I've been working on a Rails + Vue project for 3 years. Plenty of experience of Rails (all of its years) but not much experience of SPA frameworks before then. The first year has been slow on the Vue side because I had to learn its weirdnesses (among the top 5: how you have to call dispatch("file/function") instead of calling that function right away and all the contort ways of passing data up and down between component trees). Then LLMs started to help and after three years I noticed that I could handle the code made alone. I would have probably reached this point in six months. On one side LLMs are crutches that slow down learning. On the other they made me deliver software faster, at least at the beginning.