Adobe CS1 Interview Experience (5.8 YOE Backend Engineer)
Background:
- 5.8 YOE backend engineer at a large investment bank
- 45 LPA CTC
This was my first interview after college. Recruiter reached out via Instahyre
R1 — DSA
Question:
- Longest Substring with At Most K Distinct Characters
https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters/
Interviewer joined late and directly jumped to the question. Standard sliding window problem, had solved it before so was able to code/explain it comfortably.
R2 — DSA + Project Discussion
Started with questions around my current project/work.
Coding question:
- Merge Intervals
https://leetcode.com/problems/merge-intervals/description/
Solved successfully. Both DSA rounds happened on Hackerrank on the same day.
R3 — Project Deep Dive + HLD (F2F Noida)
This round was heavily focused on past work:
- design decisions
- tradeoffs
- failure handling
- scaling
- concurrency scenarios
Then interviewer asked to design a URL Shortener.
Discussion included:
- unique short URL generation
- DB schema design
- what fields to store and why
- Redis caching
- cache eviction strategy
- scaling bottlenecks
One thing I noticed: interviewer cared much more about reasoning behind decisions than “perfect architecture”.
Overall this round went well and felt like a genuine engineering discussion.
R4 — Hiring Manager + HLD
Again started with deep discussion around my current project and architecture decisions.
Then came:
- “Design YouTube”
This was the toughest round for me. Since I had just started HLD prep, I honestly froze for a few seconds 😅
I started with basic architecture:
- videos in S3/object storage
- pre-signed upload/download URLs
- metadata in Postgres/DynamoDB
But interviewer quickly moved to harder parts:
- encoding/transcoding
- adaptive bitrate streaming
- CDN usage
- buffering optimization
- video compression
- handling huge video traffic efficiently
We discussed this for ~30 mins, but I lacked depth in my solution (he was from multi media domain so he went really deep into stuff). Round didn’t go well.
Biggest learning:
For senior backend interviews, interviewers focus a lot on the “hard parts” of distributed systems.
R5 — AI-driven LLD Round
This was a new AI-assisted round on Hackerrank.
Question:
- Design a Feature Flag Service
Requirements included:
- user/context-based rollouts
- app-version targeting
- conditional enable/disable logic, etc.
This round went badly for me.
I approached it like a normal LLD round by discussing entities/classes first. But the interviewer was evaluating:
- how effectively you use AI
- how quickly you iterate
- validating AI-generated output
- completeness of solution
I should have leveraged AI much earlier instead of trying to manually structure everything upfront.
Final Takeaways
- Know your current project extremely well — most discussions revolved around that
- For HLD, prepare beyond standard diagrams and focus on scaling bottlenecks/tradeoffs
- Interviewers challenge every design decision with “why?”
- AI-assisted interviews are becoming real, and require separate preparation
- Practicing only DSA is definitely not enough for senior backend roles
Overall a really good learning experience with a strong focus on practical engineering depth.
