Backend Engineer – Energy Optimization PlatformVerified as a real position

Who we’re looking for

• min 4 years of backend development experience in Python.
• Strong grasp of OOP and clean code practices.
• Experience building REST APIs (FastAPI would be ideal).
• Experience designing system architecture and microservices.
• Confidence working with SQL databases and Linux environments.
• A healthy obsession with testing and code quality.
• 2–4 years of professional software development experience.
• Strong Python programming skills with OOP principles.
• Experience building REST APIs using FastAPI.
• SQL database experience.
• Strong unit testing skills.

What you’ll do

• Designing and building reliable backend services and RESTful APIs using Python and FastAPI.
• Collaborating on a tool for optimizing energy systems, batteries, and renewables — yes, the kind that help fight climate change.
• Helping shape and evolve our system architecture (microservices), including proposing a concept for the next stages of product development.
• Reviewing code, writing tests, and generally making the codebase a better place.
• Helping maintain our CI/CD pipelines, Dockerized environments, and cloud infrastructure (AWS).
• Design, develop, and maintain scalable backend services and APIs using Python and FastAPI.
• Contribute to building and evolving a tool for smart management and optimization of energy systems, batteries, and renewables.
• Help define, evolve, and scale our system architecture and microservices.
• Participate in code reviews, testing, and debugging.
• Contribute to CI/CD pipelines and infrastructure management.

About the position

We’re looking for a backend developer to join the engineering team behind our Optimization Engine — a core product that does the smart management of batteries, renewables, and energy systems to cut costs and carbon. If writing clean, scalable APIs and wrangling real-world data sounds like your kind of thing, let’s talk. Wattstor is a next-generation energy company accelerating Europe’s transition to net zero. We specialise in delivering renewable energy systems, on-site energy optimisation, and dynamic tariffs for businesses across the continent. Our mission is to make sustainable technology not only accessible but also simple and impactful. Backed by years of R&D and real-world deployment, Wattstor’s smart energy solutions are fast to implement, easy to manage, and built to reduce both costs and carbon emissions.

Benefits

• Motivating salary package.
• Quarterly bonuses & Sales Commissions
• Exciting Industry Sector which is full of innovations
• Professional growth, educational support and team growth opportunities
• 25 days of vacation and 5 sick days.
• Human-centric approach and team support.
• Opportunity for international training.
• Flexible, hybrid working hours (offices in Brno, Brumov-Bylnice and home office).
• Meal and phone allowance.
• Company events (Czech and Great Britain colleagues)
• Multisport card, fruit days