Josh Weisenfeld is an associate in the Intellectual Property Group in the firm’s San Diego (Del Mar) office.
Josh advises and represents clients across the full lifecycle of intellectual property—helping them build, strengthen, and enforce patent portfolios, and defending against allegations of patent infringement. His practice combines high-volume, strategic patent preparation and prosecution with complex patent litigation, including matters in federal district court and investigations before the U.S. International Trade Commission (ITC).
Patent Preparation, Prosecution, & Portfolio Development
Josh works closely with in-house teams, engineers, and inventors to develop patent strategies aligned with business objectives and product roadmaps. He drafts and prosecutes patent applications in a range of technologies, with a particular focus on:
- Networking, computing, and computer infrastructure
- AI-enabled systems and software-related technologies
- Electronics and electromechanical systems
- Aerospace and defense technologies
- Automotive systems
- Biomedical devices and related instrumentation
- Oil and gas, energy, and industrial systems
- Consumer products and devices
- Recreation products and systems
Patent Litigation
Josh maintains an active patent litigation practice focused on large-scale, commercially significant disputes. He regularly develops and advances non-infringement and invalidity positions, including through technical analysis of accused products and asserted patent claims, and has significant experience with post-grant proceedings such as inter partes review (IPR) and ex parte reexamination (EPR). He supports clients in defending against infringement allegations and in pursuing strategic offensive and defensive outcomes in matters that require technical depth, coordinated strategy, and a detailed understanding of complex products and markets.
Technical Background
Josh’s technical experience spans a broad range of disciplines, including electronics and instrumentation, electrical engineering, nuclear engineering, robotics, electromagnetics, optics, mechanics and mechanical engineering, astronomy and astrophysics, and experimental modern physics. He leverages this background to translate complex technical concepts into clear advocacy in both prosecution and litigation contexts.
Prior Experience, Leadership, & Writing
While in law school, Josh served as a Student Attorney in the Cardozo Tech Start-Up Clinic, providing pro bono counsel to early-stage technology companies on formation, governance, privacy, patents, trademarks, and blockchain-related matters. He was a Staff Editor for the Cardozo Journal of Equal Rights and Social Justice, where he published Medical Marijuana Patients: Discrimination & the Search for Employment Protections, analyzing the intersection of evolving medical marijuana laws and employment protections under the Americans with Disabilities Act. He also served as Vice President of the Benjamin N. Cardozo Intellectual Property Law Society, Treasurer of the Cardozo Start-Up Society, and a Programming Committee Member of the Cardozo Data Law Initiative, and competed in the CUBE Innovators Invitational, where he co-founded a legal tech company. Josh also regularly publishes articles and blog posts on emerging and developing issues in patent law, including AI and its integration into legal practice, and was recognized by the JD Supra Readers’ Choice Awards in 2025 for a Top Read Article.