Backend Developer

About The Company

KEOZ GmbH creates software by putting people, trust, and shared growth at the center of its work. As a software solutions partner and subsidiary of S-Markt & Mehrwert GmbH & Co. KG, KEOZ combines a strong focus on security with a passion for innovation. The company works openly and collaboratively, treating colleagues as partners and valuing diverse perspectives, practical problem-solving, and shared responsibility.

About The Company

KEOZ GmbH creates software by putting people, trust, and shared growth at the center of its work. As a software solutions partner and subsidiary of S-Markt & Mehrwert GmbH & Co. KG, KEOZ combines a strong focus on security with a passion for innovation. The company works openly and collaboratively, treating colleagues as partners and valuing diverse perspectives, practical problem-solving, and shared responsibility. Innovation, agility, and continuous development shape the way KEOZ works. Teams build customized software solutions designed to deliver meaningful value, while fostering an environment where people can grow professionally and contribute their ideas. At KEOZ, you will help shape both modern software and a workplace defined by humanity, camaraderie, and a forward-looking mindset.

About The Role

KEOZ GmbH is looking for a Backend Developer (m/f/d) to join its team in developing and enhancing modern backend services. In this role, you will work within a microservices architecture and contribute across the development lifecycle, from understanding requirements and designing solutions to testing, documentation, and ongoing improvement. You will collaborate with colleagues using agile and traditional development approaches, helping deliver services that are scalable, reliable, and maintainable. The position offers a permanent contract, a hybrid working model, and a flexible schedule. The advertised salary range is €60,000–€85,000, depending on experience and qualifications. Applicants should be comfortable working from the office twice a week and have excellent written and spoken German skills at native or bilingual level.

Qualifications

You bring solid professional experience in backend development with Node.js and have several years of experience building scalable services in a microservices environment. You have worked with Fastify or a comparable HTTP framework, TypeORM or a similar ORM, and relational databases such as PostgreSQL or MySQL. Experience with dependency injection is required; familiarity with Awilix is an advantage. You have practical experience applying test-driven development, preferably with Tap, and can plan and implement automated tests. You understand clean code and software design principles, and you make thoughtful decisions about quality, performance, and maintainability. Familiarity with agile and traditional development methods will help you contribute effectively. You are proactive, committed to high-quality work, and enjoy sharing knowledge and collaborating as part of a team.

Responsibilities

Develop, maintain, and enhance modern backend services within a microservices architecture. Translate requirements into reliable implementations, balancing quality, performance, and long-term maintainability. Plan, write, and automate test scenarios using a test-driven approach, and help ensure that services meet agreed standards before release. Document code, architecture, and workflows so that solutions remain understandable and supportable. Analyze technical issues, diagnose bugs, and implement effective fixes. Work closely with colleagues throughout development, applying the methods that best support each project. You will also identify opportunities to improve development processes and technical infrastructure, evaluating and applying modern technologies where they can deliver practical benefits.

Benefits

• Employees receive 30 days of vacation, access to individualized in-house physical therapy, and high-performance technical equipment.
• The company supports professional growth through personal development opportunities and continuing education, and encourages employees to contribute ideas and help improve how the team works.
• Additional benefits include a company pension plan or commuter pass, a Company Bike, team events, and company gatherings.
• The office provides a modern, ergonomic workspace, fresh fruit, sweet and savory snacks, soft drinks, and coffee.
• It is accessible by public transportation, with parking also available.

Equal Opportunity

KEOZ GmbH values diversity and is committed to a respectful, inclusive workplace where people can contribute, develop, and succeed. Applications are welcomed from qualified candidates with varied backgrounds and experiences. The company’s collaborative culture is built on openness, fairness, and recognizing the value each team member brings.