Practice for working developers
Stay sharp after years in the same stack.
Devhone pinpoints the fundamentals you've let go rusty — data structures, algorithms, concurrency, SQL — and serves short, focused reps aimed exactly where you're weak.
Free during the beta. Sign in with GitHub — no credit card.
You could ship this feature in your sleep.But could you write a clean graph traversal from scratch?
You've spent years getting deep in one codebase. You know its quirks cold, you make the right calls under pressure, and the team trusts your judgment. That's real expertise — and none of it is going away.
But the muscles you don't use go quiet. The DP solution that used to be obvious now takes three false starts. You reach for the framework helper because you can't quite remember how the lock should be scoped. The fundamentals are still in there — they've just gone rusty from disuse.
Devhone is the whetstone. A few focused reps, aimed at the skills you've actually let slip, so your edge comes back and stays.
How it works
How Devhone keeps you sharp
No 300-problem grind. Just the right reps, in the right places, at the right time.
We map where you've gone rusty
A short calibration across core topics shows where you're fluent and where you're reaching for help. Devhone tracks topic, recency, and how much of a hint you needed — so the map reflects real fluency, not a quiz score. Newer to a topic rather than rusty on it? Same map — it simply shows more ground to build.
You do short, focused reps
Get curated problems aimed squarely at your weak areas — 15 minutes, not a marathon. Smart selection pulls more from the topics where you struggled and eases off the ones you've clearly got.
Your edge stays sharp over time
Skills fade without use, so Devhone resurfaces topics on a spaced cadence right before they'd slip again. Keep your fundamentals loaded with a few reps a week instead of a weekend of cramming.
Topics
Cover the fundamentals that fade first
Curated problems across the core skills that quietly erode when your day job stops exercising them — or that you never got the reps to build in the first place.
Data structures
Trees, graphs, heaps, hash maps — building and traversing them without reaching for a library.
Algorithms
Sorting, searching, recursion, dynamic programming, and knowing which one the problem is actually asking for.
Concurrency
Threads, locks, races, and async models — reasoning about what runs when, and what can go wrong.
SQL & query thinking
Joins, window functions, and set-based logic for when the ORM stops being enough.
System fundamentals
Memory, caching, I/O, and the cost model underneath the abstractions you lean on daily.
Complexity & performance
Reading Big-O off a solution and spotting the line that turns linear into quadratic.
Strings & parsing
Tokenizing, matching, and the kind of careful index work that's easy to fumble out of practice.
Math & logic
Bit manipulation, modular arithmetic, and the discrete-math reflexes the right problem still needs.
FAQ
Questions, answered straight
Devhone is built first for experienced developers reloading fundamentals they've let go rusty — that's the main focus, and the content assumes you can already code. That said, if you're earlier in your career and want to build those fundamentals for real instead of just passing a class, the same adaptive practice works for you too. What it isn't is a 'learn to program from zero' course.
Not the goal — but it helps. Devhone is built for staying sharp on the job, not gaming a 45-minute screen. That said, the same fundamentals show up in interviews, so if you've got one coming, you'll walk in warmer.
LeetCode hands you a giant, undifferentiated pile and leaves you to grind. Devhone is curated and adaptive: it detects where you've actually gone rusty and serves more practice there, then spaces it out so it sticks. Less volume, better aim.
Devhone is about fundamentals, not syntax trivia, so you'll be able to work in the mainstream languages you already use day to day. More detail on the exact lineup as we get closer to launch.
It's designed around short, frequent reps — think fifteen focused minutes, a few times a week. The spaced cadence does the heavy lifting so you don't have to block out a weekend.