4hundred was born out of a dream. The dream of Andrew Mack and Ilona Ludewig to make the energy business honest and transparent to the end-user. It was a dream that investors were eager to take a bite of – but that first had to be proven by the market with an MVP.
The problem
The founders were fighting against time, as the European energy sector is highly competitive. They had the business plan and the initial capital to start the project but they didn’t have the technical team to start building it. To beat the clock, they had to work with a ready-made tech team. And Obecto and Zingasoft provided just that.
4hundred is Germany’s first digital-first energy provider and supplies renewable power to around 11 000 customers. Its business model is digital-first and based on honesty and transparency. Customers pay a monthly fee of 8 EUR that’s added to a community account that can be accessed anytime via their app. The account balance decreases with energy consumption.
The customer receives bonus credit for each day in which there is a surplus of money in the account – meaning that 4hundred actually tries to motivate people to spend less energy to the benefit of all.
The focus of the team was to build a service that’s easy to understand by domestic consumers – a stark difference from any electricity or gas bill we’ve seen before! And they wanted to match that with an effortless digital experience. That’s where our part comes in.
The solution
We were hired to develop the full MVP of 4hundred. The process took 9 months and helped the company push a product out quickly and efficiently without sacrificing quality.
The solution we developed had to cover a few key requirements. First, as a utility service, it had to be accessible and understandable by a large and diverse group of customers.
Additionally, the solution had to be integrated with a long list of third party systems, based on different technologies. These included payment providers, price comparison systems, contract transfer registries, and community energy systems.
We selected the tech stack to cover all of the points above, but also to easily scale and expand in different countries. It included:
- Microservices architecture with Azure Service Fabric
- Azure Web Apps
- Azure SQL Database
- Angular and TypeScript
- .NET Framework

In terms of project management and planning, the work got harder once the initial version of the product was live and in the hands of real customers. The team wanted to incorporate some great feedback we were receiving – which obviously leads to changing priorities and release scope.
We combatted that by relying on the agile mindset. Agile Scrum was the methodology we chose together with the client. 3 years into development, they even decided to hire a professional Agile Coach, to push them further into optimizing their process.
The results
With the support of Obecto and Zingasoft, 4hundred launched its MVP in line with the goal they had set – it took just 9 months.
Now, more than 11 000 end users are 4hundred customers, showing that honesty and transparency are key in the utilities sector.

We mentioned earlier that 4hundred were not just looking for an external provider – they needed a full tech team that they could rely on. In a sense, this means that the results for the client went well beyond the standard “usage and efficiency” metrics for a software solution.
Our technical team provided guidance and served as a full-scale partner, even attending business conferences in Germany with the 4hundred founders to answer technical questions from investors and accelerators. In this sense, the founders really did manage to hire a team, an extension to their core crew.
As Andrew Mack, founder of 4hundred and now CEO of Octopus Energy Germany put it:
“I wasn’t looking to outsource our technology development, I was looking to build the best team. And that’s exactly what working with Obecto and Zingasoft enabled us to do. Four years after starting to work together our relationship is still going strong, and we continue to innovate and build the business together.”
The biggest validation for 4hundred was the fact that Octopus Energy bought the company for 15 million pounds – a hefty offer showing the potential of the small independent team.