Feel free to tell about what your day looks like. I'm exploring different positions so it'd be very valuable to me. I've already done a few courses in C# and Python, they seem to be quite common. My goal here is to get to know this role better, for now I have limited information about it. Is it rather repetitive, or is there always something new to do? What part of it do you enjoy the most and the least? Is it true that many desktop apps are really webapps?
Most of my back-end work is web APIs and DTL systems. Fetch data from somewhere (another web service, a database, text files) and do something with it (assemble several bits to send to a web page, transform and/or validate it and stuff it into a database table, send it to a report server to generate a document, etc.).
The worst part is probably that a lot of the apps we maintain in my organization are quite old, so it isn't unusual for me to have to work with 15 year-old Visual Basic apps. That kinda sucks because I don't like working in old VB code, and it's rare for there to be any budget for updating them.
A big part of the job is just knowing the domain and what the various apps are doing so that when something is wrong or someone needs to know something it doesn't take too long to fix the problem or answer the question.
Mostly it's fun writing code. The not-fun parts are mostly unrelated to the type of project (getting people who want something to figure out what they want or to understand that what they want is not possible, etc.)
Our desktop apps are mostly either old C# winforms or WPF apps. I'm kind of avoiding new C# desktop apps until Microsoft gets their shit together. The bulk of our new development has shifted to the web instead of desktop. Plus we have occasional mobile apps (curiously, mobile tends to be the opposite of desktop, everybody wants an app installed on their device instead of a website, where on desktop everybody wants stuff in a browser).