At season end your cash and all level and XP progression reset, on every track including Career, and every blueprint you paid for goes with them. Leftover cash converts to Gold Bars automatically. Gold Bars and cosmetics bought with them are kept.
The authority is the in-game Gold Exchange text: progression and cash reset at the end of a major update cycle, and the date will be announced ahead of time. A developer forum post from March 2026 saying XP does not reset is out of date.
Beta progress did not carry into Early Access, and BULKHEAD's FAQ confirms pre-alpha cash did not carry into the full game. The FAQ does not mention beta progress directly, so treat that part as well supported rather than officially stated.
BULKHEAD also says each season gets a different XP curve and item order. Do not plan unlocks beyond the current season.