Deck: A Kanban App That Lives Inside Nextcloud, With Known Scaling Limits

What Deck Solves and Who It Is For

Deck is a kanban board application that runs as a Nextcloud app. It solves the problem of managing tasks and projects without leaving the Nextcloud ecosystem. The target user is a Nextcloud instance owner, whether an individual or a team, who wants a Trello-like board for personal planning or team organization. The README lists features such as cards, labels, markdown notes, file attachments, comments, and an activity stream. It also integrates with the Nextcloud Circles app for sharing. This is not a standalone tool; it is an add-on that extends an existing Nextcloud installation. If you do not use Nextcloud, Deck is not for you.

How Deck Works: Cards, Stacks, and Nextcloud Integration

The repository is a Nextcloud app, meaning it hooks into the Nextcloud server's PHP backend and JavaScript frontend. The data model is the classic kanban structure: boards contain stacks, stacks contain cards. Cards hold tasks, and you can add notes in markdown, assign labels, attach files, and comment. The file attachment feature likely uses Nextcloud's file storage, as the README mentions embedding files in markdown descriptions. The activity stream tracks changes, which is a standard Nextcloud feature. The integration with Circles means sharing boards can use Nextcloud's existing circle system, which is a way to group users. The REST API documentation is hosted at deck.readthedocs.io, indicating that external clients can interact with boards programmatically. The mobile apps for Android and iOS are separate projects, so the core app is the web interface within Nextcloud.

Getting Deck Running: Installation and Build Commands

Installation is straightforward for a Nextcloud admin. The README states the app can be installed through the app store within Nextcloud, or you can download a release from the release page. For development, you need Node.js and Composer. The build steps are: run `composer install --no-dev` for PHP dependencies, then `npm ci` for JavaScript dependencies, then `npm run dev` for a development build, `npm run watch` to watch for changes, or `npm run build` for production. For a quick development environment, the README shows a Docker command that mounts the Deck source into a Nextcloud dev container: `docker run --rm -p 8080:80 -v $PWD:/var/www/html/apps-extra/deck ghcr.io/juliushaertl/nextcloud-dev-php81:latest`. This is useful for testing changes without a full Nextcloud setup. The README also mentions a devcontainer for VS Code and GitHub Codespaces, which auto-installs dependencies.

The Performance Limitation Is Real and Documented

The most important thing to know about Deck is its performance warning. The README has a section titled 'Performance limitations' that says, 'Deck is not yet ready for intensive usage.' It gives a concrete example: a user with access to 13 boards, each with 100 cards and each card with 5 attachments, would generate 6500 database queries for file-related queries alone. That will increase page loading time significantly. This is a genuine limitation, not a vague concern. The README says improvements on the Nextcloud server and Deck itself will improve the situation, but as of the latest release, this is a known issue. For any team planning to use Deck for large projects, this should be a red flag. The number of queries is not just a minor slowdown; it can make the app nearly unusable at scale.

Alternatives: Trello and Dedicated Kanban Tools

The obvious alternative is Trello, which Deck is explicitly compared to. Trello is a hosted service, so you do not need to manage a server. It has a polished interface and handles large boards without the database query problem, because it is a dedicated application with optimized data access. The difference in approach is fundamental: Trello is a standalone SaaS, while Deck is a plugin inside a general-purpose file sharing and collaboration server. That means Deck benefits from tight integration with Nextcloud files, comments, and user management, but it inherits the performance characteristics of the Nextcloud database layer. Other alternatives include self-hosted kanban tools like Wekan or Focalboard, which are also standalone and may have better performance, but they do not have the same native file integration with Nextcloud. For a team that lives in Nextcloud, Deck's integration is a strong draw, but for a team that needs scale, a dedicated tool is safer.

Maintenance and Upgrade Costs

Deck is actively maintained, with recent releases including v1.19.0-beta.2, v1.18.4, and v1.17.5, all pushed on the same date, which suggests a regular release cycle. The app is licensed under AGPL-3.0, which means if you modify and distribute it, you must share your changes under the same license. For internal use, this is not a burden. Upgrade cost is tied to Nextcloud versions; since Deck is a Nextcloud app, you must ensure compatibility with your Nextcloud server version. The README does not specify a compatibility matrix, so you need to check the app store or release notes for that. The development setup involves Composer and npm, so maintaining a custom build requires keeping those dependencies updated. For most users, installing from the Nextcloud app store means upgrades are handled by the Nextcloud admin interface, which is low effort.

Editorial conclusion

Adopt Deck if your team already runs Nextcloud and needs a simple, self-hosted kanban board with file attachments, comments, and activity tracking, and if your board and card counts stay low. Do not adopt it for large projects with hundreds of cards and attachments per board, because the README explicitly warns of 6500 database queries in a moderate scenario, which will slow page loads. Before committing, verify your Nextcloud server version compatibility and run a load test with your expected board and card numbers, and check whether the Circles integration covers your sharing needs. If scaling is a priority, consider a dedicated kanban tool that does not sit inside Nextcloud, but be prepared to lose the tight file and sharing integration.

Frequently asked questions

Official sources

1. Official documentation
2. Official README
3. Project repository
4. Release notes