Advent of Code is an annual set of Christmas-themed computer programming challenges that follow an Advent calendar. It has been running since 2015.
The programming puzzles cover a variety of skill sets and skill levels and can be solved using any programming language. Participants also compete based on speed on both global and private leaderboards.
The event was founded and is maintained by software engineer Eric Wastl.
Puzzles consist of two parts that must be solved in order, with the second part not revealed to the user until the first part is solved correctly. Participants are awarded a silver star for completing the first part of a daily puzzle, and a gold star after completing the second.
Each puzzle contains a fictional backstory that is the same for all participants, but each person receives a different piece of input data and should generate a different correct result.
Puzzles are released on a daily schedule from December 1 to December 25 at midnight EST. There is no time limit to complete the puzzles, and puzzles from past years' events remain available to solve.