Internal usage is basically Cloud Unit Economics: https://www.finops.org/wg/introduction-cloud-unit-economics You treat infra teams as providers and price-in their services. For example you may price Compute team by "selling" vCPUs, DB team by selling GB stored per month and product team per business transactions. Each team builds on top of each other and buys a service from their downstream provider. Like product team buys DB storage, DB team buys vCPU to run DB etc. If you price in these internal resources (rate cards) and track usage you can attribute cost to each team based on their consumption. These internal bills together equals to the total company wide AWS bill. This not just creates accountability for teams but you can also do margin analysis and tell if certain team's product is profitable. Engineers can also plan future services and architecture by estimating cost like, new service will store 1TB/day which will cost X and then business/PMs can make decision based on it. It's a also a great way to optimize cloud cost beyond obvious isolated things like upgrading instance types as it tells you where optimization needs to happen, which provider need to lower their cost to increase margins.
