# Architecture Overview

Flint vaults run on Lagoon Finance, a full-stack vault management system built around the ERC-7540 standard. It handles NAV-based settlement, role-based permissions, configurable fees, and asynchronous deposit and redemption flows. Contracts are written in Solidity, deployed on EVM chains, and audited by three independent firms.

## How the stack is layered

```
User (USDC)
    |
    v
Lagoon Vault (ERC-7540)       <- smart contract layer
    |
    +-- Deposit Silo           <- pending deposits sit here until settlement
    +-- Redemption Silo        <- pending shares sit here until settled
    |
    v
lend.xyz / opLend             <- RWA bond origination protocol
    |
    v
Real Estate Operations         <- EUR-denominated debt positions
```

## Core concepts

| Concept                 | What it means                                                                        |
| ----------------------- | ------------------------------------------------------------------------------------ |
| Asynchronous settlement | Deposits and redemptions are queued first, then settled at a defined valuation point |
| NAV                     | The price-per-share used at settlement, not at request time                          |
| Valuation               | Proposed by the Valuation Provider, accepted by the Curator before it's applied      |
| Settlement              | The Curator batches pending requests and processes them at the approved NAV          |
| Guardrails              | On-chain price-per-share bounds that block abnormal valuation changes                |
| Access control          | Whitelist, blacklist, and sanctions list options for compliance                      |

***

*Continue reading:*

* [Deposit & Redemption Flows](/flintrwa-docs/technical-architecture/deposit-redemption-flows.md)
* [Vault Valuation](/flintrwa-docs/technical-architecture/vault-valuation.md)
* [Roles](/flintrwa-docs/technical-architecture/roles.md)
* [Fees](/flintrwa-docs/technical-architecture/fees.md)
* [Access Control](/flintrwa-docs/technical-architecture/access-control.md)
* [Upgradability](/flintrwa-docs/technical-architecture/upgradability.md)


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