Jan Koum

Jan Koum
Koum in 2014
Jan Koum
Born	24 2, 1976
Birthplace	Kyiv, Ukrainian SSR, Soviet Union
Nationality	American
Occupation	Businessman, computer programmer
Known for	Co-founding WhatsApp
Education	San Jose State University (did not complete)

Jan Borysovych Koum (Template:Lang-uk; born February 24, 1976) is an American billionaire businessman and computer programmer who co-founded WhatsApp, one of the world's most widely used mobile messaging applications. Born in Soviet-era Kyiv, Ukraine, Koum immigrated to the United States as a teenager with his mother and grandmother, settling in Mountain View, California, where his family relied on food stamps and government assistance to survive. He taught himself computer networking from manuals purchased at a used bookstore and eventually secured work at Yahoo!, where he met his future WhatsApp co-founder Brian Acton. Together, the two created WhatsApp in 2009, building it into a global messaging platform that attracted hundreds of millions of users with its simple, ad-free design and commitment to user privacy. In February 2014, Facebook (now Meta Platforms) acquired WhatsApp for approximately US$19.3 billion, one of the largest technology acquisitions in history. Koum served as CEO of WhatsApp and as a member of Facebook's board of directors until 2018, when he departed amid reported disagreements over the company's data privacy practices. His personal story — from a childhood marked by scarcity in a crumbling Soviet state to the helm of a multibillion-dollar technology company — has been widely cited as one of the most notable immigrant success stories in Silicon Valley history.

Early Life

Jan Koum was born on February 24, 1976, in Kyiv, in what was then the Ukrainian Soviet Socialist Republic of the Soviet Union. He grew up in a small village outside the capital, in a home that lacked hot water; his family's telephone conversations were at risk of being monitored by the Soviet state, an experience that would later profoundly shape his commitment to encrypted, private communications.

Koum's family was Jewish, and they lived in an environment marked by anti-Semitic sentiment and political repression. When Koum was sixteen years old, in 1992, he immigrated to the United States with his mother and grandmother, settling in Mountain View, California. His father remained in Ukraine and never joined the family in America; he died in 1997. The family lived in a small two-bedroom apartment provided through government-subsidized housing, and they relied on food stamps to meet their basic needs. His mother took work as a babysitter, though she was later diagnosed with cancer.

Despite these difficult circumstances, the young Koum developed an early fascination with computer technology. He purchased manuals on computer networking from a used bookstore and taught himself how computer systems communicated with one another, returning the manuals for a refund after reading them. By the age of eighteen, Koum had developed sufficient skill to attract the attention of a group of hackers on the internet, and he began exploring the architecture of computer networks in earnest.

Koum's mother died in 2000. In interviews, Koum has spoken about the lasting impact of growing up under the Soviet system, where government surveillance of communications was routine. This background directly influenced his philosophy that messaging should be private and free of advertising or data harvesting, principles that would define WhatsApp's product design.

Education

Koum enrolled at San Jose State University, where he studied mathematics and computer science. During his time as a student, he also began working at Ernst & Young as a security tester, a position that introduced him to the professional technology world. Through his work in the security field, Koum came to the attention of Yahoo!, and he joined the company as an infrastructure engineer. He ultimately did not complete his degree at San Jose State University, leaving the program to focus on his career in the technology industry.

Career

Yahoo!

Koum joined Yahoo! in 1997, where he worked as an infrastructure engineer. It was at Yahoo! that he met Brian Acton, a fellow engineer who would become his longtime friend and eventual business partner. The two worked together at the company for approximately nine years. Koum's work at Yahoo! gave him deep experience with large-scale internet systems and network architecture. Both Koum and Acton eventually grew dissatisfied with the direction of the company, and they left Yahoo! together in September 2007.

After leaving Yahoo!, Koum and Acton took time off to travel and decompress. They both applied for engineering positions at Facebook, but both were rejected. Acton later tweeted about his Facebook rejection, a detail that would become an ironic footnote when Facebook later acquired WhatsApp for billions of dollars.

Founding WhatsApp

In January 2009, Koum purchased an iPhone and recognized the potential of the nascent App Store ecosystem. He conceived of a simple application that would allow users to set statuses next to their names — essentially an internet-connected address book that showed what people were doing at any given moment. He incorporated WhatsApp Inc. on February 24, 2009 — his birthday — in California.

Koum discussed his idea with Acton, who encouraged him to pursue it. Koum recruited a developer, Igor Solomennikov, a friend in Russia, to help build the early version of the app. The initial product was buggy and frequently crashed, and Koum nearly abandoned the project. However, after Apple introduced push notifications in June 2009, WhatsApp's utility changed dramatically. Users began sending pings and informal messages to each other through the status update feature, effectively converting WhatsApp from a status-display app into an instant messaging platform.

This pivotal shift convinced Koum to rebuild WhatsApp as a full messaging service. Acton, who was still looking for full-time work, began helping with the project and contributed $250,000 in seed funding in October 2009, becoming a co-founder. The app charged a modest annual fee of $0.99, deliberately avoiding the advertising-supported business model that dominated the technology industry. Koum had a strong aversion to advertising, a stance he attributed to the intrusive marketing culture he had observed during his years at Yahoo! and his broader distrust of data collection rooted in his Soviet upbringing.

WhatsApp grew rapidly, particularly in international markets where SMS fees were high. The application's simplicity, reliability, and cross-platform compatibility made it an appealing alternative to traditional text messaging. In the early years, WhatsApp operated with a notably lean team — Koum ran the company with a handful of engineers and no marketing or public relations staff. Koum resisted the Silicon Valley convention of growing a company through aggressive hiring and venture capital spending, preferring to keep WhatsApp small and profitable.

