I built a tool to search all of Shakespeare's works as a resource for my partner at the time and her colleagues who were studying classical acting. They found that they struggled to pull together lists of where different terms and concepts were used in Shakespeare. I was familiar with the MIT Shakespeare Library that has been around since nearly the dawn of the web, so I used Svelte to pull it in client side and perform crude exact-match searching over the whole library.
The site ends up loading a lot of text into your webpage, but it worked for the narrow use case it was built for. I had a lot of fun figuring out how to generate links to the exact line and highlight search matches, thankfully the Shakespeare Library is very well-structured HTML compared to most websites.