The guided debugging platform for
real codebases.
Practice fixing real bugs in safe, ready-made labs. Read the failing test, find the cause, and ship the smallest fix — before real work throws one at you.
No setup. No account needed. Fix your first bug in minutes.
Cache key missing tenant id
Multi-tenant cache key uses just user_id, causing cross-tenant leaks.
Open incident →Where do you want to begin?
Wherever you are — first bug or hundredth — there's a real, ready path that meets you there.
Core Labs
Reproduce a failure, patch the code, and validate the fix in an isolated codebase.
20 playable · 35 plannedExplore core labsFailure Entry Modes
Review a risky diff, map a codebase, diagnose red CI, or investigate an incident.
Review · Navigate · CI · IncidentsChoose a modeQuick Practice
Sharpen pattern recognition with short, curated debugging prompts.
5 categories · 25 promptsStart a quick roundDebug whole codebases, not snippets
Open a real repo with a real failure and find your way around it — the same disorientation as day one on a new team, in a safe place to practice.
Prove your fix actually holds
Passing the test you can see isn't enough. We run extra checks afterward to confirm you fixed the real cause and didn't break anything else.
Walk away with proof
Every fix you land becomes a short, shareable summary of what you solved — proof you can debug real systems, with nothing spoiled.
One platform, six ways to practice engineering judgment.
Choose the evidence you want to start from. Every mode trains a different part of the same debugging loop.
Fix real bugs
Core debugging labs
Review risky changes
PR-style review cases
Navigate unfamiliar systems
Curated codebase maps
Diagnose CI failures
Fictional red pipelines
Investigate incidents
Production-style scenarios
Train quick instincts
25 curated micro-prompts
Get your reps before your first real PR.
Opening a popular open-source repo for the first time is intimidating. OSS Labs replay real public bug-fix history as guided challenges, so you practice on actual project code first — no pressure, and no pretending you made the upstream PR.
Safe copies of real repos
Real bugs, recreated safely
A test you can see
A summary you can explain
Proof you can share
Practice only, not a real PR. Labs are based on public bug-fix history, recreated safely.
How Buglyst compares.
We're fans of the tools below — they each do their job well. Buglyst just sits in a different spot: the gap between solving puzzles and actually debugging unfamiliar code, with guided onboarding and zero setup.
Swipe to compare →
| Aspect | LeetCode / HackerRank | Recticode | Exercism | Best for real debuggingBuglyst |
|---|---|---|---|---|
| Core focus | Algorithmic puzzles | Real bugs via CLI | Mentored exercises | Guided debugging of real codebases |
| Experience | Browser snippet editor | Local CLI (pip install) | Browser + mentorship | Rich VS Code-style browser workspace |
| Onboarding | None | None (experienced devs) | Some guidance | Structured guidance across practice modes |
| Languages | Multiple (algo-focused) | Python-heavy | Multiple | JS/TS + Python + Java + C++ OSS labs |
| Content type | Synthetic puzzles | Community real bugs | Curated exercises | Curated + real OSS bug-fix history + company-style tracks |
| Guidance level | Minimal | “No hand-holding” | Mentorship | Step-by-step coach cards, spotlights, diffs |
| Career artifacts | Leaderboards, streaks | Event badges | Certificates | Verification URLs, PR-style reports, OSS readiness profile, shareable badges |
| Target user | Interview prep | Terminal-comfortable devs | Learners seeking feedback | Students, juniors, bootcamps, interview/career prep |
| Setup required | None | pip install + local run | None | Zero setup — open browser and start |
| Progression | Streaks, contests | Competitions | Mentorship tracks | XP, levels, badges, streaks, recommendations, skill coverage |
Comparison reflects Buglyst's positioning as of the current beta. Other products are independent and unaffiliated; capabilities described are based on their public materials and may change.
Debugging playbooks
Concise learn pages for env vars, cache stampedes, CORS origin bugs, retries, timezones, pagination, stale locks, and tenant cache bugs — each linking back to ready practice incidents.
Open Learn →Progress without inflated claims
Profile brings core lab records and local-only mode progress into one honest view. It shows what you practiced without inventing rankings, certifications, or hiring claims.
View Profile →The fastest way to understand it is to fix one bug.
No setup, no account. Open an isolated repo, reproduce the failure, ship the fix, and feel the loop that real engineering runs on.