LESS MEMORIZING. MORE UNDERSTANDING.
Stop reading AI code.
Start leading it.
Knowing the answer is one thing. Knowing why is another. Practice real-world scenarios and get feedback that helps you think one step further.
Try guest practice. No account needed.
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The endpoint returns an order by ID.
The tests pass. What could go wrong?
14async function getOrder(id, user) {15- return db.orders.find(id, user.id);15+ const order = await db.orders.find(id);16+ if (!order) throw new NotFound();17+ return order;18}Who should be allowed to see this order?
One sharper you.
Real-world scenarios
Your own reasoning
Specific feedback
FIND YOUR PRACTICE
Different challenges.
Same muscle: judgment.
From your next pull request to your next system design. Choose where you want to get better.
Code review
Find the risk hiding in a seemingly harmless diff.
Read. Question. Review.System design
Make the tradeoffs. Then make the case for them.
Design for the real world.Debugging
Follow the evidence from symptom to root cause.
Less guessing. More reasoning.Data analysis
Turn queries, pipelines, and data into sound decisions.
Go beyond the numbers.Practical coding
Build a working solution, not just a clever one.
Implementation meets judgment.A SIMPLE PRACTICE LOOP
Think it through.
Then go a little deeper.
Pick your challenge.
Choose a practice area and a scenario. Start with the skill you want to sharpen, not a syllabus to finish.
Show your thinking.
Review a diff, explain a design, write code, or work through a question. Make your reasoning visible.
Find your next step.
Get feedback on your response. See what held up, what needs work, and where to focus next.
Not just
“looks good.”
MAKE EVERY ATTEMPT COUNT
The useful part
is what comes next.
A score can tell you where you landed. Specific feedback helps you decide where to go.
- See the gaps in your reasoning. Scenario-level criteria make the feedback easier to act on.
- Build on what you got right. Recognize your strengths, not just your mistakes.
- Keep your practice in perspective. Sign in to revisit your history and explore your dashboard.
BEFORE YOU JUMP IN
Good questions.
A few things worth knowing before your first scenario.
Can I try it without an account?
Yes. Guest practice gives you access to a selection of scenarios, subject to a daily session limit. Create an account to access the broader question library and keep your practice history in one place.
Is this for interviews or everyday work?
Both. LGTM focuses on explaining decisions, identifying risks, and reasoning through tradeoffs. Use it to prepare for technical interviews or to practice the kinds of decisions you encounter on the job.
How does the feedback work?
Written responses are evaluated by AI against scenario-specific criteria, with feedback on your reasoning and coverage. Multiple-choice questions use answer-key scoring. AI feedback can be imperfect, so use it as a learning aid, not a definitive assessment of your ability.
Do I need to be a senior engineer?
No. Pick a topic and difficulty that fit where you are now. The goal is to improve how you approach a problem, not to prove that you already know everything.
LESS SCROLLING. MORE SOLVING.
Your next good decision
starts with practice.
Pick one scenario. See where your thinking takes you.