Trello software and system design

https://stackoverflow.com/questions/10505431/how-does-trello-show-history-so-quickly?noredirect=1&lq=1
Trello stores all of the cards in one collection. The collection is sharded on the card's board id.

https://stackoverflow.com/questions/12969344/how-does-trello-store-data-in-mongodb-collection-per-board

I'm on the Trello team. We use an Actions collection in our MongoDB instance, with a compound index on the ids of the models to which it refers (a Card is a model, and so is a Member) and the date when the action was performed. No fancy caching or anything, except inasmuch as the index and recently used documents are kept in memory by the DB. Actions is by far our biggest collection.

It is worth mentioning that most of the data needed to display an action is stored denormalized in the action document, so that speeds things up considerably.

https://www.sitepoint.com/fullstack-javascript-trello-clone/

https://blog.fogcreek.com/the-trello-tech-stack/

{
    "model"=>{
        "id"=>"5204523d8d3432ff1a000a60",
        "name"=>"#BOARD",
        "desc"=>"",
        "descData"=>nil,
        "closed"=>false,
        "idOrganization"=>"53aaf6e5309dc12a75111fbf",
        "pinned"=>false,
        "url"=>"https://trello.com/b/ABdAaJeO/board",
        "shortUrl"=>"https://trello.com/b/ABdAaJeO",
        "prefs"=>{
            "permissionLevel"=>"org",
            "voting"=>"disabled",
            "comments"=>"members",
            "invitations"=>"members",
            "selfJoin"=>false,
            "cardCovers"=>true,
            "calendarFeedEnabled"=>true,
            "background"=>"river",
            "backgroundColor"=>nil,
            "backgroundImage"=>"https://d2a2fgsv6pobq6.cloudfront.net/images/backgrounds/river/full.jpg",
            "backgroundImageScaled"=>[
                {
                    "width"=>2400,
                    "height"=>1600,
                    "url"=>"https://d2a2fgsv6pobq6.cloudfront.net/images/backgrounds/river/large.jpg"
                },
                {
                    "width"=>1024,
                    "height"=>683,
                    "url"=>"https://d2a2fgsv6pobq6.cloudfront.net/images/backgrounds/river/medium.jpg"
                },
                {
                    "width"=>320,
                    "height"=>213,
                    "url"=>"https://d2a2fgsv6pobq6.cloudfront.net/images/backgrounds/river/small.jpg"
                }
            ],
            "backgroundTile"=>false,
            "backgroundBrightness"=>"dark",
            "canBePublic"=>true,
            "canBeOrg"=>true,
            "canBePrivate"=>true,
            "canInvite"=>true
        },
        "labelNames"=>{
            "green"=>"",
            "yellow"=>"Тесты",
            "orange"=>"frontend",
            "red"=>"bugs",
            "purple"=>"инфраструктура",
            "blue"=>"backend",
            "sky"=>"проектирование",
            "lime"=>"гипотеза",
            "pink"=>"",
            "black"=>""
        }
    },
    "feature"=>{

    }
}