Senior Java Developer (K/M)

We are looking for experienced Java Developers who want to grow their skills and work on interesting projects in the retail and sales technology area.
You will be joining a team working on POS and BackOffice solutions supporting sales, store operations, integrations, reporting, payments, fiscalisation, and other retail-related processes.

Your responsibilities
• Designing and developing efficient, scalable, and stable software.
• Participating in the design and implementation of new features.
• Supporting technical decision-making and selecting appropriate technologies and implementation approaches.
• Working on the optimisation of the software development process.
• Analysing technical requirements and proposing practical, maintainable solutions.
• Supporting integration design between POS, BackOffice, payment systems, fiscal devices, external platforms, and other retail systems.
• Taking ownership of complex technical topics and supporting the team in solving architectural or implementation challenges.
• Cooperating with developers, analysts, testers, product owners, and other stakeholders.
• Reviewing code and supporting good engineering practices within the team.

Our requirements
• At least 5 years of commercial experience in IT.
• Very good knowledge of Java.
• Experience with Spring Boot, Spring Cloud, JPA, and SQL.
• Good understanding of backend application design and system integration.
• Experience in designing stable, maintainable, and scalable solutions.
• Ability to analyse business and technical requirements and translate them into clean technical solutions.
• Experience with relational databases and query optimisation.
• Practical knowledge of Git-based version control.
• English at B2 level or higher.
• Ability to write, understand, review, and maintain code independently, without relying on LLM-based tools - we do allow and encourage you use all kinds of tools, including AI, but we expect you to have a deep understanding of the results
• Good communication skills and the ability to work in a team.
• Responsibility for delivered solutions and a proactive approach to problem-solving.

Nice to have
• Experience as a Tech Lead, Lead Developer, or Solution Architect.
• Experience in making or supporting architectural decisions.
• Experience with POS, retail, payments, fiscalisation, or enterprise sales systems.
• Experience with desktop applications or applications running in store environments.
• Knowledge of multithreading, performance optimisation, and offline-first systems.
• Awareness of web technologies
• Experience with CI/CD, GitLab pipelines, automated testing, or deployment processes.

Technologies we use
POS
• Java
• Multithreading
• Plain JDBC
• Web client used in integrations
• Swing for UI
• SQLite embedded database

BackOffice
• Java 21
• Spring JDBC
• Tomcat as a web application container
• Apache Wicket
• PostgreSQL
• JasperReports
• Karate

We offer:
• Employment in a reputable organization (ITwiz BEST100), operating in accordance with international quality and security standards (ISO 9001, ISO 27001)
• A non-corporate atmosphere and a flat organizational structure
• Opportunities for continuous development through:• working with a variety of technologies on projects for well-known clients
• collaboration with an experienced team of experts who are eager to share their knowledge
• co-financing of training and certifications

• Employee Referral Program
• Participation in charitable initiatives, including cooperation with the Joanna Radziwiłł Foundation “Opiekuńcze Skrzydła” and involvement in the “Gwiazdorzymy” holiday campaign
• Private healthcare (LUX MED), 50% co-financing of the Multisport card, co-financing of foreign language learning, and access to a wellbeing platform.
• A diverse and inclusive work environment – our company brings together representatives of four generations
• Equal development opportunities – 50% of managerial and leadership positions are held by women
• Organizational culture based on values:
• we act with good intentions
• we share knowledge
• we take responsibility
• we continuously improve people are our top priority
• we act with a clear sense of purpose and meaning
• we communicate honestly and professionally