Codility Lab

Skills assessment that produces evidence rather than a score.

Open research on what counts as proof that a person can do the job. Engineering is where we have gone deepest, across almost two decades. AI skills in the roles that now work with AI is newer work, and we publish it as the evidence develops.

Everything here is open. No forms, no gates.

Featured from the Lab

This month
Codex next to Claude Code in VS Code Preview
AI skills evidence in task reports Preview
The Task Randomizer, for every account Live
Latest release November 2026

See how well candidates use Claude Code and Codex · Nov 2026 update

Codex now runs next to Claude Code in Codility, and task reports show which AI skills a candidate used, quoting their own prompts. Plus the Task Randomizer for every account, two design tasks with no code and task collections.

Latest from the Lab

Article

The Binance heist started with a job interview. Your take-home runs the same risk in reverse

Building Engineering Teams
Article

How to assess AI skills in business roles with evidence your legal team can review: Codility AI for Business for assessment leaders

Assessment Research
Article

How to Hire AI-Native Engineers: What to Test, and What to Score

AI and Hiring
Article

What will hiring look like in 2027? 6 shifts the research points to

AI and Hiring
Article

How do you see how well a candidate works with Claude Code or Codex?

AI and Hiring
Article

What did Codility release in summer 2026?

AI and Hiring
Research

Codility on Reddit: what 429 threads say and get wrong

Assessment Research
Article

How do you assess AI skills when you hire?

AI and Hiring
Article

The case against AI interviews

AI and Hiring
Article

How do you run early careers hiring at scale without losing the signal?

Skills-Based Hiring
Article

Technical assessment ROI meta-analysis: 18 programs with measurable returns

Building Engineering Teams
Article

Why detecting AI use is the wrong question

AI and Hiring
Article

How do you prevent cheating in coding assessments?

AI and Hiring
Tools and Frameworks

What does the EU AI Act require for engineering hiring?

Compliance
Research

Inside the Engineering Skills Model: what it measures, how it works, and what changed in 2.1

Assessment Research
Article

Traditional validation was built for a slower world. Careers got shorter and hiring got faster

Assessment Research

Frequently asked questions

Proof that a person can do the job, produced by doing real work, with AI where the job uses it, and scored against a documented methodology. It is what a decision can be defended with when a candidate, a regulator or a client questions it.