Case study · Wallets · Prepaid · Entitlements

Wallets and prepaid usage

I scoped the Wallet & Entitlements MVP, a board-level bet on AI-platform billing. Then I built the prepaid rollover and expiration controls, fixed the issues found at launch, and wrote the public API docs.

The problem

AI platforms bill their customers through credits: buy up front, draw down as you go. Maxio needed to compete with Stripe, Orb and Metronome for that business. A full rebuild of prepaid billing would have taken too long.

How I approached it

I wrote the MVP brief and scoped it to wallets at the subscription level, so the foundation could ship quickly alongside the existing prepaid billing instead of replacing it. Then I worked through the prepaid gaps customers ran into: how units roll over, when they expire, and what the usage screens show.

What I delivered

Wallets · Prepaid · Entitlements

Period: Jun – Oct 2026
Role: PM and lead implementer
Stack: Rails · React · OpenAPI
Largest PR: 59 commits

Line item	Detail
MVP brief	Scoped the Wallet & Entitlements MVP to subscription-level wallets, so the base for AI-platform billing could ship without replacing prepaid billing.
Custom rollover and expiration	Let customers choose how prepaid units roll over and when they expire, with dates that stay correct through trials, billing-date changes and renewals. It went through a dozen review rounds, combining automated review, independent review and hands-on testing.
Expiration UX	Replaced a confusing set of radio buttons with one date field and presets, and added a warning when someone picks a term-end expiration for a subscription that has no term.
Usage widget and ledger	Fixed the display of fractional units, marked fully consumed purchases as Used, reported one-time and recurring draws separately, and made the purchase drawer default to the right type.
Wallet data	Returned the applied rate and metering window on wallet transactions, used the site's time zone, counted grants that expire one after another, and added clear failure codes for purchases at signup.
Developer docs	Wrote the public Wallets, Entitlements and Hybrid Pricing API docs on developers.maxio.com: wallet products, purchases, meter pairing and posted balances.

ResultA prepaid and wallets product that customers can configure and trust, launched quickly enough to compete for AI-platform billing, with docs that integrators can build against.

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