I applied through an employee referral. The process took 2 weeks. I interviewed at Klaviyo (Boston, MA)
Interview
First I completely a moderately difficult email architecture project that was to be turned in. That was approved and I was then moved to a phone screen and finally an in person interview. The in person interview crossed many departments, first with HR, then was brought to lunch by a few engineers. After wards I met with the VP of Engineering and a few more engineers.
HR asked clarifying questions about Klaviyo, how career development works and why I would want to work there.
The Lunch interview was definitely an engineering culture interview which went nicely.
The interview with the VP of Engineering was reasonably tough asking about my current company's API architecture which I did my best to explain but admittedly could not describe to a finite technical degree.
Finally the last interview was a collaborative coding exercise where I was to refactor a snippet of Python code to be more efficient and easier to read whilst explaining my thinking to the other engineers.
Throughout the interview I could tell there was a deep focus on general DevOps knowledge of deploy processes and large scale data processing as a focus.
Interview questions [3]
Question 1
What is the most challenging project you worked on?
Given the collaborative Python exercise, how would you manage this as a server? What tools would you use as the sole owner of this new software? How do you handle server errors and how will you determine when the server is down?
HR screening. Asked me some questions about software basics and sent me a code signal link. Asked about how I utilized AI in day to day work and how much design work versus coding task
ICF Codesignal, recruiter screen, and then final interview. Codesignal was easy as long as you prepped for it, there are many examples of ICFs online. Recruiter screen was normal. Final interview was not DSA related. Mostly related to the real experience of being a swe.
I applied online. I interviewed at Klaviyo (London, England) in Mar 2026
Interview
The interview process was generally well structured. I had an initial 30-minute recruiter call, followed by an assessment task and a hiring manager interview. The final stage consisted of three separate one-hour interviews covering different skill areas, with two interviewers in each session. One focused on frontend skills, while the others leaned more toward backend and broader technical competencies. Overall, the experience was positive, though having a three-hour final stage in a single day felt quite intensive.
Interview questions [1]
Question 1
Do a code review and fix what might be wrong or how you would fix it.