Add ownership information and guidance for improving collaboration of features...

Add ownership information and guidance for improving collaboration of features involving Editor Extensions

.gitlab/CODEOWNERS

@@ -128,7 +128,7 @@
 /content/handbook/engineering/development/dev/ @timzallmann
 /content/handbook/engineering/development/dev/create/ @dsatcher
 /content/handbook/engineering/development/dev/create/code-creation/ @mnohr @jordanjanes
-/content/handbook/engineering/development/dev/create/editor-extensions.md @dashaadu @kisha.mavryck
+/content/handbook/engineering/development/dev/create/editor-extensions/ @dashaadu @kisha.mavryck
 /content/handbook/engineering/development/dev/create/remote-development/ @adebayo_a
 /content/handbook/engineering/development/dev/manage/ @wortschi @m_gill @mksionek
 /content/handbook/engineering/development/dev/foundations/ @m_gill @samdbeckham @wortschi

content/handbook/engineering/development/dev/create/editor-extensions.md → content/handbook/engineering/development/dev/create/editor-extensions/_index.md

@@ -42,6 +42,12 @@ Additionally to our main team's slack channels, each extension/project we work o
   - JetBrains extension: [#f_jetbrains_plugin](https://gitlab.slack.com/archives/C02UY9XKABH)
   - Neovim extension: [#f_neovim_plugin](https://gitlab.slack.com/archives/C05BF7L6PEX)
 
+## Cross-group ownership and boundaries
+
+Editor extensions systems host features and modules owned by different groups.
+
+The [Ownership and Boundaries](/handbook/engineering/development/dev/create/editor-extensions/ownership/) page provides clarity and a clear expectation between all parties who author/maintain features in our systems.
+
 ## Group processes
 
 Our group processes are documented in this section.

content/handbook/engineering/development/dev/create/editor-extensions/ownership.md

+---
+title: "Ownership and boundaries - Editor Extensions"
+description: This page provides clarity and a clear expectation between all parties who author/maintain features in editor extensions systems.
+---
+
+## Context
+
+Multiple groups contribute to features exposed through our editor extensions. This can create ambiguity regarding ownership and maintenance responsibilities. This document outlines an agreed-upon approach for consistent ownership attribution, aligning expectations and improving efficiency among all involved parties. 
+
+Owning a system part means being responsible for feature development, bug-fixes, and general maintenance of the affected part. Ideally, a team has maintainers in the system part they own to be more independent of the editor extensions team, but this is not a strict requirement.
+
+## System overview
+
+Currently, the external features being integrated via our Editor Extensions follow this architecture:
+
+* UI component built on [gitlab-ui](https://gitlab.com/gitlab-org/gitlab-ui)
+* Integration with Editors: Webview
+  * Webview is a web page shown in the editor
+* Integration with Editors: Business logic
+  * Business logic represents the editor-specific integration (e.g. TypeScript and VS Code Extension API, Kotlin and JetBrains Plugin API)
+
+## Legacy Ownership model
+
+Currently used by **Duo Chat**:
+
+| System part | Group responsible |
+| ------ | ------ |
+|    [Chat UI component in `gitlab-ui`](https://gitlab.com/gitlab-org/gitlab-ui/-/tree/main/src/components/experimental/duo/chat)     |   **AI-Powered:Duo Chat** group.     |
+|    VS Code - [Chat Webview](https://gitlab.com/gitlab-org/gitlab-vscode-extension/-/tree/main/webviews/vue2/gitlab_duo_chat) (web page)    |     **AI-Powered:Duo Chat** group with support from **Create:Editor Extensions** group     |
+|    VS Code - [Chat business logic](https://gitlab.com/gitlab-org/gitlab-vscode-extension/-/tree/main/src/common/chat?ref_type=heads) (extension)     |  **Create:Editor Extensions** group      |
+|   JetBrains - [Chat Webview](https://gitlab.com/gitlab-org/editor-extensions/gitlab-jetbrains-plugin/-/tree/main/webview) (web page) |   **AI-Powered:Duo Chat** group with support from **Create:Editor Extensions** group      |
+| JetBrains - [Chat business logic](https://gitlab.com/gitlab-org/editor-extensions/gitlab-jetbrains-plugin/-/tree/main/src/main/kotlin/com/gitlab/plugin/chat) (plugin) | **Create:Editor Extensions** group  |
+
+## Ownership model for features implemented in Language Server
+
+Currently used by **Duo Workflow** and soon to be used by **Duo Chat**.
+
+| System part | Group responsible |
+| ------ | ------ |
+|    UI Component     |   Group owning the UI component     |
+|    LS webview & plugin    |    Group owning the UI component with support from **Create:Editor Extensions** group  |
+|    VS Code integration     |    **Create:Editor Extensions** group    |
+|   JetBrains integration |    **Create:Editor Extensions** group    |
+| Visual Studio integration | **Create:Editor Extensions** group |
+
+## Process of notifying others
+
+* When a team starts working on a feature that will require Editor Extensions support:
+  * PM/EM will notify **Create:Editor Extensions** group's PM/EM - this allows the team to forecast the capacity necessary to support in the near future
+* When the UI of the feature is ready:
+  * the authoring team opens an integration MR
+    * The **Create:Editor Extensions** group will assign an engineer to take over the MR and complete integration