You are three months into a new team that owns infrastructure you have never worked with. What did your first 90 days look like, and what did you change?
What they are really testing: They want to see whether you can convert unfamiliarity into credibility on a schedule, and whether you know that the first fix should be small and earned rather than a grand redesign nobody asked for.
A real interview question
You are three months into a new team that owns infrastructure you have never worked with. What did your first 90 days look like, and what did you change?
What most people say
drag me
“I spent the first few months just learning the systems and getting up to speed, and after that I started picking up tickets like everyone else.”
It has no plan, no evidence of judgement about what to learn first, and no change at the end, so three months produced nothing the team could point at.
The follow-ups they ask next
How did you decide what NOT to change in the first 90 days?
Show restraint. Anything you cannot yet explain the history of, you leave alone, because the ugly thing is often load bearing.
What if your manager gave you no plan at all?
Say you would write the 90 day plan yourself and get it agreed, because an unstated bar is the real trap for a new joiner.
How did you avoid being an annoying question machine?
Batch questions, use scheduled pairing rather than constant interrupts, and always show what you already tried.
What the interviewer is listening for
- Agreed explicit success criteria with the manager up front
- Used on call and postmortems as the fastest map of what really breaks
- Earned trust with small unglamorous work before proposing change
- Backed the change with data, not opinion, and quantified the result
What sinks the answer
- Proposes a big rewrite in the first month
- Spent 90 days learning with nothing shipped
- Cannot name a single thing they improved
- Changed something they could not explain the history of
If you genuinely do not know
Say this instead of freezing. Reasoning out loud from what you do know beats silence every single time, and a good interviewer is listening for exactly that.
“I have not run a full 90 days on unfamiliar infrastructure yet, but here is how I would structure it: learn what actually breaks first, earn trust with small work, then change one thing with evidence. In my current role the closest version was ...”
Keep going with behavioural
Foundation
Tell me about a time you had to learn a new technology quickly. How did you go about it?
Foundation
So, why cloud? You have not worked in cloud before, so walk me through what actually pulled you here.
Foundation
Why are you leaving your current job?
Foundation
Tell me about a time you noticed something was broken, wasteful or risky, and nobody seemed to own it. What did you actually do?
Junior
You join a team and inherit a service with no documentation and the original author has left. Walk me through your first week.
Junior
Describe a time you were blocked and there was genuinely nobody available to ask. What did you do?
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