When I open the home page, I see almost nothing right out of the gate. There's no contrast at all. It's all tiny dark symbols on a vast black back background. After I let my eyes adjust for a bit, I see an empty timeline with absolutely no indication of how to load anything into it. I tried closing the timeline by clicking on the X in the upper right corner, but nothing happens.
Clicking on some faint squares in the upper right produces more nested panes. Contrary to the main pane they do have a menu (with labels, which is great). Clicking on the text menu produces uneditable example text in that pane. Hovering the mouse over the example text makes a plus icon appear. Clicking it creates a big red bar below the timeline in the original pane. I can change its size horizontally, but I can't find a way to enter any text.
I think someone who works with video editors a lot wouldn't be quite as confused by this user interface as I am. But a web app like this is probably aimed at casual users like me.
So my suggestions are:
a) More contrast! If you absolutely must do dark mode then you must also make everything on that black background big, fat and very bright, or people like me will think they just turned blind.
b) Better discoverability! All those tiny faint controls that appear only when the mouse is hovering over them are making it extremely hard for video editing newbies like me to understand what's going on.
c) Do some more testing. Besides not being able to enter any text, the plus icon in the text editor that normally produces those red bars stopped responding for me after a while. Refreshing the page brought it back to life.
I'm using Chrome on Mac with a not too great external monitor, which might make some of the contrast issues worse than it would appear to others.
Congrats to actually releasing something!