Transforming a legacy installer app into a trusted everyday tool for 6,000+ heating engineers.
Building confidence
Bosch has long been a trusted name in UK heating technology. Their installer app played a key role in supporting thousands of engineers, helping them register products, manage customer data and access technical support. But after seven years of patchwork updates, the app had become bloated and difficult to use. User journeys were unclear, internal knowledge was limited, and managing the platform had become a challenge.
To regain trust and modernise the experience, Bosch partnered with 383.
Untangling complexity
The app had grown out of shape. With six different user types, more than 170 features, and limited documentation, it was hard to navigate and even harder to maintain. Key actions like password resets returned vague errors. Engineers were frustrated. Internally, no one had a full view of how the system actually worked or what installers genuinely needed.
Strategic restructuring before rebuilding
Rather than jumping into fixes, we took a step back. Working closely with Bosch, we restructured the project from the ground up. Together, we created a clear backlog based on real installer needs, not legacy features. Our team reverse-engineered undocumented functionality, mapped out user journeys and documented every step to ensure transparency.
We simplified processes, cut unnecessary meetings and increased testing time to make sure what we delivered was robust and reliable.
Phased delivery focusing on core value first
The project moved ahead in two focused phases. Phase one delivered the essentials by September: secure login, product registration, customer management, guarantees, offline access and full app store deployment. This created a working MVP that solved key pain points.
Phase two added direct access to support tools, including boiler specs, technical documents and contact details, all within the app. Both phases aimed to reduce friction and rebuild confidence among installers.
Delivering measurable impact for users and business
The new app now supports over 6,000 installers with smoother, faster journeys and improved performance. Bosch has a clear product roadmap, a stable foundation and the confidence to keep evolving the platform. Installer satisfaction is up, guarantee registration drop-off is down, and engineers using the app are converting twice as many sales as those who don’t.
As a result, a once-bloated legacy product becomes an indispensable daily tool.
