Learn it. Get grilled on it. Keep it.

Guided lessons you can interrupt and argue with, out loud. Mock interviews that score you. A pair programmer that watches your screen. Everything you miss comes back on a schedule until it sticks.

Learn — A guided lesson per topic, read aloud if you want. Stop it mid-sentence and ask.
Practise — Quizzes and flashcards. Anything you miss comes back on a spaced schedule.
Interview — Talk to an interviewer that follows up, scores you, and flags the gaps.
Pair — Share your screen and write real Kotlin with a coach that can see it.

No sign-up to learn. Voice sessions need an account.

Lessons, quizzes and flashcards are free. Voice sessions run on credits (you start with 50), or go Unlimited for $20 a month.

All 81 topics