Yup, I went through a similar experience with a YC startup no less. First round was a code review with the CTO/co-founder and it was a web API and SQL schema w

Yup, I went through a similar experience with a YC startup no less. First round was a code review with the CTO/co-founder and it was a web API and SQL schema with lots of little bits and varying "areas of interest" from data validation to exception handling (or lack thereof) to indices to type selection and other bits and pieces. Left a very strong and favorable impression on me for how much more enjoyable it was as a candidate and also how much more it felt like he presented a sandbox within which we could discover and discuss.