GodSang

We'll help you figure out what to do with time that just opened up.

The main thing here
🛠

Implementation Gym

Read a real spec, build it yourself, get graded by hidden tests

Recommenders, search rankers and CTR pipelines through gradient-descent regression, k-means and backprop — the implementations you actually meet at work, solved right in your browser. This trains turning prose specs into exact code, not memorizing algorithms.

Start solving →

BRAIN WARM-UP

🔢

Math

Wake up your brain
with basic arithmetic

🔤

Vocabulary

Boost your focus
with vocabulary tests

📖

Reading

Build comprehension
with passages and inference

📊

Stats/ML

Sharpen your math skills
with quant/DS problems

📈 Today's Top Momentum Stocks

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What you can do here

GodSang is a small set of tools for getting started on work you have already decided to do. Everything below is open without an account.

Implementation Gym — build from a spec

Read a long requirements document and turn it into working Python, level by level, with hidden tests grading each submission. This is the main thing on the site: 34 problems covering data plumbing (sessionizing event logs, reconciling transactions, rate limiters, LRU caches) and machine learning written from scratch (gradient-descent regression, k-means, naive Bayes, MLP backpropagation, a search ranker, a CTR pipeline).

Nothing is multiple choice and nothing is an algorithm quiz. The skill being trained is reading prose requirements carefully enough to implement them exactly — which is where most real work actually stalls.

Code runs in your browser through WebAssembly Python, so your solution never leaves the page and no account is needed to solve a problem.

Brain warm-up — two or three minutes before you start

Four short drills for when the task is clear but you cannot get moving: mental arithmetic, English vocabulary in context (4,700+ questions), reading comprehension (1,100+ questions), and statistics and machine learning (460+ questions across probability, statistics, linear algebra, ML and deep learning).

Each one adapts: questions carry a difficulty rating, you carry one too, and an Elo-style update moves yours after every answer. The score exists only to pick your next question — there are no leaderboards.

Market tools

A momentum screener and related summaries computed from public market data on a fixed schedule. The plans page lists what each tier covers.

These numbers are produced by an algorithm and are not investment advice. Past figures do not predict future returns, and every investment decision remains your own.

About this site

Built and run by one person. Problems, explanations and interface copy are all written here rather than collected from elsewhere. Changes are logged on the updates page.

More on how the content is made, how ads are placed, and how to get in touch is on the about page (Korean).