How we created this year’s I/O save the date puzzle

Yesterday, we announced Google I/O 2023 will take place May 10 at Shoreline Amphitheatre in Mountain View in front of a live audience. And keeping with tradition, we did so by releasing a tricky Save the date puzzle designed for developers to solve.

“This year’s puzzle called for players to work asynchronously and use algorithmic thinking and matrix multiplication to solve a series of seven puzzles ranging in difficulty level,” says Kacey Fahey, who’s helping plan I/O this year. And now that they’ve been solved and we all know when I/O is, we can tell you a little about how they came together.

The riddles included two types of puzzles: color and binary-style. In the color puzzles, players interact with toggles, turning them on and off according to guidance from a clue. Each action may create a reaction, and when all colors are toggled on in the correct order, the puzzle is solved. In the binary-style puzzles, players use controls to shift columns and rows in the matrix in a specific order to reach the target end state, similar to a Rubik’s Cube. Each puzzle a player completed unlocked an animated badge, which could be shared on social media to show their progress.