Turning AI into impact: 2x faster software delivery at PostNL

Develop faster, while maintaining quality

The mail domain is complex, business-critical, and constantly evolving. At the same time, volumes are declining, while the need to realize new functionalities faster and manage existing systems efficiently is growing. This calls for innovation.

PostNL and Sogeti share the ambition to use technology smartly to deliver value faster. AI offers great opportunities, but also raises important questions. How do you guarantee quality and security? And how do you prevent AI from becoming a black box detached from the craftsmanship of developers?

AI as an integral part of developer tooling

Multiple DevOps teams are active within PostNL’s mail landscape, including the Sorting Team, which focuses on the logistical core: everything needed to efficiently sort mail flows and prepare them for delivery. Within PostNL, this team is at the forefront of the adoption of AI in software development.

The team uses GitHub Copilot and its agents as constant support in development. Where possible, the team works with so-called spec files, which define what a feature must do – for example, the operation of a new chat window in an application. Think of behavior, interaction, and design. Based on this specification, AI then generates the corresponding code. The spec file, rather than the code is managed as the ‘source of truth’. As a result, changes are easy to implement, and developers just need to adjust the specification and regenerate. This way of working – also known as enterprise vibe coding – ensures greater flexibility and speed in the development process.

Greater speed and continuously high productivity

The impact is clear. Development speed has increased, and since the deployment of Copilot agents, the number of pull requests has doubled. This does not automatically mean that “twice as much work” is being done, but it does mean that lead times are shorter and teams are working more efficiently. Through this way of working, the team aims to further standardize applications and simplify the IT landscape. Less complexity means simpler management, faster further development, and more room for innovation.

AI and craftsmanship reinforce each other

The power lies not in AI alone, but in combination with craftsmanship. AI accelerates, but humans determine the direction. This allows for faster software development while simultaneously increasing quality. Together with PostNL, Sogeti demonstrates how innovation works in practice: step by step, with an eye for people, technology, and business value.