Last year I built a tool for visualizing log file volume (based on time) in your terminal [1]. Similar tools exist, but none were fast enough or easy to set up in a hurry, e.g. when you're investigating a production outage.

The year before that, a tool for visualizing ping latency as a heatmap [2]. My laptop's wifi had developed a severe latency stutter every ~500ms that was driving me nuts when using SSH and other interactive tools, not to mention killing my throughput. Once I could visualize it and saw the pattern, it was very clear that there was a system-level issue. Eventually traced it to a virtualization product's network driver.

It's definitely a pattern for me -- feel frustrated with diagnostic and data viz tools that are either too slow to handle or too complex to configure when I need them, and try to build simple tools that solve exactly the problems I keep bumping into. These smaller projects also provide good opportunities to practice with new languages or frameworks.

[1] https://github.com/acj/krapslog-rs (also krapslog-go)

[2] https://github.com/acj/pingrok