Interview process was very straightforward. Started with a phone screen with the recruiter to learn more about the position and the company and to make sure you're a good fit. Next was a timed take home assessment where you work on a real life type of assignment to prove your skills, it was not really a leetcode type of problem. And you also needed to complete 4 stages where the next one builds off your previous solution. Also, you do not need to complete the entire assessment in the timeframe to move on to the next stage of interviews. I was able to get it the final part of the assessment and I didn't complete every test case before running out of time, but was still moved on to the best round. Next was an interview with a hiring manager, when you figure on your background and do a deep dive into a project you've worked on and how you designed and implemented your solution. They're looking for lots of details here and will ask followup questions about how and why you implemented the project the way you did, how did scale, alerting and monitoring, single points of failures, what did you learn....etc. I recommend to chose a project where you were the lead engineer and were heavily involved in the implementation. Next was the final round interviews. The first interview was a live coding collaboration with a couple Klaviyo devs where you're given a project that was already implemented by someone else and you need to walk through the code and talk about how you would improve the code. They're really looking for how you work and collaborate with other devs and that you can spot bad code and improve it. Next was yet another hiring manager interview very similar to the one you did previously, the difference here was that this hiring manager may actually be the one hiring for the role you're applying for and in my case would be my eventual manager. Again, they dona deep dive on a previous project you've worked on. You can pick the same one you discussed in the first HM interview. Be sure to also come prepared with your own questions about the Klaviyo and how this HM approaches management as this person may be your future boss. Next was a system design interview with a Lead engineer and another Senior dev. In this interview you're given an existing system design diagram and prompt on how you'd improve upon it. So you're not building something from scratch, just building upon an existing system. This was also just a discussion with the devs, and I did not need to draw anything out. For this one, just study and prep for a regular system design interview, there are plenty of resources out there. Lastly, you interview with and engineering leader at Klaviyo to discuss your leadership skills. Lots of the classic "tell me a time when..." type of questions. Overall, although the process was 6 different interviews it was very engaging and you did feel like they were making sure that you'd be a good fit for the company and that your skills would transfer over. Also, my recruiter was the best recruiter I've ever worked with. Very involved in helping you succeed. He even did a prep call before your final round interviews where he goes over exactly what to expect for each interview. This was immensely helpful in preparing.