What is a competency-based interview?
A competency-based interview (also called a behavioural interview) tests specific skills and behaviours using structured questions about your past experience. Instead of asking "are you a good leader?", the interviewer asks "tell me about a time you led a team through a challenge."
The logic: past behaviour in real situations is a stronger predictor of future performance than abstract self-assessments.
They're used by:
- Most FTSE 100 and Fortune 500 companies
- UK Civil Service (the entire interview framework is competency-based)
- Professional services firms (Big Four, McKinsey, Deloitte, etc.)
- Virtually all graduate schemes
- Most mid-to-senior management roles
How competency interviews are scored
This is what most candidates don't know: interviewers typically work from a structured scorecard. Each competency has a set of positive indicators (behaviours they want to see) and negative indicators (red flags).
Your answer is scored — usually 1–5 or 1–7 — based on how clearly you demonstrate the indicators.
Typical positive indicators for "Leadership"
- Clearly set direction and goal
- Took personal responsibility for outcomes
- Adapted approach based on team needs
- Delivered measurable result
If your answer doesn't hit those points explicitly, you score lower — regardless of how genuinely good the underlying experience was.
Implication: Knowing the competencies in advance lets you pre-load your answers with the right evidence.
The most common competency frameworks
UK Civil Service Success Profiles
The Civil Service scores candidates against five elements:
- Behaviours (e.g. Communicating and Influencing, Making Effective Decisions)
- Strengths (genuine enthusiasm and natural talent)
- Experience (relevant track record)
- Technical (role-specific skills)
- Ability (situational judgement)
Most roles at Grade 7 and below focus heavily on Behaviours. Senior roles add Strengths and Experience.
Competency frameworks at professional services firms
Firms like Deloitte, EY, PwC, and KPMG typically score against:
- Problem-solving / analytical thinking
- Communication and influencing
- Teamwork and collaboration
- Leadership and taking initiative
- Commercial awareness
- Resilience and adaptability
Tech companies (Google, Amazon, Meta)
Amazon is famous for its 16 Leadership Principles. Every interview question maps to one. Common ones tested:
- Customer Obsession
- Bias for Action
- Dive Deep
- Ownership
- Deliver Results
Know the specific framework of your target company. It's almost always published.
The STAR method: your answer framework
The STAR method (Situation, Task, Action, Result) is the standard structure for competency answers. Read our full STAR guide here.
Quick version:
- Situation: Brief context (15% of answer)
- Task: Your specific role/responsibility (10%)
- Action: What you did, step by step (60%)
- Result: Measurable outcome (15%)
The most common failure: spending too long on Situation and not enough on Action.
How to prepare: a practical process
Step 1: Map your competencies
Research the competency framework your target employer uses. Most publish it in their careers section or graduate recruitment materials. If they don't, search for "[Company name] interview competencies" — candidate forums often list them.
Make a list of the top 6–8 competencies you'll be tested on.
Step 2: Build your story bank
For each competency, find at least one strong example from your experience. Aim for 6–8 stories total — some will cover multiple competencies.
Good sources of material:
- University projects and dissertations
- Part-time or summer work
- Sports, societies, and leadership roles
- Volunteer or charity work
- Any situation where you faced a genuine challenge
Step 3: Write out your STAR answers
Write them down in full, then cut them back. Aim for answers that run 1.5–2.5 minutes when spoken aloud.
Step 4: Practise out loud
This is the step most candidates skip, and it's the one that matters most. There is a significant gap between an answer that reads well and one that sounds fluent and confident when spoken.
Practice out loud at least 3–5 times per story until it flows naturally. Recording yourself and watching it back is uncomfortable but highly effective.
Step 5: Get feedback on the right things
Competency interviews assess:
- Answer quality: Does your answer hit the competency indicators?
- Structure: Is the STAR framework clearly followed?
- Delivery: Voice pace, filler words, confidence
- Conciseness: Does the answer stay focused?
AI Career Mentor scores all four dimensions and flags specific weaknesses in each answer. Try it free →
On the day: interview tactics
Listen for the exact competency being tested
"Tell me about a time you had to manage a competing priority" → Prioritisation / Time management "Describe a situation where you had to adapt your communication style" → Communication / Influencing
Pick your strongest relevant story. Don't waste a great leadership story on a communication question.
Ask for a moment if you need it
It's completely acceptable to say "Let me just think about the best example for that." A 5-second pause to think is better than launching into a weak example.
Quantify where you can
Numbers make answers more credible and memorable. "Improved response time" is weaker than "cut average response time from 48 hours to 6 hours." Keep a note of your measurable achievements before the interview.
Don't catastrophise negatives
Questions like "tell me about a failure" are not traps — they're designed to test self-awareness and resilience. Pick a real failure, explain what you did wrong, and spend equal time on what you learned and what you changed afterwards.
After the interview
If you don't advance, ask for feedback. Most employers will give some, and even vague feedback ("your examples could be more specific") tells you what to work on.
If you do advance — practise again. Repeat rounds at most employers test the same competencies more deeply.
The difference between candidates who pass competency interviews and those who don't rarely comes down to the quality of their actual experience. It comes down to preparation. Start practising with AI feedback →