Who This Is For¶
PatternDojo is built for two kinds of people, on the same path.
If you can write code — loops, functions, arrays, a hash map — but freeze when handed an unfamiliar problem, you're the first kind. You never built problem-solving intuition, because nothing ever made you. Maybe you learned with AI at your side, and when the AI goes away, so does your ability. You don't need a syntax tutorial. You need structured practice at the right difficulty, with clear signals for when to reach for each tool.
If you used to solve problems like these fluently and now you can't, you're the second kind. You're an experienced developer — you can architect a system, debug a production issue, reason about complex code — but your problem-solving skills have quietly atrophied from leaning on AI assistants. The algorithms you once knew feel out of reach. That's not a skill gap; it's a muscle that stopped getting used. It comes back.
Both of you start from the same place: you can write syntax. Neither of you needs a tutorial. What you need is the path — which problems, in what order, with honest teaching about when each approach works and when it doesn't.
What this site is¶
It's a guided path through coding practice problems, organised by the problem-solving pattern each one teaches. The problems themselves live on existing judges (LeetCode and a few others). This site doesn't host them and doesn't grade them. What it gives you is everything around the problem: the pattern teaching, the order that builds each concept on the last, the triggers that tell you when to reach for it, and — critically — the anti-triggers that tell you when not to.
What it is NOT¶
- Not a syntax tutorial. You should already be able to write a loop, use a hash map, and understand function calls in your language of choice. If you need that, the language docs and W3Schools are free and excellent.
- Not an interview-prep cram sheet. There are great free ones (NeetCode, Blind 75, Grind 75) that will serve you better if you just want a list of problems. This site exists because a list of problems is not a pedagogy.
- Not a place to read solutions. Nothing here will solve a problem for you. The teaching tells you what the pattern is and when to use it — you still have to write the code yourself. That's the whole point.
Where to start¶
If you're new to structured practice or haven't solved a problem on a coding judge before, start at Stage 0 (Warm-Up) and walk the sequence straight through. It's short by design — just enough to prove the machinery works — and then Stage 1 begins.
If you're an experienced developer returning after a gap, skim Stage 0 (or skip it entirely) and begin at Stage 1. Every pattern page has a "test out" note on its hardest problem. Try it. If it's easy, move on to the next pattern. If it tangles you up, work the set from the top. You never have to self-rate or guess — the challenge problem tells you where you stand.
The honest note about AI¶
This is worth naming directly. Relying on AI to generate code means the problem-solving muscle stops getting used, and it weakens. For beginners who never built it, that muscle never develops. For seniors who once had it and stopped practising, it atrophies — and the feeling of "I used to be able to do this" is genuinely unsettling when it's your own brain you're supposed to trust.
The solution isn't to stop using AI. That ship has sailed, and pretending otherwise would be both dishonest and unhelpful. The solution is to use AI deliberately — as a tutor, a reviewer, an explainer — while keeping the actual problem-solving reps for yourself. That's the skill this roadmap rebuilds. The patterns, the triggers, the judgment about which tool fits — those don't come from a prompt. They come from doing the work.
You're here. That means you already know this. The roadmap just gives you the structure to follow through.