Peak Money Backend¶
Peak Money is a consumer savings product offering high-yield savings accounts (7-10%+ APY target) and prize-linked savings. The backend is a shared platform layer serving both the consumer app (Peak Money) and the DeFi application (The Grove / FCM).
Payment Stack¶
The payment architecture integrates multiple specialized vendors, each handling a specific piece of the money flow.
| Vendor | Function | Status |
|---|---|---|
| Checkout.com | Credit card processing (Visa, Mastercard) | Production (test keys live, full approval pending) |
| Crossmint | Wallet abstraction, non-custodial wallets, KYC | Production (Ethereum deposits blocked) |
| Sardine | Fraud detection, KYC verification | Production |
| HiFi | Banking-as-a-service, fiat on/off-ramps | Production (replaced Noah) |
| Temporal | Workflow orchestration for multi-step transactions | Production |
| PYUSD0 | Stablecoin (PayPal USD on Flow EVM) | Production |
Authentication¶
- PassKey / WebAuthn for user authentication
- Email auth via Crossmint for initial onboarding
- Hybrid KYC flow integrating Sardine verification
How Money Flows¶
graph LR
U[User] -->|Credit Card / Apple Pay / ACH| CO[Checkout.com]
CO -->|Fiat processed| HF[HiFi Banking]
HF -->|Fiat to Stablecoin| FE[Flow EVM]
FE -->|PYUSD0 minted| CW[Crossmint Wallet]
CW -->|Deposit| PA[Prize Account / Vault]
U -->|Crypto deposit| CB[Cross-chain Bridge]
CB -->|USDC / USDT| CW
PA -->|Yield accrual| MV[Morpho ERC4626 Vault]
MV -->|Rewards| PA
Credit Card On-Ramp Flow (detailed)¶
- User initiates purchase in Peak Money app
- Sardine runs fraud check and KYC verification
- Checkout.com processes the credit card charge
- Fees deducted (~$0.49 on small transactions; minimum viable on-ramp ~$5)
- HiFi handles the fiat-to-crypto bridge
- PYUSD0 (PayPal USD on Flow EVM) arrives in user's Crossmint non-custodial wallet
- User can deposit PYUSD0 into Prize Account from self-custodial wallet — no transaction approval required
First Production Transaction
On April 7, 2026, the team successfully charged a credit card in production for the first time. A US-issued Visa card was charged $1.00, yielding 0.67 PYUSD0 on Flow EVM, which was deposited into the Prize Account end-to-end. Full production keys pending Visa/Mastercard approval.
Cross-Chain Deposits¶
- Users can deposit from external wallets (Ethereum, other chains)
- Cross-chain bridge handles token conversion
- Current blocker: Crossmint has not enabled Ethereum deposits in production (disabled Apr 3, 2026)
- Offchain Labs integration pending for proper deposit addresses
Prize Account Architecture¶
The Prize Account is a prize-linked savings product built on Morpho ERC4626 vaults on Flow EVM.
| Component | Description |
|---|---|
| Vault type | Morpho ERC4626 |
| Underlying asset | PYUSD0 (PayPal USD on Flow EVM) |
| Base yield | 4% guaranteed |
| Prize mechanism | Pooled prize draws from yield surplus |
| Withdrawal | Instant when vault has liquidity |
Vault Liquidity Dependency¶
Known Risk: Vault Liquidity
Users can be unable to withdraw when the vault operator has insufficient liquidity. The vault issues shares to depositors, and redemption fails (error code 306) when liquidity is depleted. The only current mitigation is manual escalation to the vault operator to top up funds. Monitoring and alerting similar to the wFLOW vault AMM is being built.
Key Integration Points¶
Temporal Workflows¶
Multi-step financial transactions are orchestrated via Temporal. This handles:
- Credit card processing to fiat conversion to crypto minting to wallet deposit as a single atomic workflow
- Retry logic for failed steps
- Compensation (rollback) logic for partial failures
- Audit trail for compliance
Sardine (Fraud and KYC)¶
- Pre-transaction fraud scoring
- Hybrid KYC flow (in-app identity verification)
- API and pixel subdomain support (PR #1101 merged)
Customer.io (Lifecycle Marketing)¶
- Waitlist management (~6,000 waitlisted, ~346 accepted as of Apr 7)
- Drip campaigns for onboarding stages
- Event-triggered communications based on user actions (deposits, KYC completion, etc.)
Architecture Principles¶
The backend is designed with AI-native development in mind:
- Local development is first-class — full environment runs in Docker containers
- Backwards and forwards compatible APIs — agents can safely modify and test without breaking production
- Sandboxed agent execution — AI coding agents can run in isolated Docker environments
- Feature-flagged everything — staged rollouts for all changes
Economics¶
| Metric | Value |
|---|---|
| Card processing fee | ~2.9% + $0.30 per transaction |
| Minimum viable on-ramp | ~$5 (below this, fees exceed principal) |
| Infrastructure cost target | $750K Y1, scaling to $2.8M Y3 |
| Per-user cost | $0.10/month infra, $0.50/month support |
| Signup target | <5 min to first deposit |
| KYC completion target | 60%+ |
| Uptime target | 99.9% |
Team¶
| Person | Role |
|---|---|
| Bart Bobnis | Engineering Lead (Director) |
| Corey Humeston | Backend Engineer |
| Felipe Ribeiro | Frontend Engineer |
| Ford | Engineer |
| Brady Bhatt | Engineer |
| Oleg Smetanin | Backend Engineer |
This section needs enrichment from the engineering team
Detailed API documentation, database schema, Temporal workflow definitions, and deployment procedures should be added by the Consumer App Pod. This page was derived from meeting dossiers and standup notes.