Douglas E. Lumish

With nearly 30 years of experience, Doug has an exceptional track record of securing favorable outcomes for clients at all stages of litigation, including jury trials, bench trials, and on appeal. His diverse practice encompasses patent, trade secret, contract, licensing, fraud, and other technology and life sciences related cases. Doug litigates before all of the principal IP venues, including in state and federal trial and appellate courts, and before the International Trade Commission and customs regulators. He regularly advises clients in significant trade secrets and multi-patent infringement actions, winning jury trials and summary judgments for plaintiffs and defendants alike, and defeating billions of dollars in claims against his clients.

Notable Experience*

Doug has advised numerous Fortune 500 technology and life sciences companies across industries during his career, including Abbvie, Amazon, Applied Biosystems, Apple, Arista Networks, Codexis, Comcast, Disney, Google, Hitachi, Hyundai, L.G., Life Technologies, Meta, Microsoft, Oracle, Orca Security, Peloton, Skype, Symantec/GenDigital, ThermoFisher, Western Digital, WhatsApp, Yahoo!, and Zoom, among others.

Some of his major engagements include representing:

• Amazon in patent and trade secret cases in various jurisdictions. Doug was lead trial counsel in Amazon’s summary judgment win over Telebuyer in the Western District of Washington.
• Google in patent cases in Texas, Delaware, and other courts. Doug was lead trial counsel in the Eastern District of Texas for Google and YouTube in its patent dispute with the University of California and Eolas over patents alleged to cover all modern, interactive web pages. Achieved a jury verdict of patent invalidity and defeated claims for hundreds of millions in damages.
• Meta in patent and trade secret cases throughout the country. Doug was lead trial counsel in Meta’s summary judgment win over MasterObjects in the Northern District of California, and for WhatsApp in its summary judgment victory against TriPlay.
• Arista Networks in patent and trade secret cases including, among others, several ITC and Customs actions brought by Cisco Systems. Doug was lead trial counsel in Arista’s trial wins in the ITC against Cisco and in a licensing dispute against OptumSoft.
• Disney in a number of patent matters. Doug was lead trial counsel in Disney’s summary judgment win over theme park ride designer, Raven Sun.
• Orca Security in its patent action against competitor, Wiz, in the District of Delaware concerning cloud security technology.
• Zoom in its contract dispute with RingCentral. Doug was lead counsel in defeating RingCentral’s requests for an injunction, and lead appellate counsel in securing that win with an affirmance by the Ninth Circuit.
• Comcast in patent disputes with Rovi. Doug was lead trial counsel in Comcast’s complete win over Rovi in an ITC trial concerning various communications and set top box technologies. Also won a inter partes Customs proceeding and obtained a finding of non-infringement and approval of a redesign to Comcast’s system.
• Codexis, a California-based biotech company, in a patent infringement action against rival EnzymeWorks. Obtained final judgment that EnzymeWorks infringed all 10 Codexis patents-in-suit.
• Peloton in its patent action against MadDogg. Doug was lead trial counsel in this action in the Eastern District of Texas which ended with summary judgment invalidating MadDogg’s patents.
• Symantec in a multi-patent jury trial. Obtained a jury verdict of non-infringement on the key patent at trial (eliminating 96% of the damages risk to the client), and invalidated the remaining two patents on post-trial motions and on appeal.
• Western Digital and Hitachi Global Storage Technologies in numerous patent matters. Doug was lead trial counsel in HGST’s jury trial in the Eastern District of Texas which ultimately concluded with JMOL of no infringement.
• Velodyne in several competitor lawsuits concerning infringement of Velodyne’s foundational patents on rotating LiDAR technologies. After defeating multiple IPRs and prevailing in district court proceedings, obtained highly favorable licenses to Velodyne’s patents.
• ThermoFisher in a multi-patent infringement action brought by Becton Dickinson which sought to shut down a ThermoFisher business manufacturing unit. Defeated a preliminary injunction motion, then obtained summary judgment of non-infringement of Becton Dickinson’s lead patent.
• TransPerfect Global, Inc., in a multi-patent infringement case related to website translation technologies. Won a jury verdict finding three patents owned by defendant to be both invalid and not infringed. Jury awarded TransPerfect damages in a victory The Daily Journal named a Top Plaintiffs’ Verdict of the year.
• Microsoft, obtaining a complete defense jury verdict against Acacia in the Eastern District of Texas, which had sought hundreds of millions of dollars in damages.

*Includes matters handled prior to joining Weil 

Doug is consistently recognized by industry publications as a preeminent leader in the IP field. He is currently ranked by Chambers USA in Band 1 in California for Intellectual Property: Patent Litigation, where clients in the most recent edition praised him as “one of the best trial attorneys in the field.” Doug is also highly ranked nationally by both Chambers USA and Chambers Global for Intellectual Property and Trade Secrets, with the publication calling him a “respected litigator active across trade secrets misappropriation patent and trademark disputes, regularly appearing in the Federal Circuit and the ITC.” He’s been named a “Litigator of the Week” by The American Lawyer and has twice received national recognition by Law360 as an MVP, in the Technology and IP categories. The Daily Journal has long named Doug to its distinctive “Top Intellectual Property Lawyers” (2011-2025) and “Top Trade Secrets Lawyers” (2019-2024) lists, while Lawdragon has honored him as a “Leading Global IP Lawyer” (2025) and “Leading Litigator in America” (2023-2025). Benchmark Litigation ranks Doug as a National Litigation Practice Area Star and Local Litigation Star for IP Litigation (2020-present), while Legal 500 has named him one of four “Hall of Fame” lawyers for Intellectual Property: Patents: Litigation (Full Coverage) and one of 11 “Hall of Fame” lawyers for Trade Secrets (Litigation and Non-Contentious Matters). Doug is also recommended by IAM Patent 1000, where clients have remarked that he “brings a stellar track record track record in securing wins across all technical disciplines.” He is a Fellow of the Litigation Counsel of America.

Doug spent the first 15 years of his career in Weil’s Patent Litigation practice, where he helped win important victories for Hitachi, Microsoft, Yahoo!, Oracle, and many other clients. He went on to serve in multiple leadership positions at another major global law firm, including Global Vice Chair of its Litigation and Trial Department, Global Co-Chair of its IP Litigation practice, and Co-Chair of the firm’s Bay Area Litigation and Trial Department. Prior to law school, Doug gained in-depth technical experience as a systems consultant to technology companies.