I went through MongoDB's full interview loop last spring for a senior product role and did a lot of behavioral rounds. Sharing what I learned about how they approach the behavioral side, because it's more structured than it first appears.
MongoDB has a public set of company values they actually use to evaluate candidates. They call them things like "Think Big, Go Far" and "Build Together" and "Make it Matter." These aren't just wall art. The behavioral questions map directly to them. If you Google "MongoDB core values" you'll find the list. Print it out before your interviews and prep a STAR story for each one.
Questions I was actually asked: Tell me about a time you had to make a high-stakes decision with incomplete information. (Think Big) Describe a situation where you had to align a cross-functional team that had competing priorities. (Build Together) Walk me through a project where you changed direction mid-stream because the original goal turned out to be wrong. (Make it Matter) Tell me about a time you received critical feedback that was hard to hear. How did you respond? (this one isn't on a value card, it's more of a culture fit probe)
For PM/product roles there were also questions like: "How have you used data to overturn an assumption you had?" and "Describe how you've handled a situation where an engineer disagreed with your product decision."
What seemed to land well: specificity and actual numbers. Not "we increased retention" but "we reduced 30-day churn by 4 percentage points over two quarters." Also showing that you changed your mind due to evidence, not because someone pressured you.
What didn't land as well (feedback from recruiter post-offer): one of my stories was too focused on individual heroics and not enough on how I brought the team along. MongoDB really cares about collaborative wins. Edit your STAR stories to make sure "we" appears more than "I" in the action step.
Two behavioral rounds back to back in my loop. They do not share notes between interviewers beforehand (recruiter confirmed this), so you can use the same stories, but be ready to go deeper if they follow up differently.