How can I get in contact with an Ubuntu developer to help with a problem?

You may get support through Ubuntu's official support but I am absolutely convinced that if you ask properly and be patient, you will get answers to your problems.

Your problem ( Wireless Internet Extremely slow on a TP-Link TL-WN821N ) isn't really an "ubuntu problem" but a hardware problem; your wifi card seems to be poorly supported as the wifi manufacturer does not release linux drivers for their card.

An ubuntu developer wouldn't be able to really help you.

In the future, I'd recommend buying hardware that's known to be fully supported in linux; e.g., buying a desktop from system76, zareason, thinkpenguin, or ovaha. Or certified hardware e.g., a linux supported wifi card Most drivers for wireless cards have to be written by someone for each specific chipset which takes some time (and maybe trial and error to figure out what the windows drivers are doing), so if its a relatively new card that no one's taken the time to get all the features working (e.g., 802.11n internet) it may not work perfectly. May I suggest just running a CAT5 ethernet cable in the meantime?

Some of the Ubuntu Developers also offer their help here in Askubuntu. Even if it takes a litte more time (Most of the time you will get an answer before the end of the day).

And not just Developers but also Ubuntu users in all levels of knowledge. From experts and beginners to Developers and programmers.