Xerovan

Xerovan is an app that holds your crypto and gives you a real Visa card to spend it, in a shop, online, anywhere cards are taken. You can also earn interest on assets you're not using and swap one currency for another.

Businesses can use it too: give staff a card, set a limit, and see what they spent.

Holding digital currency is easy. Spending it isn't. Normally you sell it on an exchange, move the money to a bank and wait a few days, by which point whatever you needed it for has passed.

Card networks only move real money. So the moment someone taps at a till, their stablecoins have to be sold for actual dollars and settled in under two seconds. Crypto networks settle whenever they settle, each with their own fees, delays and failure modes, and the money is spread across ten of them. Send to the wrong one and it's gone for good.

I led the side of the product that handles the money. The card was the centre of it: applying, getting approved, activating, spending limits, monthly statements, ordering the physical card and sharing one with a family member. On top of that came the business version, where a company can set rules for what staff can spend on and require a receipt.

Swapping used to mean leaving for an exchange and coming back. I rebuilt it so it happens inside the app, across six networks, in a few taps. Savings earn interest, and the rate you see is read live, not a number someone typed in once and forgot about.

A lot of the work was simply keeping it running: making sure that when one piece breaks it doesn't take the whole app down, and that problems are caught before users ever see them.