Senior Java Developer

OPTIVEUM sp. z o.o.; Warszawa; Hybrid; PLN 124,000 - 207,000; Full time

Benefits offered by this job

B2B contract

Hybrid work model

International environment

Supportive culture

Job summary

OPTIVEUM sp. z o.o. is seeking a Senior Java Developer in Poland for hybrid work (Warsaw, Gdańsk, or Gdynia). You will design, implement, and maintain Java applications for tax, accounts, and investment processing on pension products.

Strong Java 21 skills with Spring Boot, Hibernate, and PostgreSQL are required, along with JMS/MQ, OpenAPI/AsyncAPI, Git, and CI/CD. You will mentor others and help drive engineering best practices in a multinational environment.

Qualifications

• Strong proficiency in Java 21 and Spring framework stack.
• Experience with PostgreSQL and messaging (JMS, MQ).
• Knowledge of OpenAPI/AsyncAPI for data contracts and integration.
• Git and CI/CD pipelines; solid OOP and design patterns.
• Advanced English for international collaboration.

Responsibilities

• Develop and maintain Java applications for tax, accounts and investments.
• Build robust calculation engines across multiple countries.
• Integrate with tax authorities and generate reports for customers.
• Contribute to full SDLC and mentor peers.
• Apply AI-assisted tools to improve productivity and quality.

Skills

Java

Spring

Spring Boot

Hibernate

PostgreSQL

JMS

MQ

OpenAPI

AsyncAPI

Git

CI/CD

OOP

Advanced English

Tools

OpenAPI

AsyncAPI

Job description

Senior Java Developer

Rate: Up to 150 PLN/h net + VAT (B2B)

Location: Warsaw, Gdańsk, or Gdynia

Work Model: Hybrid (3 days a week from the office / 50% remote)

We are Optiveum, a specialized recruitment and contracting company. We are currently looking for a Senior Java Developer to join the team of our client, a prominent international company operating in the financial and investment sector.

In this model, you will sign a B2B cooperation agreement directly with Optiveum.

As a Senior Java Developer, you will be responsible for developing and enhancing our client's Java-based applications that handle taxation, account management, and investment processing for pension and savings products.

Key Responsibilities

• Designing, developing, and maintaining Java applications supporting savings and investment products.


• Building robust calculation engines that ensure compliance with current tax regulations across multiple countries.


• Developing support for complex business processes, integrating with tax authorities, and generating customer-facing reports.


• Participating in the full software development lifecycle, including requirements analysis, design, coding, testing, and deployment.


• Collaborating with financial analysts to translate business requirements into technical solutions.


• Mentoring other developers, acting as a code reviewer or design sparring partner, and spreading practical engineering practices across the team.


• Responsibly utilizing AI-assisted development and automation tools to improve productivity, quality, and continuous learning.

Must-Have Requirements

• Strong proficiency in Java (especially Java 21) and related frameworks (Spring, Spring Boot, Hibernate).


• Experience with relational databases and SQL (e.g., PostgreSQL).


• Knowledge of messaging protocols such as JMS, MQ, etc.


• Knowledge of OpenAPI and AsyncAPI for producing and consuming data.


• Familiarity with version control systems (Git) and CI/CD pipelines.


• Solid understanding of software design patterns and Object-Oriented Programming (OOP) principles.


• Advanced English proficiency, allowing for smooth communication in an international environment.

What Optiveum Offers

• A transparent B2B contract signed directly with Optiveum as your contracting party.


• Attractive hourly rate up to 150 PLN/h net + VAT.


• Ongoing operational support from Optiveum throughout the entire duration of our cooperation.


• The opportunity to work in a collaborative, international environment strongly influenced by a supportive Swedish organizational culture.


• A flexible hybrid working model.