I know we have a good number of these posts going around at the moment but I wanted to add one more 🙈
If you have something out right now that you're looking for feedback on, please let me know in the comments here, so I have that little notification in the corner bugging me until I get a chance to look at your app/project/thing.
I just put up version 1.0 of the landing page yesterday for https://bystander.io that I'd love feedback on.
I've been documenting every day's work on my blog, and I wrote a bit about the land page yesterday  and laid out my idea on the day one post 
But the gist of it is: I'm scratching my own itch here. Coming from a support engineering role, one thing that stuck out a ton is how many customers write in when presented with a user-facing error message (alerts, toasts, validations, etc) And understandably so, given that the error messages that we write for our own programs have varying degrees of usefulness.
Any how, I started to obsess over the cost of these errors:
Cost in support hours
Cost from users abandoning their tasks (your features!)
And began looking for ways to measure the cost this has by reducing lifetime customer value. This lead me down a manual audit of all the errors in our codebase at my old workplace, and cross referencing that to support tickets etc.
It was clear we could get some big wins by tracking the visual errors that we make, rather than just tracking client-side JS errors and server-side errors that fill up our logs. And using this new visual error tracking to A/B test error messages, to recover from their costs.
Whew, I cannot keep posts short 😅 Sorry about that, but thank you so much for having a look!