Ready to develop software for renewable energy systems?

We have the job for you!

At Vela Solaris AG we are committed to making the planning of innovative energy systems simple and reliable! With our in-house developed software Polysun, we are world leaders in the digital simulation of energy systems for buildings. Renowned engineering companies, manufacturers and universities in over 40 countries rely on Polysun. Our customers realize efficient and sustainable solutions by cleverly linking all commercially available technologies – from PV, heat pumps, battery systems and energy management systems and many more. Based on the Polysun API, we enable our customers to create future-oriented web applications in the field of energy system simulation in the cloud.

To strengthen our software development team, we are filling a position as:

Senior Java API developer for renewable energy systems


Would you like to work on an innovative and digital energy future with your practical experience? Is it important to you to use your expertise for sustainable and meaningful solutions? Then we have an offer for you:

In the development department of Vela Solaris we are currently a team of three developers and are passionate about the idea of developing high quality, performant and robust software products. We focus on automating our lean development process following DevOps with CI/CD pipelines and automated quality assurance. We review each other’s code with pull requests and make time for architectural and technological discussions and make decisions by consensus. To achieve this goal, we rely on consciously chosen technologies.

Your tasks:

The further development of the RESTful Polysun API is one of your main tasks! Here you can optimally combine and contribute your skills in software engineering and your interest in renewable technologies.

  • Together with our development team you will work out the requirements for the architectural, technological and functional development of the Polysun API and implement them directly.
  • Due to your expertise in the area of API you are directly involved in customer projects and implement customer requirements.
  • You ensure the software quality in joint code reviews, unit and end2end tests, among other things.
  • In the operations area, you will work with the team to ensure that the Polysun API is available securely and reliably.

Your profile:

You are enthusiastic about developing professional software together with us and have several years of experience in software development with Java. You have extensive experience in the development of scalable SaaS applications with Java and you have experience with modern backend architectures.

Furthermore you bring the following knowledge:

  • Java Spring Framework (focus on Spring Boot)
  • Jersey
  • Relational and NoSQL databases
  • Container environments based on Docker like Kubernetes or OpenShift
  • AWS
  • Prometheus and Grafana (ideally also Grafana Loki)
  • Queue technologies such as Apache Kafka or RabbitMQ, for example
  • Linux / Unix

It is important to you to be part of a team and you are happy to share your knowledge and learn from others. You are fluent in German or English.

Our offer:

We make sure that you can develop to your full potential with us:

  • We take the time to train you on the job. We support you in your desire for continuous personal and professional growth.
  • You will constantly learn new things and take on extremely exciting tasks at the pulse of the future in the energy, IT and construction industries.
  • Freedom of design and creativity are important to us – we make sure that you get the necessary space for this.
  • With us you work in a modern working environment. You decide whether you want to use our central and friendly office spaces in Winterthur or work from your home office and also benefit from flexible working hours.
  • A top team is waiting for you. We support you with questions, are helpful and extremely competent.

Does our job offer appeal to you?

Then we look forward to getting to know you! Please send your application documents by e-mail to Angela Krainer, We will be in touch shortly!