Generally my way of figuring out what tech stack someone is using is to browse through their job offers. It's not a guarantee of course (I was hired as a rust developer at my old job only to be thrown into regurgitated spaghetti go). Anyhow, given that there's practically nothing related to native mobile development in the job offers (only one lists Java as a final mention), if I had to guess, my money would be a webvew app.
It's definitely is a webview app. The way it renders, it has to be webview.
Whatever the stack is they need to change it. Love Claude on web, but it's unusable on Android app. _Always_ hangs mid generation, image upload corrupts images, swallows chats at will
Recently, I decided to try out Claude for a month and bought the subscription right when mine for ChatGPT ended. However, after just a few days, I noticed how sluggish and inconvenient Claude feels on the web. Maybe it's partly because of my 4k screen, and it's not optimized for it, but I quickly switched back to ChatGPT due to the IMO better UX. Also, temporary chats are missing!
i also dislike my web experience with claude. it still generates completions after my free credits are consumed, and after it realizes there are no more free credits, the web app artificially removes the completions and throws an error. as a frontend dev, i'd think to check if there are credits left before even calling the api. i also dislike that there's a multiple second delay after hitting enter on claude. i'd expect to be on the chat page as soon as i hit enter.
BuiltWith says the web client is NextJS which is interesting as ChatGPT made a big switch away to Remix IIRC. https://builtwith.com/?https%3a%2f%2fclaude.ai%2fnew