The first full 3 vs 3 match
The morning after the first line of code, a whole match ran from countdown to results — every courier driven by the computer.
From the developer 2 min read Milestone date: Posted

The first line of VELTRAIL’s code was written on the evening of 27 September. By the next morning there was a match to watch.
Two more arenas
At 09:45 on 28 September the second arena, Weaving Yard, got its first draft: raised decks crossing over lanes, where rails on different levels never connect. At 09:53 Cloud Wharf followed, with a ring of quays as the safe way round and two drawbridges as shortcuts. Together with Coil Garden from the night before, these are the three arenas of version 1.0 — much tuned since, but the same places.

From countdown to results
Between 10:47 and 10:51 five parts of the game came together: the arenas, the bots, the menus, the online code and the match itself on screen. For the first time a complete three-against-three match ran on screen, from the countdown through three rounds to the results — with every one of the six couriers driven by the computer. In VELTRAIL, bots play by exactly the same rules and send the same kind of commands as a person; even the hardest of them gets no faster pulses and can’t see through walls.
A match also has to clean up after itself. To check that, a test played twelve complete matches back to back, and the number of objects in memory stayed flat from the third match on. It is the kind of result nobody notices when it works — and everybody notices on the tenth match of an evening when it doesn’t.
By the evening
At 17:28 the tutorial and the challenges joined the game, and at 17:32 the key-moment replay: the short clip after a match that shows the moment that decided it. Less than a day after the first line of code, the shape of version 1.0 was in place.
The eight days that followed went into everything that makes a shape into a game you can ship: playing on a real phone, online play against a real server, balance, safety tools, and the store.