Fullstack (Java + React)

B3 Consulting Poland; Warszawa; Hybrid; PLN 180,000 - 240,000; Full time

Benefits offered by this job

Health benefits

Sports benefits

Speed Coaching

Team activities

Job summary

B3 Consulting Poland is seeking a seasoned Fullstack (Java + React) developer to work on a fast-growing internal project processing large volumes of financial data.

You will build features with Java, Spring Boot and React, and support production systems while collaborating with an international team. Hybrid work in Warsaw, English proficiency required, and experience with Agile teams is essential.

Qualifications

• 5+ years of commercial experience with Java, including Spring Boot.
• 5+ years of experience with React.
• Experience with Docker and SQL; large databases experience is a plus.
• Experience working in Agile teams.
• English at B2+/C1 level; readiness for hybrid work in Warsaw.

Responsibilities

• Develop a new application processing very large volumes of financial data using Java, Spring Boot and React.
• Implement business modules for the investment fund market, including settlements and reconciliations.
• Maintain and support live production systems with incident handling and user support.

Skills

Java

React

Tools

Docker

SQL

Job description

What you work on today shapes where you'll be tomorrow.

Looking for your next challenge as a Fullstack (Java + React)? We may have the right opportunity for you.

At B3, we start with people and their experience. We match projects to your skills and professional growth path. Our consultants work across a wide range of industries and technologies, delivering IT projects both in Poland and internationally. This allows you to build your career in a deliberate way - not by chance.

We are part of an international organization listed on Nasdaq Stockholm, operating in 11 countries. In Poland, we operate with full autonomy. We choose our technologies, processes, and ways of working while maintaining the highest professional standards.

Join us today.

What we offer

• Work in a Scandinavian culture built on logic, trust, and open dialogue.

• Health and sports benefits tailored to your needs.

• Speed Coaching - short sessions designed to provide new perspectives and solutions.

• Sports training, an internal team, and opportunities to take part in competitions.

Areas of responsibility:

• Developing a new application processing very large volumes of financial data - building features with Java, Spring Boot and React in a fast-growing internal project

• Implementing business modules for the investment fund market - handling ETF funds, edge cases such as settlement fees, and payment reconciliation processes

• Working on both new feature development and maintenance of a live production system - incident handling and support for active users, in self-contained tasks that do not require knowledge of the entire architecture upfront

What you need to join us:

Must have:

• 5+ years of commercial experience with Java, including building applications with Spring Boot

• 5+ years of experience working with React

• Experience with Docker and hands-on knowledge of SQL and working with large databases

• Experience working in Agile teams

• English at B2+/C1 level as the main language of daily collaboration, and readiness for hybrid work in Warsaw (1-2 days per week)

• Eligibility to work in Poland (citizenship, residence card, visa, etc.)

Nice to have:

• Experience in the financial domain - investment funds, ETFs, settlements, reconciliation processes

• Experience in projects with large data volumes and high performance requirements

• Experience collaborating with a distributed, international team and business stakeholders

• Experience combining production system maintenance with new feature development