Definition of "algo"

Together, the Masons craft a new algorithm to make an end-run around Axe’s sabotage — or so they want him to believe. With the help of a surveillance photo procured by his dirty-deeds specialist Hall (Terry Kinney), Axe has a copy of the algo he spends a full day attempting to decipher before realizing it has a mistake.

2019 March 31, Sean T. Collins, “‘Billions’ Season 4, Episode 3: Hurts So Good”, in The New York Times‎