Slack vs Zoom: Founders, CEOs and History
Slack was founded in 2009 by Stewart Butterfield, Cal Henderson, Eric Costello and is led by Rob Seaman (EVP & General Manager). Zoom was founded in 2011 by Eric Yuan and is led by Eric Yuan.
Company facts
Founders
Slack
Stewart Butterfield
Stewart Butterfield co-founded Tiny Speck in 2009 and led its pivot from the game Glitch to Slack.
Cal Henderson
Cal Henderson co-founded Slack in 2009 (originally Tiny Speck). Before Slack, he co-founded Flickr alongside Stewart Butterfield.
Eric Costello
Eric Costello co-founded Slack in 2009. Having previously worked with Butterfield and Henderson at Flickr, he helped build the absolutely critical early client-side architecture for the failed video game 'Glitch,' which ultimately pivoted into the massively su…
Serguei Mourachov
Serguei Mourachov co-founded Slack in 2009. Another veteran of the Flickr engineering team, he played an absolutely vital role in building the early backend systems for the company's failed gaming venture, providing the technical foundation that was rapidly re…
Zoom
Eric Yuan
Eric S. Yuan founded Zoom in 2011 and has been its CEO ever since. He took the company public in 2019, led it through the 2020 remote-work surge and the security fixes that followed, and has since pushed it into phone, contact center and AI products.
CEOs and their tenures
Slack
- Stewart Butterfield2009–2022
Co-Founder & Former CEO
As the visionary Co-Founder and former CEO, he completely revolutionized modern corporate communication, deeply embedding Slack's quirky, consumer-like design into the rigid enterprise software space.
Source - Denise Dresser2023–2025
Chief Executive Officer
As the current CEO (and former Salesforce executive), she acts as the absolute corporate anchor, tasked with heavily monetizing Slack within massive Fortune 500 enterprise accounts.
Source - Lidiane Jones2023–2023
Chief Executive Officer
Serving as CEO for less than a year in 2023, she attempted to stabilize the company following the massive exodus of the original founding team.
Source - Rob Seaman2025–present
EVP & General Manager, Slack
Slack chief product officer who took over Denise Dresser's duties on an interim basis in December 2025 and was named EVP & GM of Slack in February 2026; led the Slackbot launch and the March 2026 AI feature release.
Source
Zoom
- Eric Yuan2011–present
Founder & Chief Executive Officer
Has led Zoom from startup to a company with about $5 billion in annual revenue, and is now pushing growth through Enterprise sales and AI products.
Source - Michelle Chang2024–present
Chief Financial Officer
Joined from Microsoft, where she had been CFO of Microsoft Teams, and became Zoom's CFO on October 7, 2024, succeeding Kelly Steckelberg.
Source
Timeline: Slack and Zoom side by side
2009Slack
Tiny Speck Founded in San Francisco
Stewart Butterfield and co-founders established Tiny Speck to build multiplayer game Glitch.
2011Zoom
Zoom founded
Eric Yuan founded Zoom in San Jose after leaving Cisco Webex.
2012Slack
Glitch Closes & Internal Chat Pivots to Slack
Glitch ceased operations, prompting the team to commercialize their internal communication utility.
2013Slack
Private Beta Launch Earns 8,000 Signups in 24 Hours
Released private beta preview, igniting viral word-of-mouth adoption across Silicon Valley tech startups.
2013Zoom
Zoom Launches
Zoom Video Communications launched its video-conferencing product in 2013.
2014Slack
Official Public Launch & Fast-Track Unicorn Status
Launched publicly, reaching a $1.1B valuation in eight months as the fastest-growing enterprise app in history.
2015Slack
$2.8 Billion Valuation
Slack raised $160 million in April 2015 at a $2.8 billion valuation.
2017Slack
Launch of Slack Enterprise Grid for Fortune 500
Introduced Enterprise Grid, unlocking large-scale deployments for IBM, Target, and Capital One.
2017Zoom
Series D at $1 Billion Valuation
Zoom raised $100 million from Sequoia Capital in January 2017 at a $1 billion valuation.
