Just got through the Snowflake behavioral round last week. Background: I'm a senior IC who got laid off earlier this year, been grinding interviews for a while. Writing this partly to process and partly because behavioral prep resources for Snowflake specifically are thin.
First thing to know: Snowflake has a defined set of company values and the behavioral round maps to them. The values they seem to care most about (based on what was asked): customer obsession, building on others' work (they call this something like humble collaboration), and moving fast without leaving a mess.
Actual questions I got or that were very close to what I got: "Tell me about a time you made a decision with incomplete data and it turned out to be wrong. What did you do next?" "Describe a situation where you had to push back on a stakeholder who was asking for the wrong thing. How did you handle it?" "Give me an example of when you saw a process that wasn't working and you fixed it without being asked." "Tell me about a time you had to collaborate with a team that worked very differently from you."
They use STAR format implicitly. You don't need to say "situation, task, action, result" but structuring your answer that way helps you stay on track. The interviewer I had took detailed notes and asked follow-ups on specifics: timelines, who specifically made the call, what the actual outcome measurement was.
What I messed up: I gave one answer that was vague about "the outcome" and she pushed back. I recovered but it cost me polish points. Prepare specific outcomes with numbers where you can. "The team shipped 2 weeks earlier" is better than "we ended up succeeding."
One thing that surprised me: she asked about a failure early in the conversation, not as a gotcha at the end. Be ready for it to come up first.
Haven't heard back yet. Fingers crossed.