Karim Z. Oussayef

Mr. Oussayef is a first-chair trial lawyer who litigates high-stakes patent infringement and technology disputes. Trained as a computer scientist with a focus on artificial intelligence, Mr. Oussayef combines deep technical fluency with courtroom skill to represent market leaders, such as Google and IBM, as well as early-stage companies at the forefront of new technologies. His practice spans pre-suit investigations, licensing disputes, trials, and appeals, with particular experience in AI and computer networking. Mr. Oussayef also serves on the Firm’s Executive Committee and leads its strategic efforts to evaluate and adopt AI, and to develop responsible and effective policies for those technologies.

Representative Matters
 

• Google - Complete Defense in $1.8+ Billion Dispute: As lead trial counsel, secured a complete defense victory in a four-day bench trial on inequitable conduct by proving that the plaintiff had abandoned the patent application for years and later deceived the Patent Office by forging a co-inventor’s signature on the revival petition.
   
• Fitbit - Summary Judgment and Federal Circuit Affirmance in $100+ Million Bluetooth Case: Won summary judgment of non-infringement after leading a multi-defendant joint defense through discovery, then led the appellate team to a unanimous affirmance by the Federal Circuit.
   
• Multinational Technology Company - Favorable Pretrial Rulings Leading to Settlement in $100+ Million Patent Case: Secured highly favorable rulings on key issues at the final pretrial conference, prompting a favorable settlement on the morning of trial.
   
• IBM - $82.5 Million Jury Verdict: Co-tried IBM’s first plaintiff-side patent trial in decades. Karim’s cross-examination of the opposing technical expert and key fact witnesses helped secure the verdict and contributed to his recognition as a Law360 Rising Star.
   
• Global Technology Company - Favorable Resolution in Financial Technology Jury Trial: As lead trial counsel, persuaded the jury to reject willful infringement allegations, limiting damages to a small fraction of the initial demand and paving the way for a favorable settlement.
   
• Appellate Victories: Several victories before the Federal Circuit; convinced a panel of judges to unanimously overturn the Patent Trial and Appeal Board on two independent inter partes review decisions.

Mr. Oussayef earned his J.D. from Boston University and his B.S. in Computer Science, with a focus on artificial intelligence, from the University of Rochester. Before joining Desmarais LLP, he was an associate in the Intellectual Property Group at Ropes & Gray LLP.

Courts

• United States District Court for the Eastern District of New York
• United States District Court for the Southern District of New York
• United States Court of Appeals for the Federal Circuit

Other Distinctions

• Best Lawyers - Individual Recognition for Patent Law (2021-2025)
• IAM 1000 - Individual Recognition for Litigation

Memberships & Affiliations

• Massachusetts State Bar
• New York State Bar