Having custom hardware in testing laboratory can simplify many tasks, but sharply increases difficulty of initial setup. Does lab software have to force specific set of hardware, or should it be compliant with generic, off-the-shelf parts? During this talk Paweł will share benefits and consequences of both approaches. He will discuss API design decisions for testing laboratories focusing on SLAV test lab stack case. Presentation will cover lessons learned from shifting to user-centric perspective and possible outcome of such process.