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Layered Libraries

The 'L' of MonoLISA.

MonoLISA achieves separation of concerns (SoC) with:

  • Layers to separate technical concerns.

  • Libraries to separate the concerns of actors.

Layers​

Define a layer for each high-level technical concern.

Domain (business rules), API (endpoints), database (repositories), and integration (to downstream services) are examples of backend layers.

Create a folder for each layer in the libs folder. For example:

libs
- domain
- api
- db
- integration

Libraries​

Create libraries for actors within the layers.

Actors​

An actor is a role a user plays the moment they act on the system.

For example, if you are developing an email app, the user could be seen as an ‘inbox viewer’ actor when they view the inbox and a ‘draft editor’ when they write an email.

libs
- domain (layer)
  - inbox (lib)
  - draft-editor (lib)
- api (layer)
  - inbox (lib)
  - draft-editor (lib)
etc.