Alex Williams is a senior partner at Pearson Specter Litt and one of Harvey Specter's trustworthy friends. After working for many years at Bratton Gould with no opportunities for career advancement, Harvey offered him partnership if he came to PSL and brought his biggest client with him, which he agreed to do.
Apart from being friends, Harvey wanted to onboard Pfizer as a client of Pearson Specter Litt in order to displace Jim Reynolds, who was Jessica Pearson's older client. Alex demanded that he be made a name partner in order to make the switch, which Harvey momentarily agrees, but Louis and Donna do not agree with Harvey. Finally, Harvey and Alex agree to terms.
His move to Pearson Specter Litt angered his former firm and lawsuits against clients of Pearson Specter Litt by Bratton Gould start pouring.