Turning a Legacy Trainer Interface into a Modern Product Foundation

The old interface was built in Delphi and had become difficult to maintain, difficult to extend, and increasingly disconnected from modern user expectations. It also reflected the wrong point of view: too much engineering logic was visible, while the real training experience was not central enough.

For a product sold globally, this mattered commercially. A trainer that looks understandable, polished, and modern is easier to sell than one that feels dated before the session even starts.

Instead of simply reskinning the old flows, the work started by looking at the real session: what the athlete needs to see, what the trainer needs during the session, and what information actually drives value during the workout.

That led to a simpler interface, clearer session flow, easier access to the most important actions, and less noise from low-level settings that had no business being central.

• Mode selection and start flow
• Session completion and stored statistics
• User login and identity
• UI-based settings instead of config-file editing
• Gamified feedback such as rankings and run results

Alternative C-based UI approaches were considered, but Unity provided the better overall fit. The simulator was already an interactive, game-adjacent product, and Unity allowed the team to unify interface logic and future content logic on one foundation.

That choice reduced future support complexity, improved staffing flexibility, and created a more extensible base than a narrowly optimized interface stack would have.

The key win was not choosing a prettier stack. It was choosing a stack that the product could keep growing on.

Under the touchscreen was a Windows machine talking to specialized hardware through a proprietary SDK. The documentation was thin and the integration ergonomics were poor.

The team not only made the integration work, but also documented it thoroughly enough that it became long-term reference material for later work. That turned a fragile dependency into a repeatable engineering base.

The simulator became easier to understand, easier to sell, and much easier to evolve. The product gained structured training data, a clearer user journey, and a software layer that could support future ecosystem work.

That later mattered enormously. Analytics, mobile identity, OTA updates, fleet tooling, and additional device experiences all became easier because the first major rewrite was done on the right rails.