I applied online. I interviewed at Customer.io in Apr 2026
Interview
I applied through website and the whole process took me around 2.5 weeks and 2 interview rounds.
1. The HR interview was very smooth and pleasant, and I was moved to the next stage.
2. The interview with the Director of Engineering was more focused on my professional experience - the challenges I faced at previous companies, mistakes I made along the way and how I handled them, my approach to using AI, and similar topics.
Unfortunately, despite the fact that it went relatively well (or so it seemed to me 😁 ), I was informed that they are moving forward with other candidates.
But based on my research, I believe this is a great place to work, with a wonderful team and interesting challenges, especially for Frontend engineers.
Other Senior Frontend Engineer interview reviews for Customer.io
I applied online. The process took 3 weeks. I interviewed at Customer.io (New York, NY) in Feb 2021
Interview
About 4-5 interviews in total. The first is a chat with their HR lead, the second with the dev team lead, the third with the lead front end engineer, the fourth is a couple of front-end engineers to review your work. Supposedly the last one is an interview with the CEO.
Interview questions [1]
Question 1
How would you crunch a lot of numbers in a browser without locking up the UI?