A few years ago, I decided to migrate my personal website to a Common Lisp (CL) based static site generator that I wrote myself. In hindsight, it is one of the best decisions I have made for my website. It started out at around 850 lines of code and has gradually grown to roughly 1500 lines. It handles statically rendering blog posts, arbitrary pages, a guestbook, comment pages, tag listings, per tag RSS feeds, a consolidated RSS feed, directory listing pages and so on.
I have found it an absolute joy to maintain this piece of little 'machinery' for my website. The best part is that I understand every line of code in it. Every line of code, including all the HTML and CSS, is handcrafted. This gives me two benefits. It helps me maintain my sense of aesthetics in every byte that makes up the website. Further, adding a new feature or section to the site is usually quite quick.
I built the generator as a set of layered, reusable functions, so most new features amount to writing a tiny higher level function that calls the existing ones. For example, last month I wanted to add a 'backlinks' page listing other pages on the web that link to my posts and it took me only about 40 lines of new CL code and less than 15 minutes from wishing for it to publishing it.
Over the years this little hobby project has become quite stable and no longer needs much tinkering. It mostly stays out of the way and lets me focus on writing, which I think is what really matters.