Being able to set up shared developer environments with question templates. The usability of the editor experience. Wide variety of coding languages to pick from.

Simple UI, huge library of questions and practical tasks, easy to customize, good report and skills customization. Report via email in pdf. Cool support team and managers!

There isn't a steep learning curve. As a hiring manager, I appreciate quickly getting where I need to go, renaming the instance and selecting a language. The session is saved for future reference; everything is easy and automatic. I am an engineer and a manager. I have custom platforms for every single continent for admin, pay, performance, recruiting flow etc.. But I only use one live coding platform. It does everything I want and quietly grows (newly added django!) without cluttering on the critical path. Being great while unobtrusively offering more is an art form we should all strive for.