate in system improvements
• Contribute to technical design decisions and backend architecture
• Leverage AI-assisted engineering tools to improve development efficiency and quality

Expected competences and knowledge:

• 8+ years of experience in backend development
• Strong commercial experience with Java
• Strong commercial experience with Spring / Spring Boot
• Experience integrating external systems through REST APIs
• Experience working with WebSocket-based integrations
• Strong understanding of order lifecycle management
• Strong understanding of margin calculations and P&L logic
• Experience with precision-critical financial calculations
• Knowledge of currency conversion, rounding rules and financial data processing
• Experience working in distributed systems and microservice architectures
• Experience within regulated financial services, brokerage, capital markets or trading environments
• Ability to discuss practical usage of AI tools in software engineering processes
• Engineering degree is highly preferred

Nice to have:

• Experience with TraderEvolution
• Experience building trading platforms or brokerage solutions
• Knowledge of market data feeds and trading workflows
• Experience with low-latency or real-time systems

Technologies you’ll work with

• Java
• Spring Boot
• REST APIs
• WebSocket APIs
• Microservices
• Order Management Systems
• Real-time Data Processing

Client – why choose this particular client from the Jit portfolio?

Our client is an international financial services organization operating in the capital markets domain, focused on processing and analyzing large volumes of transactional data. The company develops modern data platforms that support trading, operational efficiency, and regulatory reporting. It operates in a fast-paced, highly regulated environment with a strong emphasis on scalability, data quality, and advanced analytics.

About Jit Team

The Human Factor of IT – it’s not just a slogan, it’s a philosophy. The foundation of Jit Team is people, which is why we prioritise you. We employ over 770 experienced experts, to whom we offer developmental projects, a wide range of benefits, and a proprietary professional development programme. Together with clients from around the world, we create innovative IT solutions delivered by highly specialised and efficient teams.

Behind our maxim are also charitable and educational activities. We support schools, universities, and educational institutions by conducting workshops, running educational projects, sponsoring events, and donating learning equipment. We offer internships that help launch careers in IT. We support water rescuers and hospitals by providing the necessary equipment. We also support numerous charitable organisations helping people in need, children, and the elderly. We are a Polish company and we share what we have achieved over more than 15 years of activity. By supporting local initiatives, we contribute to the circulation of good energy.

Here’s how we get from first “hello”
to “welcome aboard”

You’ll meet with our HR team to discuss your experience, approach to software development, and teamwork. We’ll also verify your English language proficiency as part of the conversation. Then, you’ll take part in atechnical interview focused on your skills and problem-solving mindset.

We believe agreat workplace is more than a set of benefits. It’s about trust, long-term relationships, and an environment where people can do their best work.

Share and gain experience. Jit Academy is aplatform serving amutual knowledge exchange. Lecture others and share your expertise or join the audience.

Jit Communities

Join the group of experts. We ensure constant growth, that’s why we keep building communities dedicated to mutual education.

Growth support

We value people who are looking to develop their skillset. We proudly finance avariety of courses and certifications so that you can gain new competencies.

Jit Summer Office

Gain access to the office located at the very beach in Chałupy. Jit Trailer awaits visits of the team members and their families.

Jit Boats

Cruise the bay thanks to the motorboat awaiting at the Yacht Park in Gdynia. Furthermore, there is afleet of jet skis and kites located at the beach in Chałupy.

Would you recommend any IT specialist we could hire? Share the contact and gain abonus if we hire them.

Start the day without haste.
At Jit, we begin and finish the day of work within acertain time frame, in stead of fixed hours.

Bonuses for content creators

We provide bonuses to those willing to participate in industry events as public speakers, and to content creators writing articles for our blog.

Mental health support

Mental health is fundamental. Take advantage of psychologists and psychotherapists’ support and reach for psychoeducational content on the wellbeing platform

We provide our teams with high-quality gear necessary to work. Choose between MacOs or Windows and work the way you prefer.

Teambuilding events

Meet new, interesting people. We’re dedicated to building human relations and often host informal events that bound our team members.

Classes conducted for small groups, lectured
by our teachers, guarantee rapid results.

Take care of your wellbeing. Members of Jit Team, gain access to awide range of medical plans provided by Medicover or PZU.

We provide Multisport and Medicover Sport gym cards so that you can improve your physical condition.

Life insurance

Increase your safety. No matter the form of employment, we provide life insurance plans to our colleagues.

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