React Developer (m/f/d) in Cologne Startup

Do you want to be more than just a byte in the data sea? Do you want to passionately take responsibility in agile teams and actively contribute to driving the climate transition with us? Then we should definitely get to know each other!

About Us

As an agile, green startup and specialist for energy management and visualization software, we actively participate in shaping a sustainable, climate-neutral future. Our mission is to make energy consumption management so easy with intuitive, AI-driven software that it becomes a matter of course for everyone – whether businesses or private households – and effectively enables energy suppliers and corporate customers to reduce energy consumption and CO2 footprints. With our current 35 talented colleagues, we are making the digitalization of the energy industry a real opportunity.
Since 2025, we have been part of the Hausheld group: Together with Hausheld AG, Solandeo GmbH, and Mako365 GmbH, we form the first full-service platform for smart metering in Germany.

Responsibilities

OUR TECHNOLOGY STACK

• Kotlin, Spring, Java
• TypeScript, React, Redux, Recoil
• Jest, React Testing Library, Gauge & Taiko
• REST, OpenAPI
• SASS, CSS Modules
• Python, Pandas, NumPy
• IntelliJ IDEA, VS Code
• git, Maven, webpack
• GitOps, Gitlab CI, Argo CD
• PostgreSQL & TimescaleDB, MariaDB
• Jupyter Notebook
• Kubernetes, Helm, Kafka, Docker

As part of a motivated and innovative team, you will take care of the future of sustainable energy management. An excellent and sustainable product begins with a clear idea and vision. As a Software Developer, you will be involved in all steps of your product's lifecycle and, together with our product management and architects, you will refine the strategy of product development. High standards, precision, and critical questioning start for you even before coding.

YOUR RESPONSIBILITIES

• Together with the developer team, Product Owners, and UX/UI designers, you will drive the further development of our SaaS solutions (especially microservices)
• You will continuously design, test, maintain, and improve the software, both independently and within your team
• You will provide technical advice to product management and discuss functional and technical requirements and their implementation with them and the business departments
• In the DevOps area, you will increasingly take on co-responsibility for architecture, programming, and testing
• Through pair programming, code reviews, and prototyping, you will continuously develop not only our products but also yourself
• You will regularly exchange ideas with our agile and interdisciplinary teams within the framework of "DevComs" or our Architecture Board
• You will look beyond your own nose, realize your ideas in monthly GreenDays, and have the opportunity to contribute these ideas to product development

Qualifications

• You have successfully completed your studies in IT or have a comparable education that can convince us
• Furthermore, you already have initial experience as a Software Developer, ideally in the SaaS environment
• You have initial practical experience with microservices and cloud infrastructures
• You shine with extensive JavaScript/TypeScript knowledge, ideally in a React context. Alternatively, you score with very good Java or Kotlin know-how and have experience with SpringBoot
• You are familiar with the use and application of standard tools, especially in the agile environment, such as JIRA and Confluence for controlling and documenting development
• As a creative, analytical thinker, you enjoy new technologies and have a good sense of quality
• You live the startup mentality, are motivated, and enjoy tackling things directly
• You have good German and very good English skills

Benefits

• Intensive coaching and further training opportunities, as well as participation in DevCom and the Architecture Board
• A permanent, unlimited position with the opportunity to help shape the green startup scene
• Recognized as a "Top Company 2025" by kununu, with a startup atmosphere and plenty of room for creativity, flat hierarchies, and short communication paths
• Flexible working hours and, of course, the option to work from home
• Take Your GreenDay! Leave everyday life behind and dedicate one day a month entirely to your own ideas
• Regular team events (bouldering, board and online game nights, etc.) and daily foosball tournaments with ambitious colleagues aka foosball pros
• An office full of sprint memes and day-specific songs (e.g., Friday always ends with the playlist "Good Vibes")
• Weekly, transparent team meetings, supplemented with funny memes
• Inexhaustible coffee and water supplies, as well as regularly fresh fruit
• Location with excellent cultural, sporting, and transport connections

If you are attracted by the challenge of joining us on our mission, simply send us your CV and cover letter via the form.

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