I did Instacart's behavioral rounds twice. Once in 2024 (didn't get the offer) and again earlier this year. Got the offer this time. Writing this partly to process it and partly because the behavioral round is really under-discussed for Instacart compared to the coding stuff.
First thing: Instacart's publicly stated values include things like customer obsession and collaborative execution. Their behavioral questions are very clearly mapped to these. Knowing their values doc before going in helped a lot on my second try.
Questions I got across both loops: Tell me about a time you had to push back on a stakeholder decision you thought was wrong. What happened? Describe a situation where you had to ship something you weren't proud of. What did you do after? Tell me about a project that failed. What was your role in that failure? Give me an example of working cross-functionally on something ambiguous. How did you drive alignment? When have you had to prioritize ruthlessly? What got cut and how did you make that call?
The last one came up in both loops in different forms. I think they care a lot about how you handle tradeoffs under constraint.
What changed between my two attempts: First time: my answers were fine structurally but I think I was too focused on what we built and not on what I personally did and decided. Second time I made sure every story had a clear moment where I made a call, not just 'we decided as a team.'
Also: they're fine with you taking 10-15 seconds to think before answering. Use that time. I used to rush and my stories came out jumbled.
The interviewers were genuinely warm, for what it's worth. It felt less interrogation-y than some of the bigger tech companies I've interviewed at recently.