Two Presidents, One Chair

The board of Arista Networks took two actions on September 5, 2025, and the second one explains the first.

Action one: appoint Kenneth Duda, a co-founder and the company's chief technology officer, as President and Chief Technology Officer, effective immediately. Action two: amend and restate the bylaws so that the role of President may be held by more than one individual.

The bylaws had to be rewritten because Arista already had a president. Todd Nightingale had taken the title of President and Chief Operating Officer that June. And before either of them, for seventeen years without interruption, the president of Arista Networks was Jayshree Ullal, chairperson and chief executive officer.

She had held it since October 2008. After September 2025 she did not.

A chief executive shedding an operating title is the kind of governance detail that clears a proxy statement without comment. It is also, in a company with no announced succession plan, the most legible signal available about how the next one is being built - and it happened in the middle of the largest demand cycle the networking industry has ever seen.

She Left Cisco First

Ullal spent fifteen years at Cisco Systems, arriving in September 1993 by way of Crescendo Communications, where she was vice president of marketing when Cisco bought the company - its first acquisition. She left in May 2008 as senior vice president of the data center, switching and services group. Before Cisco: product and engineering roles at Ungermann-Bass, Advanced Micro Devices and Fairchild Semiconductor.

In October 2008 she became chief executive of Arista Networks and joined its board. The proposition was to sell data center switches against the company whose switching business she had just been running. Cisco has dominated the data center and campus networking markets historically, and still competes with Arista alongside Dell/EMC, Extreme Networks, Hewlett Packard Enterprise, Huawei, Juniper Networks, Nvidia and white-box vendors.

Seventeen years later the scoreboard is not ambiguous.

The Numbers She Posted

Arista closed fiscal 2025 with revenue of $9.006 billion, up 28.6 percent on the prior year, and GAAP net income of $3.511 billion, or $2.75 per diluted share. "2025 was the year of validation of our Arista 2.0 momentum, as we hit the milestone of shipping a cumulative of 150 million ports," Ullal said when the results ran. "We exceeded both our AI networking and campus expansion goals, delivering profitable growth and revenue of $9 billion."

The following two quarters were larger still. First quarter 2026 revenue of $2.709 billion, up 35.1 percent year over year. Then, on August 4, 2026, the number the company had been walking toward: "As we deliver our first $3 billion quarter in Q2 2026, it is clear that our Arista 2.0 platform strategy is compelling." Revenue of $3.036 billion, up 37.7 percent from the same quarter of 2025. GAAP operating margin of 45.4 percent, non-GAAP 49.9 percent. Diluted earnings per share of $0.95 GAAP, against $0.70 a year earlier.

Ullal's framing of what changed is architectural rather than cyclical. "Customers see networking as the central nervous system for infrastructure from the client to campus to data and AI centers." The pitch is convergence - one operating system from the laptop to the AI cluster - and in the first quarter of 2026 she put it as the ability "to deliver the mission-critical confluence of secure client-to-campus-to-cloud and AI networking."

Two Customers, Forty-Two Percent

There is a number in the annual report that does not appear in any earnings headline.

In fiscal 2025, two Arista customers each accounted for more than 10 percent of revenue. One represented 26 percent. The other represented 16 percent. Between them, 42 percent of a $9 billion business.

That is not new - two customers have exceeded the 10 percent threshold in each of the last three years - but the direction is the point. In 2023 the pair represented 21 percent and 18 percent: 39 percent combined. In 2024 they fell to 15 percent and 20 percent: 35 percent. In 2025 they climbed to 42 percent, the highest of the three years, driven almost entirely by one customer moving from 20 percent to 26 percent.

So the AI build-out that produced the first $3 billion quarter also produced the most concentrated revenue base Arista has carried in years. The company says so plainly in its own risk disclosure: large purchases by a relatively limited number of customers have accounted for a significant portion of revenue, and it has experienced unpredictability in the timing of their orders. Growth and dependence arrived on the same trucks.

The Title She Released

Against that backdrop, the September 2025 bylaw amendment reads less like housekeeping and more like insurance.

Ullal became chairperson of the board in December 2023, consolidating governance authority. Eighteen months later she began distributing operating authority in the other direction. Nightingale, who had run Cisco's enterprise networking and cloud business and then served as chief executive of Fastly, arrived as President and Chief Operating Officer in June 2025. Duda - one of the founders, at the company since 2004, chief technology officer since September 2011 and a director since December 2023 - was given President and Chief Technology Officer that September, with an expanded remit over cloud and AI systems engineering and business development.

An outside operator and an inside founder, each carrying half a presidency. Arista disclosed no agreements or arrangements entered into with Duda in connection with the appointment, and no arrangements or understandings with any other person behind it.

What the company has not done is name a successor, or say that it is looking for one. Ullal, 65, remains chairperson and chief executive, a director since 2008, and sits on the board of Snowflake, where she chairs the compensation committee.

The guidance for the third quarter of 2026 is approximately $3.3 billion in revenue and non-GAAP operating margin of 48 to 49 percent. Two customers still carry more than four dollars in every ten. Two presidents now report to a chief executive who spent seventeen years as her own.

The bylaws no longer say only one person can hold the job. That was the point.