We have a super diverse userbase, so this is a fun question! Some pointers:

Development:

- Debug your own apps/devices (which do not come with Chrome Devtools).

- Simple Python scripts to replace/inject website content. (https://docs.mitmproxy.org/stable/addons-overview/)

- Capture a web page/API and then replay the responses offline. (https://docs.mitmproxy.org/stable/overview-features/#server-...).

- Replay requests for testing. (https://docs.mitmproxy.org/stable/overview-features/#client-...)

Privacy:

- Figure out what your Covid app is sending out (https://seancoates.com/blogs/how-i-helped-fix-canadas-covid-...)

- Look at how evil IoT devices for pets are (https://www.nytimes.com/2018/12/11/realestate/spying-on-the-...)

- Generally find more evil stuff (https://mitmproxy.org/publications/)

Security:

- Reverse-engineering custom binary protocols is never fun, but with mitmproxy you can at least write custom contentviews to dissect stuff. (https://github.com/mitmproxy/mitmproxy/blob/main/examples/ad...)

- Fiddle with generic TLS-protected TCP streams. (https://github.com/mitmproxy/mitmproxy/blob/main/examples/ad...)

- Dump TLS master secrets for WireShark. (https://docs.mitmproxy.org/stable/howto-wireshark-tls/)