2019Slack
NYSE Direct Listing (WORK)
Listed directly on the New York Stock Exchange on June 20, 2019.
2019Zoom
Nasdaq IPO
Zoom listed on Nasdaq as ZM.
2020Slack
Salesforce Announces $27.7B Acquisition Agreement
Marc Benioff announced Salesforce's landmark $27.7 billion acquisition of Slack to create Customer 360's digital HQ.
2020Zoom
Remote-work surge
Usage soared during the pandemic, and Zoom ran a 90-day security overhaul.
2020Zoom
Acquired Keybase
Zoom Communications acquired Keybase.
2021Slack
Acquisition Closes & Integration with Salesforce Begins
Salesforce completed the acquisition on July 21, 2021.
2021Zoom
Five9 deal ends
Five9 shareholders rejected Zoom's all-stock acquisition offer.
2022Zoom
Zoom Contact Center launched
Zoom launched its own contact-center product.
2023Slack
Denise Dresser Appointed CEO & Launch of Slack AI
Denise Dresser succeeded Lidiane Jones in December 2023 as Slack AI and Canvas rolled out.
2023Zoom
Acquired Workvivo
Zoom Communications acquired Workvivo.
2024Zoom
Renamed Zoom Communications
The company dropped "Video" from its legal name in November 2024.
2025Slack
Dresser Departs; AI Bundled Into Plans
Slack folded AI features into paid plans in 2025, and Denise Dresser left for OpenAI in December.
2025Zoom
Acquired BrightHire
Zoom Communications acquired BrightHire.
2026Slack
Slackbot Becomes a Personal AI Agent
Slackbot reached general availability in January 2026, followed by 30 AI features announced in March.
2026Zoom
Common Room deal and Q2 fiscal 2027 results
Zoom agreed to buy Common Room in July and reported Q2 revenue of $1.277 billion in August.
Acquisitions
Slack
- Rimeto2020Undisclosed
- Astro Technology2018Undisclosed
- Missions (from Robot & Pencil)2018Undisclosed
- Screenhero2015Undisclosed
Zoom
- Common Room2026Undisclosed
- BrightHire2025Undisclosed
- Workvivo2023Undisclosed
- Keybase2020Undisclosed
Questions about Slack vs Zoom
Who is the CEO of Slack Technologies, LLC and Zoom Communications, Inc.?
Slack Technologies, LLC is led by Rob Seaman (EVP & General Manager) and Zoom Communications, Inc. is led by Eric Yuan. Both serve as the top executive responsible for the company's strategy, operations, and financial performance.
When was Slack Technologies, LLC founded vs Zoom Communications, Inc.?
Slack Technologies, LLC was founded in 2009 — 2 years before Zoom Communications, Inc., which was founded in 2011. Slack Technologies, LLC's longer operating history gives it a deeper track record but also potentially more institutional inertia compared to the younger Zoom Communications, Inc..
How many employees does Slack Technologies, LLC have compared to Zoom Communications, Inc.?
Zoom Communications, Inc. employs approximately 7,400 people. A verified employee count for Slack Technologies, LLC is not currently available.
Where are Slack Technologies, LLC and Zoom Communications, Inc. headquartered?
Both Slack Technologies, LLC and Zoom Communications, Inc. are headquartered in United States. Their local rules and tax obligations may still differ.
Who founded Slack Technologies, LLC and Zoom Communications, Inc.?
Slack Technologies, LLC was founded by Stewart Butterfield, Cal Henderson, Eric Costello, Serguei Mourachov. Zoom Communications, Inc. was founded by Eric Yuan.
Which company has a longer operating history — Slack Technologies, LLC or Zoom Communications, Inc.?
Slack Technologies, LLC has been operating for approximately 17 years, making it the more established of the two companies. Zoom Communications, Inc. has been in operation for around 15 years. A longer operating history often signals greater institutional resilience and brand recognition, though it can also mean slower adaptation to new market conditions.
Figures come from each company's filings and the sources linked beside them. Amounts reported in another currency are shown in US dollars at an approximate rate and marked with ~. Back to the Slack vs Zoom overview