DoorDash | Senior Engineer Details about Code Craft and System Design
Summary
For doordash, the code craft interview is a bit tricky and different. But luckily it has a small question bank and I think only 2 questions so I was able to practice both of those questions on a website. That helped a lot.
Full Experience
Coding Problem: Finding the nearest dasher to a location
I took a BFS approach from the start and the interviewer gave me the thumbs up to implement it. Follow-up: Return all equidistant closest locations
Discussed: Handling unreachable destinations Multi-source BFS optimization for repeated queries
Where I did well: Quickly identified BFS as the right approach and implemented cleanly Handled the follow-up extension smoothly
Result: All the test cases passed, interviewer seemed happy.
Code Craft Problem: Make a payment system for dashers.
Edge cases I tried to handle:
Overlapping delivery windows Multiple orders at different stages Time window boundaries Concurrent order limits Result: Interviewer seemed satisfied with the incremental approach and handling of edge cases.
I had practiced all the code craft problems here before so it was a lot easier for me.
System Design Problem: Review System with Voting
It's covered by this recently asked doordash design questions listed here: https://offerretriever.com/questions/31
Lukily I looked through and tried to practice all the design questions ahead of time, but sadly I didn't spend too long thinking about this one.
It went mostly ok, I choked a bit while talking about adding a cache, but we moved on from it and the rest went alright
Could have discussed more about sharding strategies for high-volume restaurants
Result: Feedback was mixed, felt I could have gone deeper on scalability ⚠️
Behavioral Standard behavioral round covering:
Past project experiences Conflict resolution scenarios Red flag screening questions (why leaving current role, team dynamics, etc.) Deep dive into a challenging project Pretty straightforward, no surprises here. The interviewer was friendly and conversational.
Result: Went smoothly ✅
Interview Questions (1)
Make a payment system for dashers.
Edge cases to handle
Overlapping delivery windows Multiple orders at different stages Time window boundaries Concurrent order limits
Preparation Tips
For system design, I should have prepared in-depth for all the recently asked system design questions. My questions was on that list but so sad I didn't prepare it well even though knowing it ahead of time
