```mermaid
flowchart LR
  subgraph Mgnt API
    A1(Content Mgmt)
    A2(System Params)
  end

  subgraph App API
    B1(Ad Placement)
    B2(Video Listing)
  end

  subgraph Datastores
    MSQL[(MySQL)]
    MONGO[(MongoDB)]
    REDIS[(Redis)]
  end

  A1-->MSQL
  A1-->MONGO
  A1-->REDIS

  B1-->REDIS
  B2-->MONGO

  App API-->REDIS
```