Product-Minded Software Engineer (.NET/C#)

About Photoncycle

Photoncycle is reimagining the energy landscape by delivering energy as a service. We build, install, own, and operate distributed energy storage systems, together with the digital infrastructure needed to scale as an aggregator and electricity provider across European markets.

Our mission is to accelerate the transition to a more renewable, balanced, and secure energy system. Photoncycle systems combine solar energy, long-duration storage, and energy trading, so households can use homegrown energy year-round for electricity, heat, and hot water, while also helping the grid balance production and consumption peaks. This enables the transition away from fossil-based energy for households.

Our software platform is critical to that mission. It supports the digital services, fleet operations, and market capabilities required to operate Photoncycle systems safely, efficiently, and at scale.

We are 25 employees with offices in Oslo and Copenhagen. In 2026 we raised a €15 million Series A led by NordicNinja and Voima Ventures, and joined by Lifeline Ventures, Luminar Ventures, Momentum Partners, and Eviny Ventures. We are now moving from full-scale pilot to commercial rollout, and the first phase of our production plant is underway.

The Role

We are looking for a Product-Minded Software Engineer to help design and implement core backend software for Photoncycle’s next-generation energy platform. You’ll start by contributing to the team building our core energy platform software, and grow into adjacent product and business domains as the platform expands.

This role is primarily focused on backend development in C#/.NET. You’ll help build the software that represents, monitors, and interacts with deployed Photoncycle systems in the field, including telemetry, communication with units, operational health checks, and diagnostic data retrieval.

Much of this space is still unbuilt. You'll spend as much time prototyping, exploring, and testing ideas as shipping finished features. Enjoying the process of figuring out the right model before the answer is obvious is a core part of the job, not a detour from it.

As Photoncycle scales, you can also expect to contribute to broader platform capabilities such as fleet operations, customer and operator workflows, market-facing services, and integrations across the business.

This is a hands-on engineering role for a person, who is curious about the business, the users, and the operational reality behind the software. You don’t need to have it all figured out from day one; we value motivation, curiosity, holistic thinking, and the ability to connect what you're building to what the company and the customer actually need, not just the ticket in front of you. You will work closely with control system engineers, operations, product stakeholders, and other software developers to turn ambiguous real-world problems into reliable software.

Key Responsibilities

• Contribute to backend services for our core energy platform using C#/.NET.
• Build reliable telemetry, command, health-check, and diagnostic workflows for deployed Photoncycle units.
• Help model equipment state, configuration, and lifecycle as a foundation for future platform capabilities.
• Design clear domain models, APIs, and data flows that support operators, engineers, customers, and market-facing services.
• Contribute to adjacent platform domains as the product matures, including fleet operations, customer-facing services, market capabilities, and business integrations.
• Work with control system, operations, and product stakeholders to make pragmatic tradeoffs and validate features in real operational use.

What We’re Looking For

Must-have experience

• Backend development experience with C# and .NET.
• Experience designing and implementing production software with clear domain boundaries, robust data flows, and maintainable architecture.
• Experience working with relational databases and event-driven or message-based systems, for example Postgres and RabbitMQ.
• Ability to reason for reliability, observability, and failure modes in production.
• Product mindset: curiosity about the “why”, interest in business and user outcomes, and willingness to challenge or refine requirements.
• Comfortable working with stakeholders such as control system engineers, operations, and customer-facing teams.
• Ability to turn unclear operational needs into concrete, incremental software deliveries and equally comfortable exploring open-ended problems where the right answer isn't known yet.

Nice-to-have

• Experience with industrial systems, IoT, energy systems, telemetry platforms, or equipment monitoring.
• Experience with DDD, CQRS, event sourcing, modular monoliths, or event-driven integration.
• Exposure to software that interacts with physical assets or field-deployed devices.
• Experience with security-sensitive communication patterns, Zero-Trust networking, or authenticated device communication.
• Experience with Kubernetes.

We welcome applicants across experience levels, from motivated junior and mid-level engineers to more senior profiles. If you bring solid engineering fundamentals and genuine curiosity for this domain, we encourage you to apply even if you do not match every item above exactly.

What Success Looks Like for the Team You’ll Join

• Photoncycle has a reliable software foundation for understanding and operating deployed equipment, and a platform that can expand into adjacent business domains.
• Engineers and operators can see system state, investigate issues, and trigger safe actions with confidence.
• Telemetry, events, commands, and diagnostic workflows are modeled clearly and can scale with the fleet.
• The team makes better product and engineering decisions by bringing tradeoffs, data, and operational context into the discussion, and you’ll be part of making that happen.

What We Offer

• The opportunity to build foundational software for a high-impact climate technology company.
• A central role in shaping the software that connects Photoncycle’s physical systems, customers, operations, and market activities to its digital platform.
• A collaborative, mission-driven engineering culture with significant ownership.
• A conveniently-located office in Forskningsparken, easily reachable by T-bane, with strong amenities and social activities.
• A flexible work culture that encourages in-person collaboration, with one designated focus day per week for remote work.

Photoncycle is committed to building an inclusive workplace. We welcome applicants of all backgrounds and make hiring decisions based on skills, experience, and potential.