TyreStack
Software and websites for mobile tyre fitters.
2026
Eleven pieces of psychology we design with, and where to see them
Deep diveA field guide to the design psychology behind our apps and sites: the published source for each idea, the screen where we used it, and the dark-pattern version of it we will not ship.
An undo button that tells the truth
Field notesA TyreStack fitter now gets 30 seconds to take back a Done tap, but only while undoing it would not falsify the stock or money records. The same audit found our board plotting jobs at invented places.
Ten thousand worlds before the first real fitter
Deep diveTyreStack's scheduler had no customers yet, so before launch we built an audited oracle and threw ten thousand generated worlds of bookings, holds and late vans at it, comparing the old engine and the new one call for call.
The outage that moved us to Cloudflare
Decision recordAt 06:02 a Google Cloud zone stopped answering and took two products, both still in beta, with it. Our own review said stay and pay for high availability. By 15:45 we had left anyway. Here is the reasoning, and the objections to it.
24 files we are not allowed to edit
Deep diveEd proved his scheduling engine against ten thousand simulated worlds. TyreStack imports it unchanged, locks 24 files to his exact bytes with a hash, and the gate fails the moment one of them differs.