I implemented traceroute for a networking class at one point and the most interesting part to me was how it worked. I had used traceroute and MTR for VPN debugging in the past, but had no clue how it could get all the routing nodes. Seeing that it just increased the TTL was shocking. I was overcomplicating it significantly in my head. After that, working with raw sockets was a nice exercise in general.
I wanted to share a very small traceroute implementation I wrote using Python. It is asynchronous and it supports probing over UDP or ICMP. It was a good networking exercise.