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The rooms

Eight rooms, in the order the mistakes happen

From the prompt you send to the error nobody sees. Each room is a short reading with its sources, three points for your Review Card and two benches to practise on.

Hall Pass $1.95/month or $19.50/year · one room $1.00 · Free during preview

01 Ask for work you can check The prompt is the spec 2 benches · free 02 Read the whole diff Removed lines count too 2 benches · free 03 Keep secrets out of the code Keys leak through code, logs and errors 2 benches · first bench free 04 Treat every input as hostile Queries, pages, paths and redirects 2 benches · first bench free 05 Check who is asking Signed in is not the same as allowed 2 benches · first bench free 06 Check that it exists Packages and functions the model made up 2 benches · first bench free 07 Make tests able to fail A green test proves nothing on its own 2 benches · first bench free 08 Plan for when it breaks Timeouts, retries and honest errors 2 benches · first bench free