LeetCode
HackerRank
Project Euler
Codewars
CodeForces
Exercism
interviewing.io
Coderbyte
CodeTrain
Codecademy
TripleTen
Udemy
Udemy for Business
Scrimba
W3Schools
Pluralsight
CodeTrain is a hands-on AI trainer for developers.
Instead of writing code for you, it turns any question, repo context, or onboarding task into a short lesson on your own codebase: two to six small steps, each one typed by you in an editor with an instant run/test loop. The tutor grades every step, asks Socratic questions when you miss, and shrinks the step when you're stuck.
Pro adds repo mode with a single reviewable patch-back of the code you wrote; Team adds ramp dashboards and onboarding journeys. Free tier runs in the browser, ten sessions a month, no card. Github link to the free skill is provided.
LeetCode CodeTrainCodeTrain's answer:
CodeTrain is an AI coding tutor that never writes the code for you, and that refusal is built into the architecture rather than a system prompt. It plans a short lesson from your own codebase (in repo mode), sets up 2 to 6 tiny steps, runs the code you type, and grades every step against explicit criteria. When you get stuck it shrinks the step or sharpens the hint. There is no code-generation path to talk it out of, which is the part every chat-based tutor gets wrong.
CodeTrain's answer:
Coding assistants like Copilot and Cursor are built to produce code. CodeTrain is built to produce engineers who actually understand the code. Learning platforms like Codecademy teach generic curriculum and measure completion, but they never touch the codebase you actually work in. Chat tutors hand you the answer if you ask persistently enough. CodeTrain grades what you typed, on your own repo, and the answer never comes for free. Use it alongside your assistant, not instead of it.
CodeTrain's answer:
Developers who use AI assistants daily and can feel their understanding of their own systems slipping. Junior engineers who ship AI-written diffs they couldn't rewrite. And engineering managers who want new hires ramped on the team's real codebase, with a dashboard showing who's progressing, who's over-relying on skips, and what each seat costs.
CodeTrain's answer:
I was building InferHaven, a privacy-first AI dev workspace company, and caught myself approving AI-written diffs I could not have rewritten from scratch. InferHaven exists so teams don't hand their code to vendors; CodeTrain extends the same instinct to the second thing quietly leaving the building, the skill in engineers' heads. So I built the opposite of an assistant: a tutor that plans, runs, and grades, but never types your solution. It launched publicly in Julyย 2026.
CodeTrain's answer:
FastAPI and PostgreSQL on the backend, primarily Claude models for tutoring, CodeMirror for the editor, and Pyodide so free-tier Python and JavaScript run entirely in the learner's browser. Shell and other runtimes execute in isolated server sandboxes. Clerk handles auth, Stripe handles billing, and bring-your-own-key support covers Anthropic, OpenRouter, Bedrock, Vertex, and Ollama.
CodeTrain's answer:
Too new to drop names honestly: CodeTrain launched publicly in Julyย 2026. Early users are individual developers on the free and Pro tiers, with the first team pilots in progress. If a public logo matters to you, check back in a quarter.
LeetCode is the best platform to help people practice solving coding problems and prepare for technical interviews. The main users are software engineers. LeetCode has over 1,900 questions covering many different programming concepts.
Based on our record, LeetCode seems to be more popular. It has been mentiond 543 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Category Tool URL How I used it General AI assistant ChatGPT Https://chatgpt.com Breaking down concepts, simulating interviewers, reviewing answers AI writing / reasoning Claude Https://claude.ai Refining behavioral stories and system design explanations Coding practice LeetCode Https://leetcode.com Core DSA practice and timed coding drills Coding explanations NeetCode Https://neetcode.io Pattern-based... - Source: dev.to / about 2 months ago
Plain BST. Fine when input is random or the problem doesn't require worst-case guarantees. Tree problems on LeetCode typically assume balanced input and don't ask you to maintain balance yourself. - Source: dev.to / about 2 months ago
Your preparation should not be random. Platforms like LeetCode, Codeforces, and GeeksforGeeks are toolsโbut what matters is how you use them. - Source: dev.to / 3 months ago
Bash /path/to/chrome-launcher.sh email001@gmail.com https://leetcode.com. - Source: dev.to / 3 months ago
AI-Powered Learning Tools: Consider using AI-driven platforms like Khan Academy or LeetCode that can personalize your learning experience based on your progress and skill level. - Source: dev.to / 10 months ago
HackerRank - HackerRank is a platform that allows companies to conduct interviews remotely to hire developers and for technical assessment purposes.
Codecademy - Learn the technical skills you need for the job you want. As leaders in online education and learning to code, weโve taught over 45 million people using a tested curriculum and an interactive learning environment.
Project Euler - Project Euler is a series of challenging mathematical/computer programming problems that will...
TripleTen - TripleTen: online part-time coding bootcamps.
Codewars - Achieve code mastery through challenge.
Udemy - Online Courses - Learn Anything, On Your Schedule