> ## Documentation Index
> Fetch the complete documentation index at: https://rain-sandbox-trial.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Platform Architecture
> The four layers every Rain product runs on: your tenant, compliance, customer records, and the ledger.
Rain is one platform with several products built on top of it, not a set of
separate services that happen to share a domain name. Every product you build
runs through the same shared architecture.
## The stack
The diagram below traces a single request from your tenant to the event it
triggers. Read it top to bottom.
## What each layer does
Each layer, and where it's documented:
| Layer | What it holds |
| :-------------------------------------------------- | :------------------------------------------------------------------------------ |
| [Your tenant](/docs/managing-subtenants) | Your program, plus any subtenants running their own programs underneath yours. |
| [Verification and screening](/docs/compliance) | The gate. Nothing downstream unlocks until the relevant check passes. |
| [Users and companies](/docs/customers-and-identity) | The customer records every product references. One record, many products. |
| [Products](/docs/products-at-a-glance) | Cards, accounts and ramps, global payouts, wallets and collateral, and rewards. |
| [Ledger](/docs/ledgering-system) | Double-entry accounting for every balance change, in accounts and books. |
| [Webhook events](/docs/webhooks) | One event stream for every state change across every product. |
## Why Rain arranges the stack this way
Two choices in this architecture matter for how you build:
### Compliance sits above the products, not inside each one
Verification is a gate you pass through, not a feature of the cards product. That's why
the gate clears a customer for one capability and not another: it grants
access per capability. Cards KYC or KYB approval unlocks card issuance.
Payments verification unlocks money movement and virtual accounts. Clearing
one does not clear the other. See [Payments compliance](/docs/payments-compliance)
for how compliance gates the payments side.
### Every product shares one ledger, so they reconcile against each other
A card authorization and an inbound fiat deposit for the same customer land in the same
account, in different books. You reconcile once, against one source, rather than
stitching together per-product balances.
## What's next
Tenants, companies, users, and how to map Rain records onto your own.
Pick which product to start with.
The two verification pipelines and what each one unlocks.
Accounts, books, and how double-entry ledgering works at Rain.