Koum was known for his reluctance to identify with the Silicon Valley "entrepreneur" label. In interviews, he expressed discomfort with the term, noting that he simply wanted to build a useful product rather than conform to the startup culture of the San Francisco Bay Area. WhatsApp's growth was powered largely by word of mouth and user satisfaction rather than by marketing campaigns or media engagement.

Facebook Acquisition

On February 19, 2014, Facebook announced it had reached an agreement to acquire WhatsApp for approximately US$19.3 billion — $4 billion in cash, approximately $12 billion in Facebook shares, and an additional $3 billion in restricted stock units to be granted to WhatsApp's founders and employees over four years. The deal was one of the largest technology acquisitions in history at the time. For Koum, who had been rejected for a job at Facebook just five years earlier, the acquisition represented a remarkable reversal of fortune.

The acquisition made Koum a billionaire. He signed the deal papers at the door of the North County Social Services office in Mountain View, California — the same building where he and his mother had once stood in line to collect food stamps after immigrating from Ukraine. Koum later described this as an intentional symbolic gesture.

As part of the acquisition agreement, Koum joined Facebook's board of directors and continued to serve as CEO of WhatsApp, operating the messaging service as a semi-independent unit within the larger company. At the time of the acquisition, WhatsApp had approximately 450 million monthly active users and was adding roughly one million new users per day.

Departure from Facebook

In April 2018, reports emerged that Koum planned to leave Facebook following prolonged disagreements with the parent company over WhatsApp's direction. According to The Washington Post, the clashes centered on Facebook's efforts to use WhatsApp's personal data for advertising purposes and to weaken the app's encryption — changes that conflicted with Koum's founding principles of privacy and an ad-free user experience.

Koum confirmed his departure from both the CEO role and Facebook's board of directors in early May 2018. His exit followed that of co-founder Brian Acton, who had left Facebook in September 2017 and later publicly urged people to delete their Facebook accounts.

Despite leaving his operational role, Koum continued to show up at Facebook headquarters after his departure in order to vest approximately $450 million in unvested stock that was part of his acquisition compensation package — a practice sometimes referred to in Silicon Valley as "rest and vest."

Personal Life

Koum is a Jewish immigrant from Ukraine. He has spoken publicly about the influence of his upbringing in the Soviet Union on his values, particularly his commitment to personal privacy and his distrust of government and corporate surveillance of communications.

In 2014, Bloomberg News reported that Koum had been issued a restraining order related to a past personal matter. Koum publicly apologized for the incident, which he described as a period he was not proud of.

Koum has been known to maintain a low public profile, rarely granting interviews or making public appearances. He has expressed a general distaste for the media attention and celebrity culture associated with Silicon Valley wealth.

In more recent years, Koum has been reported to own multiple superyachts. His 328-foot yacht Moonrise was listed for sale at a reported price of approximately $380 million, reportedly because Koum had commissioned a successor vessel with specifications more to his liking, including greater speed and quieter operation. In 2025, Koum and interior designer Rémi Tessier reached a settlement in a legal dispute related to the design of two superyachts and a luxury property.

Recognition

Koum has been consistently listed among the wealthiest individuals in the world by Forbes. In 2023, Forbes ranked him 44th on its list of the richest Americans.

In 2025, The Jerusalem Post included Koum in its ranking of influential Jewish billionaires, noting his impact on Jewish life and Israel through investment and influence.

Koum's story has been cited in numerous media profiles as an emblematic Silicon Valley immigrant narrative — a trajectory from food stamps and government-subsidized housing to the creation of a product used by billions. His journey from a small village outside Kyiv to the Facebook boardroom was a frequent subject of coverage during the 2014 acquisition.

Philanthropy

Koum has made notable political and philanthropic contributions. He donated a reported $2 million to the American Israel Public Affairs Committee (AIPAC), described at the time as a record individual contribution to the organization's campaign efforts.

Through the Koum Family Foundation, Koum has made significant philanthropic investments in academic and scientific institutions, particularly in Israel. In 2024, the Jan Koum Center for Nanoscience and Nanotechnology was completed at Tel Aviv University, designed by the architectural firm Michel Rémon & Associés. The facility is the largest university-based center of its kind in Israel.

In November 2025, the Koum Family Foundation endowed the Jan Koum Israel Studies Program at Stanford University's Freeman Spogli Institute for International Studies, establishing a permanent academic program focused on Israel studies. The endowment built on a successful pilot program and was intended to deepen scholarship and teaching on Israel at the university. The gift was notable in the context of broader discussions about Jewish philanthropic engagement with American universities; reporting in eJewishPhilanthropy noted that Koum was "doubling down" on academia at a time when some Jewish donors were reconsidering their support for higher education institutions.

Legacy

Jan Koum's career is most closely associated with the creation of WhatsApp, which grew from a two-person project in 2009 to one of the most-used communication platforms on earth, reaching over a billion users within several years of its founding. The application's design philosophy — simplicity, reliability, minimal data collection, no advertising, and strong encryption — reflected Koum's personal convictions, particularly his childhood experience under a surveillance state.

The US$19.3 billion acquisition by Facebook in 2014 remains one of the largest technology deals in history and reshaped expectations about the valuation of messaging platforms. Koum's subsequent departure from Facebook in 2018 over disagreements about privacy and data monetization became a widely discussed case study in the tensions that can arise when founders sell their companies to larger corporations with different business models.

Koum's life story — from a Soviet childhood marked by poverty and surveillance, through immigration and dependence on government assistance, to the founding of a global technology company — has been extensively profiled as one of the most dramatic rags-to-riches narratives in the history of American technology. His insistence on building a company without advertising revenue, and his willingness to walk away from Facebook when he believed his principles were being compromised, distinguished him from many of his peers in Silicon Valley.