Coolest project: I once worked for a customer who hosted an exhibition for a few thousand visitors in a big event arena in Stockholm.

They didn't want to use the existing ticket reading system on the arena so I had to build my own application compatible with barcode scanners (they said this about one week before the event).

It wasn't a complicated application to dev but with the tight deadline and no time to actually stress test it, it was the coolest thing to see hundreds of people streaming through the ticket station flawlessly.

Day 2 of the event I built a simple web application so I could see the flow rate of read tickets while I sat in the arena pub with a beer.