The whole process was not smooth or pleasant. In short:
1. You can tell they know little about front-end if you have enough exp. Most of them are backend guys who only know Java until they are told to re-write using js a few months ago.
2. The 2nd round onsite will take you about 7.5 hours. I should be paid for this.
3. You will be asked multiple weird IQ questions from multiple interviewers. I have no idea why this is helpful for a front-end developer.
4. After the supposed feedback date passed, I waited extra 2 weeks, sent multiple emails to finally get a feedback. This almost effected my consideration a pending offer. This is far from smooth.