Honestly speaking, I know there's a lot, we developers and engineers can do but I have never imagined myself putting up a somewhat complete solutions in less than 24 hours.
Last December, I joined the RE:Hack - Smart Living 24 hour Hackathon, an event organized by TM with my 2 other colleagues. All these years in the industry, I was apathy towards development beyond my job roles or anything that brings no ROI to the company I worked for but since hackathon is widely talked about in M2, I went ahead and joined the crowd.