GENDER DISCRIMINATION! -_-
If you are a GIRL, there's a HIGH chance for you to win the Hackathon. If you are a BOY, well... :|

The worst part of hackathons are schedules which leaves no time for actual coding!
I was once at 2 day event. Day 1 contained an intro lecture, 'getting to know your team' exercise, idea generation phase, idea feedback from industry people, mandatory coffee breaks, and a little bit of coding at the end.
Day 2 consisted of 'adding thet final touches to your hack', a random lecture from the company hosting the event, info from the judges on how to pitch, a trial run of the pitch and then the final pitches...
I barely think we got to code for 3 hours.

When they're clearly used as a way to get free overtime rather than develop an idea for fun.

Is anyone ever "hacking" anything at a hackathon these days?

Seems more like "building 40% of a CRUD app really fast!"

(but maybe I'm seeing the wrong hackathons)

Why ask me? Never been to one.

Gundam

That I haven’t been to one

That they exist, and that employers use them for "team building".

Hackathon sponsored by Microsoft and there you are with your dumb team implementing features with Amazon Web service...
I wish you good luck. 👍

The fact that there is such a thing...

Most probably the short time pressure and the mindset of "in these x hours/days, I can't do/think/be interested in anything else but the hackathon". It feels like it significantly disrupts my daily flow

When your teammates suck. You did your part of the code and the 1 single thing you left for your teammate is trash.

When they steal your idea, oh wait

The titles - some of these events have the most insufferable titles. If it's not some cringey pop-culture acronym like AVNGRS then it's a super nondescript, mysterious title like "The Bakeoff", which helps nobody and doesnt do the event justice.

I would much prefer "MIT Anual CTF, 2021" than the usual bullshit fanfare referencing the Matrix.

The hackathons I have been in have been great. The one negative experience was some guy that showed up, didn't code, and kept asking people who were clearly busy about writing some stock trading code. It is like he could not wait until the end of the event (2 hours).

Mid hackathon reviews.
It kills the excitement that a judge might have seeing the thing for the first time in the final review.
Instead the final review becomes - "Hey, what did you improve from the last time?"

**Its not a fucking sprint**

Never actually done one. Hopefully that can change this year

The most positive things about hackathons I can think of are the facts that they're are rarely mandatory and doesn't matter much to anyone other than the organisers or "winner" ...
On occasion swag or catering (if there's a bar) can kinda make up for it :)

Stupid, useless members that do nothing and just eat free Individuales and Sin Culpa. Wait-