Codility AI-Native Tasks: assess engineers who build with AI

AI can write the code.
We assess the engineers who can build with it_

AI-Native Tasks are built from the start around AI-assisted engineering in a real VS Code environment, where using the AI Assistant is core to the task and treated as an engineering skill that separates strong engineers now.

10 tasks live now across Interview, Screen, and Skills Intelligence

Two kinds of task

Hiring teams now need to test two distinct things: can a candidate build AI products, and can a candidate work effectively alongside an AI Assistant, including knowing when to doubt it. The 10 VS Code tasks live today cover both: three build AI, seven work with AI.

Build AI

The candidate builds the AI system itself, and we score how they design and harden it. A grounded retrieval assistant, or a statistically sound anomaly detector.

Work with AI

The candidate works alongside an assistant to debug, investigate, or create. We score how well they direct it and whether they catch it when it is wrong.

Some Work-with-AI tasks are built so that blindly trusting the assistant loses points, because that is the real job.

Build AI

3 tasks live

The AI or ML system is the deliverable. The candidate is judged on standing up a working product.

Easy40 minConverse

Legal Document Q&A Assistant

Implement a retrieval pipeline that answers natural-language questions about a legal document archive. It returns a generated answer alongside the source chunks it retrieved, so grounding can be checked.

LangChainFAISSRAGPython
Back-end Developer
Medium50 minDetect

DataSentinel

Build an anomaly-detection pipeline that ingests daily KPI readings, persists history to a database, detects statistical anomalies, and emits a structured report. Solvable in the candidate’s language of choice.

Any languagePostgreSQLz-scoreJSON
Back-end Developer, Data Engineer
Hard60 minPredict

AI Model Churn

Build a churn prediction model for a language learning platform, covering feature engineering, model selection, and evaluation of how well the model actually predicts.

PythonFeature engineeringModel evaluationML
Data Scientist

Work with AI

7 tasks live

A realistic engineering job alongside an assistant. The signal is how well the candidate directs it, and whether they catch it when it is wrong.

Medium50 minDebug

Order Router Microservice

Inherit a failing Python microservice, diagnose three latent production bugs, and get the test suite green. Maintenance work on code the candidate did not write.

PythonRoot-cause debuggingTest suiteMicroservices
Back-end Developer
Medium60 minDebug

Meeting Planner

Fix subtle bugs in an existing meeting planner, then build a new feature that suggests group time slots.

Root-cause debuggingFeature build
Medium80 minInvestigate

Log Analyzer

Build a tool that pulls incidents and patterns out of noisy, semi-structured logs and produces structured diagnostics.

PythonLog parsingPattern extraction
Medium80 minInvestigate

Chat Conversation Analyzer

Build a command-line tool that explores chat logs and extracts intent, topics, and participants from messy dialogue.

CLIText analysis
Medium50 minOptimize

Gallery Wall Curator

Solve an optimization problem, choosing items to maximize total value, designing and iterating heuristics with the assistant toward value thresholds.

OptimizationHeuristicsAlgorithms
Back-end Developer, Data Scientist
Medium50 minCreate

React Carousel Music Player

Build a React carousel music player with audio playback, track metadata, cover art, play and pause, next track, and progress scrubbing.

ReactAudio playbackUI
Front-end Developer
Hard60 minCreate

Task Scheduler

Implement a scheduler API with dependency management, cycle detection, topological ordering, and critical-path scheduling.

FastAPIPythonGraph algorithms
Back-end Developer

Companion tasks, AI optional

The library also carries project-style VS Code tasks where the AI Assistant is available but not required. Realistic, multi-file engineering work that stands on its own with or without an assistant enabled.

Scored against the Engineering Skills Model

Every task is tagged against the Codility Engineering Skills Model at the test-case level, so each task reports against the specific skills its checks exercise, for example prompt engineering and AI integration for the retrieval assistant, or AI output validation and critical thinking for the debug and investigate tasks. Recruiters get the same skills-based reporting as the rest of the library, mapped onto role profiles. Validated by engineering leaders.

The set runs 40 to 80 minutes across easy, medium, and hard, covering back-end, front-end, data engineering, and data science profiles, so the same library serves early screening and senior interviews.

10 tasks live, 3 build AI and 7 work with AIReal VS Code environmentTest-case-level skill taggingMaps to role profilesAI Assistant core to every task