A company party usually at a start up that celebrates nothing in particular. It is neither tied to a holiday nor to a milestone of the company. Dot proms are either held in the office after-hours complete with cheap decorations (like the gymnasium for a public school prom) or a ballroom is rented out and there is a more elaborate theme (like a private school prom). Example: We had stayed late every night at the office this week so we didn't want to stay late again for another lame dot prom.
DOT PROM
Meaning of DOT PROM in English
Slang English vocab. Английский сленговый словарь. 2012