docs: update architecture.md (#3488)

docs/docs/developer/architecture.md

@@ -4,38 +4,107 @@ sidebar_position: 1
 
 # Architecture
 
+Immich uses a traditional client-server design, with a dedicated database for data persistence. The frontend clients communicate with backend services over HTTP using REST APIs.
+
 ## High Level Diagram
 
 ![Immich Architecture](./img/app-architecture.png)
 
-## Technology
+The diagram shows clients communicating with the server via REST, as well as the flow of database between backend services.
+
+## Clients
+
+Immich has three main clients:
+
+1. Mobile app - Android, iOS
+2. Web app - Responsive website
+3. CLI - Command-line utility for bulk upload
+
+:::info
+All three clients use [OpenAPI](./open-api.md) to auto-generate rest clients for easy integration. For more information about this process, see [OpenAPI](./open-api.md).
+:::
+
+### Mobile App
+
+The mobile app is written in [Flutter](https://flutter.dev/). It uses [Isar Database](https://isar.dev/) for a local database and [Riverpod](https://riverpod.dev/) for state management.
+
+### Web Client
+
+The web app is a [TypeScript](https://www.typescriptlang.org/) project that uses [SvelteKit](https://kit.svelte.dev) and [Tailwindcss](https://tailwindcss.com/).
+
+### CLI
+
+The CLI is a [TypeScript](https://www.typescriptlang.org/) project that parses command line arguments to programmatically upload/import assets to an Immich server. See [Bulk Upload](/docs/features/bulk-upload.md) for more information about its usage.
+
+## Server
+
+The Immich backend is divided into several services, which are run as individual docker containers.
+
+1. `immich-server` - Handle and respond to REST API requests
+1. `immich-microservices` - Execute background jobs (thumbnail generation, metadata extraction, transcoding, etc.)
+1. `immich-machine-learning` - Execute machine learning models
+1. `postgres` - Persistent data storage
+1. `redis`- Queue management for `immich-microservices`
+1. `typesense`- Specialized database for search, specifically with vector comparison features
+
+### Immich Server
+
+The Immich Server is a [TypeScript](https://www.typescriptlang.org/) project written for [Node.js](https://nodejs.org/). It uses the [Nest.js](https://nestjs.com) framework, with [TypeORM](https://typeorm.io/) for database management. The server codebase also loosely follows the [Hexagonal Architecture](<https://en.wikipedia.org/wiki/Hexagonal_architecture_(software)>). Specifically, we aim to separate technology specific implementations (`infra/`) from core business logic (`domain/`).
+
+#### REST Endpoints
+
+The server is a list of HTTP endpoints and associated handlers (controllers). Each controller usually implements the following CRUD operations:
+
+- `POST` `/<type>` - **Create**
+- `GET` `/<type>` - **Read** (all)
+- `GET` `/<type>/:id` - **Read** (by id)
+- `PUT` `/<type>/:id` - **Updated** (by id)
+- `DELETE` `/<type>/:id` - **Delete** (by id)
+
+#### DTOs
+
+The server uses [Domain Transfer Objects](https://en.wikipedia.org/wiki/Data_transfer_object) as public interfaces for the inputs (query, params, and body) and outputs (response) for each endpoint. DTOs translate to [OpenAPI](./open-api.md) schemas and control the generated code used by each client.
+
+### Microservices
+
+The Immich Microservices image uses the same `Dockerfile` as the Immich Server, but with a different entrypoint. The Immich Microservices service mainly handles executing jobs, which include the following:
+
+- Thumbnail Generation
+- Metadata Extraction
+- Video Transcoding
+- Object Tagging
+- Facial Recognition
+- Storage Template Migration
+- Search (Typesense synchronization)
+- Sidecar (see [XMP Sidecars](/docs/features/xmp-sidecars.md))
+- Background jobs (file deletion, user deletion)
+
+:::info
+This list closely matches what is available on the [Administration > Jobs](/docs/administration/jobs.md) page, which provides some remote queue management capabilities.
+:::
+
+### Machine Learning
 
-Immich is a full-stack [TypeScript](https://www.typescriptlang.org/) application, with a [Flutter](https://flutter.dev/) mobile app.
+The machine learning service is written in [Python](https://www.python.org/) and uses [FastAPI](https://fastapi.tiangolo.com/) for HTTP communication.
 
-### Mobile
+All machine learning related operations have been externalized to this service, `immich-machine-learning`. Python is a natural choice for AI and machine learning. It also has some pretty specific hardware requirements. Running it as a separate container makes it possible to run the container on a separate machine, or easily disable it entirely.
 
-- [Flutter](https://flutter.dev/)
-- [Riverpod](https://riverpod.dev/) for state management.
+Machine learning models are also quite _large_, requiring _quite a bit_ of memory. We are always looking for ways to improve and optimize this aspect of this container specifically.
 
-### Web
+### Postgres
 
-- [SvelteKit](https://kit.svelte.dev/)
-- [Tailwindcss](https://tailwindcss.com/)
+Immich persists data in Postgres, which includes information about access and authorization, users, albums, asset, sharing settings, etc.
 
-### Server
+:::info
+See [Database Migrations](./database-migrations.md) for more information about how to modify the database to create an index, modify a table, add a new column, etc.
+:::
 
-- [Node.js](https://nodejs.org/)
-- [Nest.js](https://nestjs.com/)
-- [TypeORM](https://typeorm.io/) for database management.
-- [Jest](https://jestjs.io/) for testing.
-- [Python](https://www.python.org/) for Machine Learning.
+### Redis
 
-### Database
+Immich uses [Redis](https://redis.com/) via [BullMQ](https://docs.bullmq.io/) to manage job queues. Some jobs trigger subsequent jobs. For example, object detection relies on thumbnail generation and automatically run after one is generated.
 
-- [PostgreSQL](https://www.postgresql.org/)
-- [Redis](https://redis.io/) for job queuing.
-- [Typesense](https://typesense.org/) for search.
+### Typesense
 
-### Web Server
+Immich synchronizes some of the Postgres data into Typesense, so it can execute vector related queries in order to implement certain features including, facial recognition and CLIP search.
 
-- [NGINX](https://www.nginx.com/) for internal communication between containers and load balancing when scaling.
+<!-- - [NGINX](https://www.nginx.com/) for internal communication between containers and load balancing when scaling. -->

docs/docs/developer/directories.md

@@ -0,0 +1,22 @@
+---
+title: Directories
+---
+
+# Repository Folder Structure
+
+Our [GitHub Repository](https://github.com/immich-app/immich) is a [monorepo](https://en.wikipedia.org/wiki/Monorepo) and includes the following folders:
+
+| Folder              | Description                                                          |
+| :------------------ | :------------------------------------------------------------------- |
+| `.github/`          | Github templates and action workflows                                |
+| `.vscode/`          | VSCode debug launch profiles                                         |
+| `cli/`              | Source code for the work-in-progress CLI rewrite                     |
+| `docker/`           | Docker compose resources for dev, test, production                   |
+| `design/`           | Screenshots and logos for the README                                 |
+| `docs/`             | Source code for the [https://immich.app](https://immich.app) website |
+| `machine-learning/` | Source code for the `immich-machine-learning` docker image           |
+| `misc/release/`     | Scripts for version pumps and draft releases                         |
+| `mobile/`           | Source code for the mobile app, both Android and iOS                 |
+| `nginx/`            | Source code for the `immich-proxy` docker image                      |
+| `server/`           | Source code for the `immich-server` docker image                     |
+| `web/`              | Source code for the `immich-web` docker image                        |