Projects
Every order counted once
Greenlot is the system underneath a business: its online shop, its till, its payments and its books all plug into it, and it keeps them in exact agreement. Nothing is applied until its signature checks, the original is kept byte for byte, and every change lands once, in one PostgreSQL transaction, so a copy, an outage or revoked access can never leave anything half-done. This one isn’t a recording: start it and Greenlot’s own backend and a PostgreSQL database load into this tab, so every failure you press runs through the real pipeline on your machine.
P.S. Ten secrets are hidden in it. Can you find them all?
Two hundred orders at once
Black Friday sends 200 signed orders from both shops at once, with copies and edits that arrive before their own order mixed in. They come in faster than one worker can take them, so a queue builds and drains, drawn from the stored jobs as it happens, and every order still passes the same checks as a single one. The rate and the time are measured in the tab that runs it, so yours will differ from this recording. The link below loads the same 200 orders, from the same seed.
Under the hood
Every message keeps the bytes it arrived with, its signature result and each attempt the worker made, with the waits between them drawn to scale. A copy can be compared with its original, byte for byte. Each change is one PostgreSQL transaction, and every statement it ran can be read with its time. The queue and the worker are charted from the stored jobs, and a stock conflict the rules can’t settle waits in the console for a person’s decision. And 435 automated tests check it, every failure in the demo among them.
