Software Developer Backend (mf/d) Java/Kotlin, Spring Boot

etalytics; Darmstadt; Hybrid; EUR 60,000 - 80,000; Full time

Benefits offered by this job

Hybrid work with home office options

Flexible working hours

Team events

30 days vacation

Tax-free benefits card

Gym membership subsidy

Job bike

Job summary

etalytics seeks a Backend Software Developer to own backend services for our etaONE platform. You will build scalable REST APIs using Java or Kotlin and Spring Boot, and work with Product Owners, Frontend Developers, Data Scientists to translate requirements into robust solutions.

You will contribute to testing, code reviews, and maintainable code, while growing your technical expertise. The role offers hybrid work in Darmstadt, with language flexibility in English and German as a plus.

Qualifications

• 2+ years of backend development experience.
• Strong Java or Kotlin and Spring Boot knowledge.
• Experience designing and integrating REST APIs.
• Proficient with PostgreSQL databases.
• Experience with automated testing, Git, and code reviews.
• Ability to structure complex tasks independently and deliver maintainable solutions.
• Use of AI tools to improve development processes.
• Fluent English; German knowledge is a plus.

Responsibilities

• Develop and enhance backend services and REST APIs for our etaONE platform.
• Own complex features from concept through production readiness.
• Collaborate with Product Owners, Frontend Developers, Data Scientists, and other stakeholders.
• Ensure high software quality through automated tests and clean code reviews.
• Analyze and improve existing services for maintainability, performance and scalability.
• Approach debugging systematically and drive sustainable solutions.
• Share knowledge with the team and mentor less experienced colleagues.
• Leverage AI tools to drive development efficiency.

Skills

Backend development

Java or Kotlin

Spring Boot

REST APIs

PostgreSQL

Automated testing

Git

Code reviews

English fluent

German knowledge

Tools

Spring Framework

PostgreSQL

Job description

Do you want to build software that makes a measurable impact on energy efficiency and sustainability?

At etalytics, we develop AI-powered energy management solutions that help industrial companies reduce energy consumption, CO₂ emissions, and operating costs. As a Backend Software Developer, you will take ownership of backend services and features for our etaONE® platform.

You will contribute your ideas to technical decisions, and continuously improve the scalability, maintainability, and quality of our software. At the same time, you will have room to grow your technical expertise and responsibilities.

Tasks

• Develop and enhance backend services and REST APIs for our etaONE® platform using Java, Kotlin, and Spring Boot.
• Take ownership of more complex features, from technical concept through to production-ready implementation.
• Work closely with Product Owners, Frontend Developers, Data Scientists, and other stakeholders to translate requirements into robust technical solutions.
• Ensure high software quality through automated testing, code reviews, and clean code principles.
• Analyze and improve existing services with a focus on maintainability, performance, and scalability.
• Approach debugging and root-cause analysis in a structured way and help the team implement sustainable solutions.
• Share your knowledge with the team and support less experienced colleagues with technical questions.

Requirements

• You bring a minimum of 2 years of hands-on experience in backend development
• Strong knowledge of Java or Kotlin and practical experience with Spring or Spring Boot
• You are confident in designing, developing, and integrating REST APIs.
• Experience with relational databases such as PostgreSQL allows you to independently develop data models and database queries.
• Automated testing, Git, code reviews, and clean code principles are part of your professional development workflow.
• You structure complex technical tasks independently and develop pragmatic, maintainable solutions.
• Use our AI tools to drive and improve your development.
• Fluent English skills enable you to work confidently in our international environment, German Knowledge is a Plus.

Benefits

• Purpose-driven work: Support industrial companies in becoming more efficient and sustainable
• Flexibility: Hybrid working with home office options and flexible working hours
• Team spirit: A supportive, collaborative environment with plenty of room for exchange and cooperation
• Community: Regular team events and shared activities
• Work-life balance: 30 days of vacation plus a flexible, agile work culture
• Well-being: Tax-free benefits card, subsidized local gym membership and the option of a job bike