Cadence Design Systems, Inc. is an American multinational electronic design automation (EDA) software and engineering services company, founded in 1988 by the merger of SDA Systems and ECAD, Inc. The company produces software, hardware and silicon structures for designing integrated circuits, systems on chips (SoCs) and printed circuit boards.

Cadence Design Systems, headquartered in San Jose, California, in the North San Jose Innovation District, is a supplier of electronic design technologies and engineering services in the electronic design automation (EDA) industry. The company develops software used to design chips and printed circuit boards, as well as intellectual properties (IP) covering a broad range of areas, including interfaces, memory, analog, SoC peripherals, dataplane processing units, and verification.

Cadence products primarily target SoC design engineers, and are used to move a design into packaged silicon, with products for custom and analog design, digital design, mixed-signal design, verification, and package/PCB design, as well as a broad selection of IP, and also hardware for emulation and FPGA prototyping.

To help integrate, verify, and implement complex digital SoCs, there are solutions that encompass design IP, timing analysis and signoff, services, and tools and methodologies. The company also provides products that assist with the development of complete hardware and software platforms that support end applications.

Cadence Design Systems was the result of a merger perfected in 1988 of Solomon Design Automation (SDA), co-founded in 1983 by Richard Newton, Alberto Sangiovanni-Vincentelli and James Solomon, and ECAD, co-founded by Glen Antle and Paul Huang in 1982. Joseph Costello was appointed as CEO from 1988–1997, and Cadence became the largest EDA company during his tenure.

Following Costello as CEO were Jack Harding (from 1997-99), Ray Bingham (from 1999-2005), and Mike Fister (from 2005-2008).

Following the resignation of Fister, the board appointed Lip-Bu Tan as acting CEO. In January 2009, the company confirmed Lip-Bu Tan as President and CEO. Tan had been most recently CEO of Walden International, a venture capital firm, and remains chairman of the firm. He has served on the Cadence Board of Directors since 2004, where he served on the Technology Committee for four years.

In 2013, Cadence celebrated its 25th anniversary. In 2015 it was named one of the top 100 places to work by Fortune magazine.

At the end of 2016, the company employed more than 7,100 people and reported 2016 revenues of approximately $1.82 billion. In November 2007 Cadence was named one of the "50 Best Places to Work in Silicon Valley" by San Jose Magazine.

According to Glassdoor, it is the fifth highest-paying company for employees in the United States as of April 2017.

Cadence's product offerings are targeted at various types of design and verification tasks which include:

In addition to EDA software, Cadence provides contracted methodology and design services as well as silicon design IP, and has a program aimed at making it easier for other EDA software to interoperate with the company's tools.

Cadence was involved in a 6-year-long legal dispute with Avanti Corporation, in which Cadence claimed Avanti stole Cadence code, and Avanti denied it. According to Business Week "The Avanti case is probably the most dramatic tale of white-collar crime in the history of Silicon Valley". The Avanti executives eventually pleaded no contest and Cadence received several hundred million dollars in restitution. Avanti was then purchased by Synopsys, which paid $265 million more to settle the remaining claims. The case resulted in a number of legal precedents.

The Cadence group Quickturn was also involved in a series of legal events with Mentor Graphics/Aptix. Mentor purchased rights to an Aptix patent, then sued Cadence. In this case, the CEO of Aptix, Amr Mohsen, forged a notebook in order to make the patent case stronger. When suspicions were raised, he staged a break-in of his own car to get rid of the evidence, resulting in charges of obstruction of justice. Trying to avoid this, he attempted to flee the country, only to be caught with an illegal passport and a pile of cash. While in jail for this offense, he was recorded offering money to intimidate witnesses and kill the judge. In order to fight the new charges, he tried to feign psychological problems, but left a trail of evidence of his research into this defense, and how it might be done. He was charged with attempting to delay a federal trial by feigning incompetency, but was convicted anyway. According to the lawyers concerned, the original notebooks were not needed for the trial. The patent filing date, which was not in dispute, would have sufficed.

The company has also acquired Valid Logic Systems, High Level Design (HLD), UniCAD, CadMOS, Ambit Design Systems, Simplex, Silicon Perspective, Plato and Get2Chip.

Denali Software, Inc. was an American software company, based in Sunnyvale, California, now acquired by Cadence. The company produces electronic design automation (EDA) software, intellectual property (IP) and design cores and platforms for memory, other standard interfaces and system-on-chip (SoC) design and verification. It has its engineering offices in Sunnyvale, Austin and Bangalore. Incorporated in 1996, Denali is headquartered in Sunnyvale, California and serves the global electronics industry with direct sales and support offices in North America, Europe, Japan and Asia.

On May 2010, Cadence Design Systems announced that it would acquire Denali for $315 million.

Valid Logic Systems was one of the first commercial electronic design automation (EDA) companies, now acquired by Cadence. It was founded in the early 1980s, along with Daisy Systems Corporation and Mentor Graphics, collectively known as DMV. The engineering founders were L. Curtis Widdoes, Tom McWilliams and Jeff Rubin, all of whom had worked on the S-1 supercomputer project at Livermore Labs.

Valid acquired several companies such as Telesis (PCB layout), Analog Design Tools, and Calma (IC layout). In turn, Valid was acquired by Cadence Design Systems in the early 90s.

Valid built both hardware and software, for schematic capture, logic simulation, static timing analysis, and packaging. Much of the initial software base derived from SCALD ("Structured Computer-Aided Logic Design"), a set of tools developed to support the design of the S-1 supercomputer at Lawrence Livermore National Laboratory. Later, Valid expanded into IC design tools and into printed circuit board layout.

At first, Valid ran schematic capture on a proprietary UNIX workstation, the SCALDSystem, with static timing analysis, simulation, and packaging running on a VAX or IBM-compatible mainframe. However, by the mid-1980s, general purpose workstations were powerful enough, significantly cheaper. Companies such as Mentor Graphics and Cadence Design Systems sold software only for such workstations. By 1990, almost all Valid software was also running on workstations, primarily those from Sun Microsystems.