Senior Java Developer (Freelance)

Quick Facts

• Role: Senior Java Developer (Freelance)

• Location: Poland (Hybrid: 1–2 days/month in Warsaw)

• Working hours: CET

• Start date: around 09.11.2026

• Duration: 3–6 months

• Rate: up to 160 PLN/h

Description

Freelance Senior Java Developer role for projects in Poland with flexible working arrangements and CET working hours. You will design and build backend services using Java and Spring Boot, integrating data pipelines, REST APIs, and Kafka-based messaging. Assignment expected to run for 3–6 months starting around 09.11.2026.

Responsibilities

• Develop and maintain backend features using Java and Spring Boot

• Work with Hibernate/JPA and SQL for data access

• Build and maintain data pipelines and data mappings

• Implement REST APIs

• Integrate and work with Kafka topics (Kafka/Debezium)

Requirements

• Fluent Polish

• English proficiency sufficient to read technical documentation, handle business correspondence, and communicate verbally with international vendors

• At least 4 years of software developer experience

• Knowledge of Java, Spring Boot, Hibernate/JPA, SQL, JUnit, Kafka

• Solid knowledge of design patterns and object-oriented programming principles

• Knowledge of Azure cloud services

• Ability to work with data mappings

• Knowledge of JSON data format

• Building data pipelines

• Ability to work with REST APIs

• Knowledge of creating topics (Kafka/Debezium)

Benefits

• Flexible work

• Work with an experienced team of developers and continuous development of your hard and soft skills

• Dev-friendly processes such as Continuous Integration, Continuous Delivery, Code Review, and bug bashes

• Long-term collaboration on challenging products (FinTech, B2B software, E-commerce, and more)