By this I mean what project should everyone build not because its useful or new, but because the process of building it forces you to learn something new. Some examples I've heard are your own programming language or a simple implementation of a database.
* Recursive file system management tools. Most developers cannot navigate a tree model and cower in great fear
* performance analysis/monitoring tools. Most developers are astoundingly bad at performance and then lie about it with weird unfounded guesses
* markdown to html parser or the opposite. Most developers have no idea the actual cost of involvement required for basic string parsing and wrongly believe it’s free
* network proxy. Aside from authentication this is mind blowingly simple. Most developers will supremely over engineer this
* API documentation. In a world where the average developer struggles to write an email actually describing inputs, purpose, and outputs clear enough for a stranger to follow can be quite the impossibility
I think writing a book about something technical. Either self-published (I like leanpub) or through a publisher. Doesn't have to be long, even a 30 page ebook is a big effort.
I have done this a few times and you learn so much and appreciate so much.
Other than that, I think it really depends on where you are starting. If you are a webdev, building an MVC framework. If you are a system programmer, building a basic HTTP.1/1 web server.
My process for any book I'm thinking about writing is:
- write out 10 titles for blog posts on the topic
- write 1-2 blog posts (this lets you see if you have interest/expertise)
- do a bit of research to see if someone else has written on the topic (some googling or reddit searching
- write the rest of the blog posts
If you can't write 10 blog posts about a topic, then you don't have either:
- the interest in the topic
- the knowledge in the topic
If no one else has written anything about the topic, it might not be worth writing about, but you also want to make sure your take is unique enough to be worth your effort.
Doing a programming language/compiler was very educational and did a lot to demystify computers for me.
I would also second the recommendations to write a game. If for no other reason than the fact that it is some of the most fun programming there is, you usually get to flex muscles you'd never get to in a boring web dev job.
Make that 6 iterations of such a site, one using wordpress, one using HTML and VIM and no tools, one using an SSG, one using k8s on 4 solar-powered rpis, one using a home-made CMS, and one written in Rust from scratch. Each one with a blog post "Why I...".
* performance analysis/monitoring tools. Most developers are astoundingly bad at performance and then lie about it with weird unfounded guesses
* markdown to html parser or the opposite. Most developers have no idea the actual cost of involvement required for basic string parsing and wrongly believe it’s free
* network proxy. Aside from authentication this is mind blowingly simple. Most developers will supremely over engineer this
* API documentation. In a world where the average developer struggles to write an email actually describing inputs, purpose, and outputs clear enough for a stranger to follow can be quite the impossibility