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AI can write the code.
It can't make you think.

Every prompt you outsource is a skill you don't build.Linfy is the training ground where you do the reasoning — and become the engineer AI can't replace.

promise.spec.ts
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describe('myPromiseAll', () => {
it('resolves values in input order', async () => {
const result = await myPromiseAll([
delay(30).then(() => 'a'),
Promise.resolve('b'),
]);
expect(result).toEqual(['a', 'b']);
});
});
PASS promise.spec.ts
Tests: 1 passed, 1 total
Time: 0.38s
How it works

You solve it. AI reviews it.

No autocomplete shortcuts. You reason through every problem, push real code, and get feedback that sharpens your judgment instead of replacing it.

Pick a real problem

Choose a track — rebuild a core library or ship a full product. No hand-holding, no shortcuts.

Reason it out & push

Work through the solution yourself in a real Git repo. Every push runs the full test suite.

Get feedback that teaches

AI reviews your work and explains the why behind every fix — so the lesson actually sticks.

Think before you type

Test-driven development forces you to define the problem before you solve it — the opposite of letting autocomplete guess. It's the discipline that builds real engineering judgment.

STEP 01

Define the Problem First

Write a test that describes the behavior you want before any code exists. This forces you to think, not autocomplete.

FAIL Expected: 5
STEP 02

Solve It Yourself

Write the minimum code needed to make the test pass — by reasoning through it, not guessing what a model would suggest.

PASS All tests passing
STEP 03

Refactor with Confidence

Clean up your code knowing your tests have your back. Improve the design without breaking what works.

CLEAN Code optimized

Built to make you think, not depend

Every feature is designed to build judgment you keep — not a dependency you rent from a model.

Real Terminal, Real Tools

Work in an actual dev environment with Git, npm, and your editor — no sandbox that thinks for you.

Git-Based Workflow

Push code to real repositories. Get feedback from automated CI pipelines, not a chatbot guessing your intent.

Production-Grade Code

Write code that meets industry standards with linting, testing, and code review you actually understand.

Feedback That Explains Why

See test results in real time and learn why your reasoning held up — or where it broke down.

Track Your Progress

Build a portfolio of problems you solved yourself. Show employers judgment, not just output.

You Write Every Line

No passive tutorials, no copy-paste from a model. Every project forces you to solve it yourself.

Become the engineer AI can't replace.

AI isn't going away. The developers who thrive are the ones who can still think without it. Start building that edge today.

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