Java Developer

Solid Company; Kraków; Hybrid; PLN 120,000 - 180,000; Full time

Job summary

Solid Company in Kraków is seeking a senior Java developer to join the team building Flight Plan Manager, a sophisticated flight planning solution used by major airlines. You will design and implement new features within a Scrum team and ensure code quality through automated tests.

The platform supports on-premises and SaaS deployment, uses Spring, Hibernate, microservices, and modern DevOps practices. Fluency in English and Polish is expected.

Qualifications

• 5+ years of professional Java development experience.
• Strong knowledge of Spring and Hibernate.
• Understanding of microservices architecture.
• Experience with API design and SQL databases.
• Knowledge of SOLID principles and design practices.
• Experience with Git and Docker.
• Familiar with Scrum or Kanban methodologies.
• Fluent in English and Polish.

Responsibilities

• Design, develop, and estimate new product features within a Scrum team.
• Develop automated tests and apply Test-Driven Development (TDD) practices.
• Maintain and refactor complex codebases, including legacy systems.
• Apply SOLID principles and software engineering best practices.
• Debug applications, analyse performance, and resolve functional and non-functional issues.
• Participate in code reviews and technical documentation.
• Collaborate with distributed engineering teams and demonstrate solutions to internal and external customers.

Skills

Java

Spring

Hibernate

Microservices

API design

SQL databases

SOLID principles

Git

Docker

Scrum/Kanban

English

Polish

Analytical thinking

Job description

Project

Join the team developing Flight Plan Manager, an advanced flight planning solution used by over 30 customers, including major international airlines.

The product optimises flight routes, altitude, speed, and timing while considering fuel costs, CO₂ emissions, weather conditions, airspace restrictions, and delays. It is available as both an on-premises solution and a SaaS platform.

You will

• Design, develop, and estimate new product features within a Scrum team
• Develop automated tests and apply Test-Driven Development (TDD) practices
• Maintain and refactor complex codebases, including legacy systems
• Apply SOLID principles and software engineering best practices
• Debug applications, analyse performance, and resolve functional and non-functional issues
• Participate in code reviews and technical documentation
• Collaborate with distributed engineering teams and demonstrate solutions to internal and external customers

Kogo poszukujemy?

Must have

• 5+ years of professional Java development experience
• Strong knowledge of Spring and Hibernate
• Understanding of microservices architecture and design patterns
• Experience with API design and SQL databases
• Knowledge of algorithms, SOLID principles, and software design practices
• Experience with Git and Docker
• Understanding of the software development lifecycle and Scrum or Kanban methodologies
• Strong analytical and problem-solving skills
• Fluent in English and Polish

Nice to have

• Experience with Kafka, ActiveMQ, or IBM WebSphere MQ
• Frontend development knowledge, particularly React and TypeScript
• PowerShell or other scripting languages
• Experience with Jira or similar tracking tools
• Familiarity with observability tools and practices, including monitoring, logging, and tracing
• Experience with AWS and Kubernetes
• Experience with LLM-assisted coding tools, including agent and instruction files