Java Backend Engineer for Tax & Investment Platforms

b2bnetwork; Warszawa; On-site; PLN 180,000 - 280,000; Full time

Job summary

b2bnetwork is seeking a senior Java backend developer to design, develop and maintain Java applications for our pension and savings products. You will work on tax calculations and investment processing across multiple countries.

You will participate in the full SDLC, mentor peers, and apply OpenAPI/AsyncAPI knowledge, SQL with PostgreSQL, and CI/CD pipelines. Collaboration with financial analysts and a strong emphasis on quality and responsible AI-assisted development are key.

Qualifications

• Must-have Java 21 and Spring Boot experience.
• Proficient with PostgreSQL and relational databases.
• Familiarity with messaging protocols (JMS, MQ).
• Strong Java capabilities with Spring/Hibernate frameworks.

Responsibilities

• Design, develop, and maintain Java applications supporting our savings and investments products.
• Build robust calculation engines ensuring tax compliance across countries.
• Develop support for complex business processes, integrating with tax authorities and generating reports.
• Participate in full SDLC from requirements to deployment.
• Collaborate with financial analysts to translate requirements into technical solutions.
• Mentor other developers, perform code reviews, and promote engineering practices.
• Use AI-assisted development and automation to improve productivity and learning.
• Demonstrate strong collaboration and analytical skills.

Skills

Java 21

Spring Boot

PostgreSQL

Messaging (JMS/MQ)

Hibernate

OpenAPI/AsyncAPI

Git & CI/CD

Design patterns / OO

Collaboration

Job description

b2bnetwork is seeking a senior Java backend developer to design, develop and maintain Java applications for our pension and savings products. You will work on tax calculations and investment processing across multiple countries.

You will participate in the full SDLC, mentor peers, and apply OpenAPI/AsyncAPI knowledge, SQL with PostgreSQL, and CI/CD pipelines. Collaboration with financial analysts and a strong emphasis on quality and responsible AI-assisted development are key.