Building Confidence for Technical Interviews

Building confidence for technical interviews usually starts with the advice to "just relax". Research suggests that is the wrong goal. Nerves before an interview are normal and come with energy you can use. What changes performance is how you interpret them and how well you have practised, not whether you feel calm.

Reframe nerves as excitement

In a series of experiments at Harvard Business School, people about to sing karaoke, speak in public or solve maths problems were told either to calm down or to say "I am excited". Most people believe calming down is the better strategy. But those who reappraised their anxiety as excitement felt more excited, took an opportunity mindset rather than a threat mindset, and performed better (Brooks, 2014).

A related study gave students preparing for the GRE a simple message: physical arousal before a test can improve performance. Those students scored higher than controls on a practice maths section, and higher on the maths section of their real GRE one to three months later (Jamieson et al., 2010).

The practical version for an interview: when your heart races before the call, do not fight it. Tell yourself, out loud if you can, "I'm excited; this energy helps me think." It takes seconds and the evidence says it helps.

Do not trust how you think it went

Data from interviewing.io, a platform for anonymous technical practice interviews, shows that candidates are poor judges of their own performance. Their sense of how they did explained only a small part of how interviewers actually rated them, with an R-squared around 0.24. People who thought they had done poorly were also three times less likely to want to work with their interviewer (interviewing.io: self-assessment).

Two lessons follow. First, a moment of struggle in an interview does not mean you failed it; interviewers often expect candidates to get stuck and value how you recover. Second, do not withdraw from a process or turn down a next round because you felt it went badly. Wait for the result.

Remember what is being assessed

Much interview anxiety comes from imagining the interviewer is waiting for a perfect answer. In most technical rounds they are judging how you reason: whether you clarify the problem, choose a sensible approach, test your own work and communicate along the way. A candidate who reaches a partial solution while thinking clearly out loud often scores better than one who silently writes a complete answer nobody can follow. Knowing this shifts your goal from "be flawless" to "show how I think", which is both more achievable and closer to what the job needs.

Build confidence that is earned

Reframing helps on the day. Lasting confidence comes from evidence that you can do the task under interview conditions.

Practise the format, not just the content

Solving problems alone at your desk is different from solving them while talking to a stranger. Practise out loud: explain your approach before coding, narrate your SQL as you write it, and summarise your answer at the end. The mock interview guide shows how to set up useful practice sessions.

Keep a record of what you can do

After each practice session, write down one thing you did well and one to improve. After a few weeks, the list of things you did well is concrete evidence against the feeling that you are not ready.

Prepare your stories

Behavioural questions are easier when you have five or six project stories ready in a clear structure. Behavioural interview questions for data roles shows how they are scored.

A routine for the day

The night before: stop studying in the early evening, prepare what you need (links, ID, water, a pen and paper), and sleep.

An hour before: solve one easy problem you know you can do, to warm up. Read your project stories once.

Ten minutes before: check your setup, then breathe slowly and tell yourself you are excited.

In the interview:

• Restate the problem in your own words and ask clarifying questions. It buys time and shows structured thinking.
• Say what you are thinking when stuck: "I'm considering two approaches; the first is simpler but slower." Silence is what makes interviewers worry, not uncertainty.
• Start simple. A working basic solution, then improve it.
• Recover openly if you make a mistake: "I see a bug in my join; let me fix it." Recovery is a skill interviewers want to see.

Afterwards: write down the questions and how you answered, while you remember. Then let it go until you hear back.

When nerves are more than nerves

If anxiety stops you from applying at all, or the feeling that you do not belong is constant, read imposter syndrome in tech. Persistent anxiety that affects daily life is worth discussing with a doctor or counsellor.

SQL and Python practice under interview-style conditions is part of the Data Analytics course.

Sources

• Get excited: reappraising pre-performance anxiety as excitement (Brooks, Journal of Experimental Psychology: General, 2014) — PubMed (US National Library of Medicine)
• Turning the knots in your stomach into bows: reappraising arousal improves performance on the GRE (Jamieson et al., Journal of Experimental Social Psychology, 2010) — PubMed (US National Library of Medicine)
• Engineers can't gauge their own interview performance (interviewing.io) — interviewing.io