Interview method · Part 1 — Communication fundamentals

The 10 Common Mistakes in IT Interviews

Identifying and fixing the 10 most common mistakes seen across hundreds of IT interviews — the ones that cost qualified consultants assignments and jobs.

Audience All IT profiles

Use Interview preparation · Self-assessment · Coaching

Core principle

A communication problem, not a skills problem

Most interview mistakes don't come from a lack of skill. They come from a lack of preparation for the exercise of communication itself.

Entry-level version

Knowing these mistakes before your next interview gives you an immediate edge.

Senior consultant version

These mistakes are especially costly for senior profiles — an experienced candidate who makes them sends a signal of low professional maturity.

Step-by-step breakdown

3 mistakes worth understanding in detail

Mistake #1 — The question behind the question

Every question has a surface level and a real level. Strategy: answer both levels at once.

Mistake #2 — The collective "we"

"We migrated the infrastructure to AWS in 6 months."

"I designed the target architecture and coordinated 3 teams to migrate the AWS infrastructure in 6 months. My specific role was the migration strategy and technical governance."

The recruiter is assessing your contribution. "We" dilutes your value.

Mistake #5 — Criticising your previous employer

Even when the context was genuinely difficult, direct criticism sends an immediate risk signal: "This person will talk about us the same way." Technique: describe the facts, not the judgements.

"My manager was incompetent and understood nothing about architecture."

"The context was challenging: little visibility into the technical roadmap, architecture decisions made without consulting the teams. I decided to leave when I realised I no longer had the conditions to deliver value."

Example

Preparing your close

The "Do you have any questions?" at the end of the interview is an opportunity, not a formality.

Questions to avoid

✕"What's the salary?" (too early)
✕"How many days of leave?" (the wrong priority)
✕"No questions" (zero interest)

Questions that impress

✓"What are the 2 or 3 main challenges you expect this person to tackle in the first 6 months?"
✓"How would you describe the team's technical culture — more specialised or more generalist?"
✓"What makes a consultant genuinely successful in this context?"

Senior profiles

Mistakes specific to senior profiles

Mistakes #7 and #8 are especially costly for profiles with 8+ years of experience:

✕Showing up with no research on the company is disqualifying for a senior role. The client/recruiter expects you to have done your due diligence.
✕Always being right: senior profiles who acknowledge no limit, no self-questioning, nothing learned recently create immediate distrust. Seniority also means knowing what you don't know.

Before the interview

Full pre-interview checklist

Preparatory research

✓I've read the company's website + its recent news (last 6 months)
✓I know the sector's challenges and the relevant regulations
✓I've found my interviewer's LinkedIn profile

Content

✓I've prepared 6-8 STAR examples covering: success, failure, conflict, innovation, leadership, pressure
✓Every example is dated and quantified
✓I consistently use "I", not "we"

Format

✓My answers last between 2 and 3 minutes
✓I've prepared 3 relevant questions for the end
✓I know how to adapt my technical level to my audience

Key takeaways

Preparation changes everything

The best technical skills don't make up for unstructured communication. All 10 of these mistakes are fixable with preparation — not innate talent. 45 minutes of preparation before an interview can completely change the outcome.

← Back to this part's contents

Want one-to-one support to prepare for your interviews?

An outside perspective to build your bank of examples and rehearse under real conditions.