CoreIntern

Interview Resources

Everything you need to walk into an interview prepared.

Behavioural Interviews

The round most people under-prepare for. Learn the answer format, work through the 30 questions that come up most often, and go in with questions of your own.

Answer in the STAR format
A structure for every “tell me about a time when…” question. It stops you rambling, and it is roughly what the interviewer is taking notes against.
SSituation

Set the scene in two sentences: the project, who was involved, and what made it hard. Any longer and you are burning your own airtime.

TTask

What you specifically were responsible for achieving. Say "I", not "we". The interviewer is scoring you, not your team.

AAction

The bulk of your answer. What you did, why you chose it, and what you ruled out. These are the repeatable behaviours the round is named after.

RResult

The outcome, with a number wherever you have one. "Cut cold starts from 4s to 900ms" lands; "improved performance" does not.

+RReflectionOptional

Optional, and the thing that reads as senior: what you took away, and what you would do differently if it happened again.

The 30 most common behavioural questions
Collated across top tech companies. Tap any question to see how to approach it.

No full-time experience yet? Internships, college projects, hackathons, club work and open-source contributions all count. Read “company” as “team” and “manager” as “lead or professor”. The interviewer is after the behaviour, not the job title.

Questions to ask the interviewer
Every round ends with “any questions for me?”, and “no, I’m good” is the wrong answer. Pick three before you walk in. Starred ones are the ones that land hardest.

The technical work

Ask an engineer these. They tell you what the day job is really like.

  • What are the engineering challenges the team is facing right now?
  • What has been the worst technical blunder in the recent past? How did you deal with it, and what changed afterwards?
  • What is the most costly technical decision made early on that the company is living with now?
  • What is the most technically complex project you have worked on here so far?
  • How do you evaluate new technologies, and who makes the final call?
  • How does the team balance feature work against maintenance and tech debt?
  • What does your stack look like, and what is the story behind choosing it?

The role itself

Worth asking the hiring manager, and useful for spotting a vague job spec.

  • What qualities do you look for when hiring for this role?
  • What would be the most important problem you would want me to solve if I joined?
  • What would I work on, and who would I work most closely with?
  • What does a typical day in this role look like?
  • I don't have much experience in this particular domain. How important is that to succeeding here?

Culture and working life

The honest answers here are the ones that surface red flags before you sign.

  • What is the most frustrating part about working here?
  • What is unique about working here that you have not experienced elsewhere?
  • What is something you wish were different about your job?
  • How is individual performance measured?
  • What does the company do to train and grow its engineers?
  • What is the policy on working from home or remotely?

The manager and the team

Save these for an engineering manager or a team-matching call.

  • How do you ramp up engineers who are new to the team?
  • What does success look like for your team this year?
  • What are the strengths and weaknesses of the current team, and what is being done about the weaknesses?
  • What is the team's biggest challenge right now?
  • How often are 1:1s, and what do they usually cover?
  • What is the current composition of the team, in seniority and size?

Company direction

Best asked of senior leadership, and especially useful at a startup.

  • How does the company decide what to work on next?
  • Who are your main competitors, and what differentiates you from them?
  • What are the highest priorities right now: new products, solidifying existing code, or reducing operations overhead?
How to prepare for a behavioural round
What actually moves the needle, in rough order of payoff.

1. Build 3-5 reusable stories, don't memorise 30 answers

Interviewers ask dozens of different questions, but strong candidates answer nearly all of them from a handful of deep projects. Pick three to five with real impact, real complexity and heavy involvement from you, and write out a STAR story for each. One good project usually covers conflict, ambiguity and communication all at once.

2. Prepare the Big Three cold

"Tell me about yourself", "tell me about your favourite project" and "tell me about a time you resolved a conflict" show up in almost every loop. These three are worth rehearsing until they are effortless.

3. Answer in the STAR format

Situation, Task, Action, Result. It keeps you from rambling and it is roughly the structure interviewers are taking notes against. Spend most of your time on the Action, and always close the Result.

4. Always have questions for the interviewer

Ending with "no, I'm good" reads as disinterest, and it is one of the easiest ways to lose an otherwise strong round. Bring three, and keep a spare in case the conversation has already covered them.

5. Research the company's values before the round

Most large companies score behavioural rounds against written values, and Amazon's Leadership Principles are the well-known example. Find them, and make sure you have a story ready for each of the big ones.

6. Write bullet points, not scripts

Memorised answers sound memorised. Note the beats of each story and practise saying them out loud: to a friend, to a mirror, or to an LLM prompted to ask you follow-up questions.

7. Send a short follow-up

A thank-you note within a day, referencing something specific you actually discussed, costs you nothing and is remembered surprisingly often.