Realistic challenges, not puzzles

Every scenario is based on real production incidents. Candidates debug actual problems with real tools—the same way they would on the job.

Scenario library

Ready to use today. Based on real production incidents.

Fraud Detection Latency

An ML feature service returns in ~100ms for most clients but 10-30s for one. Candidates must use observability to identify why, then fix the root cause.

FastAPI PostgreSQL asyncpg Grafana

Checkout Double-Charge

Intermittent double-charges in a checkout flow. Candidates must identify the race condition and implement a fix that handles concurrent requests safely.

Go PostgreSQL Redis

Memory Leak Investigation

A Node.js service's memory usage grows until it OOMs. Candidates use profiling tools to identify the leak and fix it without breaking functionality.

Node.js Express Prometheus

Model Accuracy Regression

A deployed PyTorch model is returning predictions but accuracy has dropped significantly since last week. Candidates investigate the pipeline to find what changed.

Python PyTorch FastAPI

Sales Report Discrepancy

Finance flagged that the monthly sales report is wrong—numbers don't match the source data. The query has cross joins and window functions. Something's silently inflating totals.

PostgreSQL SQL

Dashboard Data Mismatch

An executive dashboard is showing different numbers than the underlying data. Candidates debug the notebook, fix the aggregations, and correct the visualisations.

Python Pandas Jupyter Plotly

Or bring your own

Have an incident that would make a great hiring filter? We'll work with your team to turn it into a reproducible scenario with isolated infrastructure.

What we build for you

Your stack, replicated and isolated
Realistic data and failure conditions
Full observability tooling
Automated pass/fail criteria
LLM baseline for comparison
500 candidate minimum for custom scenario setup

Not sure which scenario fits?

Book a demo and we'll help you pick—or design something custom for your team.

See pricing