For teams shipping AI-written code

AI writes it in minutes. Understanding it still takes weeks.

Crux writes short courses from the code actually in your repository, then checks — by asking — that the people shipping it can explain it.

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Read-only GitHub access. No card. Delete your repository data whenever you want.

kiasm/crux-webmainconnected

repository

kiasm/crux-webmain▾selected

TypeScript 71%CSS 18%JSON 7%Markdown 4%

what we ask for

Read: code and metadata, on the branch you name
Never: write access, pull requests, or pushes

then it reads

Repository tree read412 files
Import graph resolved1,140 edges
Modules carrying weight11 found

kiasm/crux-webmain6 courses

your courses

Structure

How a request reaches a page

app/(site) · routing, layouts, prerender

architectureapi

Code

Sessions and the auth guard

modules/auth · 3 levels

auth

Code

The datastore port and its two adapters

shared/server/datastore · 4 levels

datainfra

Concepts

Reading the repository…

Concepts

Reading the repository…

testing

Structure

Talking to GitHub without write access

modules/github · installs, scopes, webhooks

integrationsauth

kiasm/crux-webmainrecall check · 1 of 4

order the sequence

Put the request path in the order it actually runs.

1The page renders to HTML at build time
2Next matches the URL to app/(site)/page.tsx
3The browser hydrates the client components
4The (site) layout wraps it in header and footers

No multiple choice. Put them in order.

A real question type, simplified for this page. The product’s version drags, grades against the commit you connected, and does not tell you which rows were wrong.

kiasm/crux-webmainlast 26 weeks

comprehension by domain

FebMarAprMayJunJulArchitectureAuth & SecurityAPIDataInfra & DevOpsUI & FrontendTestingIntegrationsConcepts

lessmore

who knows what

Dimos9 modules verified
Francesco6 modules verified
Marco4 modules verified

Illustration. Real accounts start empty and fill in as people pass recall checks.

Demo data on one example repository — this site’s own. Every control here is a component the app ships; the panels that are drawn rather than live say so.

01 · the gap

Teams are merging code that nobody on the team can explain.

We asked 92 developers one blunt question: have you shipped code you did not fully understand? Fifty-six said yes. Not one said no.

Review catches defects. It does not catch the fact that the reviewer was guessing.

61%: have shipped code they did not fully understand
67.4%: reach for AI first in an unfamiliar codebase, ahead of docs and reading the code
5.4%: always understand a system before they change it
32.6%: say AI has made them understand code less deeply

n = 92 developers · Crux survey · fielded 7–20 Jul 2026

02 · what it does

It teaches your repository, not programming.

Crux resolves the import graph, finds the modules that carry weight, and writes a course per subsystem: the request path in your service, your auth model, the retry logic somebody wrote at two in the morning. Or type what a new joiner needs by Friday and it writes that instead.

kiasm/crux-webmaincourse 3 of 11

← back to courses

How this marketing site is assembled

architectureconceptsapiSkip to quiz →Page 1 of 7

What you’ll learn

A conceptual map of how the site is put together, so you can reason about changes without reading every component first. Where static pages, client-side navigation, prerendering and serverless data calls sit in one architecture.

after this course you’ll be able tocited from app/(site)/layout.tsx:14

·explain the main layers that make up the site experience
·describe how a visitor moves from first load to in-app navigation
·identify where SEO consistency comes from across pages
·explain how external data is fetched without exposing secrets

03 · verification

A course nobody passed proves nothing.

So the last step asks you to prove it. Each module ends with recall against the real code, and passing marks that person verified on that subsystem, at that commit. When the person who understood the payment flow leaves, you can see the hole before it costs you a weekend.

Order the calls
Name what breaks
Point at the line that swallows the error

verified · auth & sessions · 4 of 5 modules passed

Verified is per person, per subsystem, at a commit. It expires when the code underneath it moves.

Your mastery

Comprehension by domain over the last year

Depth: Structure ▾

AugSepOctNovDecJanFebMarAprMayJunJulArchitectureAuth & SecurityAPIDataInfra & DevOpsUI & FrontendTestingIntegrationsConcepts

lessmore

Illustration. Real accounts start empty and fill in as people pass recall checks.

04 · where it fits

Three moments teams use it.

01
Onboarding, without the four-month tail
The four subsystems a new hire will actually touch, in the order they will touch them, from this week's code.
architectureapi
day 1–5
02
Before you own a subsystem
Taking over billing or the queue is a short course and a recall check, not three weeks of learning by breaking it.
datainfra
~20 min
03
After the agents have been busy
When a model wrote most of a subsystem, Crux turns that diff into something a human can hold before it becomes on-call's problem.
authtesting
per PR

who is behind us

Three of us, out of DTU Skylab in Copenhagen, with a coach there and an outside mentor keeping us honest. More about us.

DTU SkylabHome base and startup programme at DTU.
Our Skylab coachMonthly sessions on the business side of this.
External mentorOutside the university.