Buglyst
Explore Practice
Quick Practice Arena

Train debugging instincts in short rounds.

No sandbox. No setup. Just fast pattern recognition, value tracing, diff judgment, and repro reasoning.

grid_view5 categoriesstyle25 curated promptstimer~5 prompts per roundsaveProgress saved on this device
Curated micro-practice. Progress is saved locally on this device. Prompts are fictional, pattern-based snippets — not real issues or company problems.
Your local progressSaved locally on this device

No rounds played yet on this device. Pick a category or start the daily run — your stats and badges will appear here, saved locally.

calendar_today

Daily Mixed Run

One prompt from each category, the same deck for everyone today. A fast five-round warm-up.

Start daily run

Pick a category

ads_click
5 prompts

Bug Spotter

Click the exact buggy line in a short snippet.

Play round →
difference
5 prompts

Diff Detective

Spot the risky changed line in a small diff.

Play round →
route
5 prompts

Trace the Value

Predict the output or final value before it runs.

Play round →
construction
5 prompts

Patch Picker

Choose the safest minimal patch for the bug.

Play round →
account_tree
5 prompts

Repro Chain

Order the steps into a clean reproduction.

Play round →
scoreboard

How a round is scored

Each prompt is graded objectively out of 100 — the exact buggy line, risky diff line, correct value, or safest patch scores full marks, and repro ordering earns partial credit for near-misses. After every answer you get the explanation and the pattern to remember. Progress is local to this device only.