Co-founder reached out to me on linkedIn
6 rounds

1. OA - 2 LC mediums
2. DSA round - LC medium Tree questions with followups on optimsation
3. LLD - bunch of small questions on SOLID principles, debugging, databases and general engineering
4. HLD - Design a Ad broking service that works in real time
5. Take home assignment - Write a Newsletter service that acts as a message broker and sends emails to registered users, Deploy the APIs on heroku, time given 2 days
6. HM round - What persona does , why i want to join persona, comp discussion

Hm told me design skills were not upto mark and they will give me SE and not SSE
Overall the engineers were good and the interview process was good and interactive as well.
https://leetcode.com/discuss/compensation/5502665/Multiple-Offersor-EightFold.ai-or-observe.ai-or-postman-or-avalara-or-persona-or-diamanti