Fintech · Yuki

Wallet-as-a-service for African fintechs

One API that gives any fintech wallets, stablecoins, on/off ramps and KYC for its customers, normalising a patchwork of regional providers behind a single contract. 20,000+ requests a day.

Founder · CEO · Product lead

The problem

African fintechs had the customers and the licences, but not the crypto infrastructure. To offer a dollar stablecoin wallet they would have to build custody, chain integrations, ramps in several currencies and identity checks, each with its own provider, contract and failure modes. Most could not justify it.

My role

As founder, CEO and product lead I conceived Yuki as one API over all of it; my engineering team built it. At its peak it served more than 20,000 requests a day across fintech partners, including a neobank with more than 75,000 users.

How it works

Tenants, not users. Each business is an organisation with its own API keys and webhook endpoint. Every wallet belongs to an organisation and one of its customers, so partners never see each other's data.
One contract, many rails. Ramps, payouts, KYC links and chain access each come from a different regional or global provider. A provider layer normalises them, so a partner calls "create wallet", "fund" or "pay out" and never learns which rail did the work.
Safe to retry. Calls that create customers or move money carry idempotency keys, persisted before the provider is called, so a timeout followed by a retry can never create a customer or a payment twice.
Events back to the partner. On-chain and provider events are ingested by webhook, reconciled against the wallet's history and forwarded to the partner's own endpoint.
Drop-in front end. A server-driven embeddable widget lets partners ship wallet and KYC screens without building them, configured from the same API.

The hard part

No single integration was difficult. The difficulty was the seams: providers with different authentication, different retry semantics and different ideas of what "settled" means. Yuki's value was a normalisation layer strict enough that partners could build on it as if it were one system.

System

Custody: from encrypted keys to MPC and smart accounts

How Yuki's wallet custody evolved: envelope-encrypted keys to ship fast, then a composable V2 built around threshold signing and on-chain smart-contract wallets.

CustodyMPCWallets

System

A settlement network for fiat ramps

Large ramp orders broadcast to many liquidity providers, split into fillable pieces and settled through escrow, so African Web3 businesses can move volumes no single provider can carry.

SettlementLiquidityOn/off ramps

System

Identity, liveness and compliant onboarding

Biometric liveness and ID checks that work on entry-level Android phones, feeding KYC and AML gates for both the robo-advisor and the wallet platform.

KYCIdentityOnboarding

System

Stablecoin swaps and DEX pricing

Local-currency stablecoin swaps inside a mobile wallet, and an event-driven pricing library that quotes across dozens of exchanges from memory instead of hammering nodes.

DeFiStablecoinsPricing

Wallet-as-a-service for African fintechs

The problem

My role

How it works

The hard part

Related systems

Custody: from encrypted keys to MPC and smart accounts

A settlement network for fiat ramps

Identity, liveness and compliant onboarding

Stablecoin swaps and DEX pricing

The problem

My role

How it works

The hard part