I went through the Triplebyte interview last November. The first round was a quiz on their site, with ~40 programming questions on different languages, starting from something like 'find a bug in this bubble sort' to 'what would be the best way to design a system X'. The test wasn't difficult, most of the questions just tested the common sense and the basic programming skills. After the test there was a 2.5h Hangouts interview with one of the Triplebyte engineers. First, I was asked to write a code to implement a basic compression algorithm. I was allowed to use any resources I wanted, and I could use my own development environment. After the coding part there was a high-level web system design part, followed by some API design questions. The final part of the interview was a deep dive into a topic of my choice, where I just talked about my machine learning projects. The overall interview process was very well organized, and was focused on the real-world problems (not the typical whiteboard brain teasers I'm so annoyed with).