I'd be curious what topics people would find most interesting. The whole COVID lockdown has left me with an abundance of "free" time, and I work professionally in this space (on virtualization for Google Compute Engine). I've been feeling the need to write lately[0]. I know better than to try to tackle a whole textbook, but I'm hoping I could manage a series of blog posts.

[0]: My work has put me in a lot of meetings for quite some time. I've felt a decline in my written communication skills: it takes me a lot longer to write things than it used to, and I'm less happy with the results. Nothing to be done for it but to write!