The interviews was fine, but the challenged was really hard and unrealistic for a front-end position. It was a totaly algorithmy based challeng with 4 complex algorithyms to be done in only 1 hour. There was no tests related to important areas on front-end development like HTML/CSS, framework-specific tests and others. And all of that should be done in a system which is pretty hard to use and debug. I made other front-end challenges for different companies through hacker-rank and i got a flawless score... For FullStack Labs i got a bad score and then, my hiring process was discontinued... So, an interview that started really good, ended up in a very frustrating experience due to a misguided challenge. This kind of process wil made progress for full-stack developers which have solid experience in backend and deep data-analysis programming... But will certain miss good front-end specialists.