Not at all. Trello is quite snappy and back when I first started using it in 2013, it was remarkably so compared to all other similar tools I'd seen.

To add to other people's anecdotal evidence, Trello is painfully slow for the board I use the most. Perhaps I over-use it - I have 27 lists, the longest of which has some 1500 cards. But it's slow to the point where Chrome asks if I want to kill the tab at least once every 2 days.

It works fine for other boards, so I assume it wasn't built with so many lists+cards in mind. But the fact it, it can be slow, almost unusable, at least for certain use cases.

Do you have any data to back that up? I rarely hear people saying Trello slow, usually the opposite.

I'm with you, Trello was super slow for some larger projects that I used it with. I posted this in my own comment, but it makes sense here, too [1]. Not sure if the performance problems were related to the backend stack, though. My impression is that the api was just written really inefficiently.

[1]: https://blog.fogcreek.com/we-spent-a-week-making-trello-boar...

Anecdotally, Trello is the most performant large scale web app I use.

From a user experience perspective it is freaky fast at updating other clients.