Where does Cal Henderson work?

Cal Henderson is Co-founder & CTO of Slack.

What companies has Cal Henderson invested in?

Investments tracked here include Dedalus Labs, OpenFoundry, Opusense AI, Pally, Tekton Dynamics.

Where did Cal Henderson go to school?

Cal Henderson studied at Birmingham City University (BSc, Software Engineering); Sharnbook Upper School.

Cal Henderson

InvestorUnicorn founder

Co-founder & CTO at Slack

San Francisco, CA

FoundedSlack$7.1B

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You →Luke · together at EMAP (2001) →Cal

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You →Jamie · together at Flickr →Cal

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You →Sam · 10 people · together at Slack →Cal

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About

Cal Henderson co-founded Slack in 2013 and has been its CTO throughout, having previously been an early engineer and architect at Flickr with Stewart Butterfield. He built the real-time messaging infrastructure that carried Slack from launch through a 2019 direct listing and the $27.7B Salesforce acquisition in 2021, and wrote Building Scalable Web Sites.

Co-founder & CTO at Slack

Intro paths

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In turn, Cal can intro founders to Slack's investors below.

Slack's investors · 54

1991 VenturesLondon · $504K checks AccelPalo Alto · $500K – $100M checks · since 2010 ACME CapitalSan Francisco Acrew CapitalSan Francisco · $1M – $15M checks Aglae VenturesParis · $108K – $5.4M checks Altos VenturesBurlingame · $1M – $3M checks Andreessen HorowitzMenlo Park · $500K – $50M checks · since 2010 Atlassian Ventures$1M – $5M checks Baillie GiffordEdinburgh · since 2018 Bloomberg BetaSan Francisco · $25K – $1M checks Bond Capital ManagementSan Francisco · $100K – $25M checks Coatue ManagementNew York · $1M – $20M checks Comcast VenturesNew York · $2M – $15M checks · since 2016 Craft VenturesSan Francisco · $50K – $50M checks Dragoneer Investment GroupSan Francisco · $100K – $5M checks · since 2018 DST GlobalGeorge Town, Grand Cayman · since 2015 EQUIAMSan Francisco · $1M – $10M checks Felicis VenturesSan Francisco · $500K – $15M checks FundersClubSan Francisco · $290K checks General AtlanticNew York · $10M – $1B checks · since 2018 Global Founders CapitalBerlin · $1M checks Glynn Capital ManagementMenlo Park GP BullhoundLondon Granite AsiaSingapore · $5M – $25M checks · since 2016 GV (Google Ventures)Mountain View · $250K – $50M checks · since 2014 High AlphaIndianapolis Horizons VenturesHong Kong · $500K – $10M checks · since 2015 Index VenturesSan Francisco · $540K – $10.8M checks · since 2015 IVP (Institutional Venture Partners)San Francisco · $15M – $75M checks · since 2015 Khosla VenturesMenlo Park · $100K – $20M checks Kleiner PerkinsMenlo Park · $500K – $15M checks · since 2014 Light Street CapitalPalo Alto Lowercase CapitalJackson MicroVenturesAustin · $150K – $1M checks Moonshots CapitalAustin · $5K – $2.5M checks Mudita VentureDetroit · $250K – $2M checks Next Play VenturesMenlo Park · $100K – $5M checks NFXSan Francisco · $250K – $5M checks · since 2021 Night CapitalCapitola Norwest Venture PartnersMenlo Park · $10M – $30M checks · since 2021 Notable CapitalSilicon Valley · $5M – $50M checks S32Palo Alto Section 32Palo Alto Slow VenturesSan Francisco · $50K – $1M checks SoftBank Vision FundLondon · since 2017 Spark CapitalSan Francisco · $500K – $25M checks · since 2015 SV AngelSan Francisco · $150K – $20M checks Thrive CapitalNew York · $500K – $25M checks · since 2016 TOP-Direct IVGeneva TriplePoint CapitalMenlo Park · $250K – $10M checks · since 2021 Unanimous CapitalMenlo Park Wellington ManagementBoston · $5M – $50M checks · since 2018 Westbound Equity PartnersPalo Alto · $750K – $2M checks · since 2021 Wireframe VenturesSan Francisco · $500K – $2M checks

Co-founders at Slack

Stewart ButterfieldCo-founder & CEO

Experience

Slack Technologies, IncCo-founder & CTO2009 — 2024San Francisco, CA
FlickrHead of Engineering2003 — 2009San Francisco Bay Area
EMAPDirector of Technology2001 — 2004Greater London, England, United Kingdom

Skills & more

CMS3JavaScript27Flash3APIs1Mobile Applications7jQueryPHP21MySQL4Web Applications13HTML 5Web Development37Scalability16

+12 more

SubversionUser ExperienceProgrammingSoftware DevelopmentCSSHTMLWeb ServicesRubyScrumFront-endOOPActionScript

From Cal's professional profile.

Investments

Investor

Dedalus Labs OpenFoundry Opusense AI Pally Tekton Dynamics

Per curated public sources.

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Podcasts & interviews

featuring Cal Henderson

Slush AgAIn | Cal Henderson (Slack) & Laura Modiano (OpenAI)

Slush

Cal Henderson: Co-founder @Slack, Workplace Productivity & Organizational Alignment | Slush 2024

Slush

Slack’s Founding Story | Cal Henderson (Slack) & Sarah Cannon (Coatue) | Slush 2023

Slush

#54 - Cal Henderson // CTO @ Slack - alphalist.CTO Podcast - For CTOs and Technical Leaders

alphalist

Slack CTO and Co-Founder Cal Henderson, 2019 GeekWire Cloud Summit

GeekWire

Building Software That People Love: Lessons from Cal Henderson, Slack Co-founder & CTO

Slush

Frequently asked questions

Who is Cal Henderson?: Cal Henderson co-founded Slack in 2013 and has been its CTO throughout, having previously been an early engineer and architect at Flickr with Stewart Butterfield. He built the real-time messaging infrastructure that carried Slack from launch through a 2019 direct listing and the $27.7B Salesforce acquisition in 2021, and wrote Building Scalable Web Sites.
Where does Cal Henderson work?: Cal Henderson is Co-founder & CTO of Slack.
What companies did Cal Henderson found?: Cal Henderson founded Slack.
What companies has Cal Henderson invested in?: Investments tracked here include Dedalus Labs, OpenFoundry, Opusense AI, Pally, Tekton Dynamics.
Where did Cal Henderson go to school?: Cal Henderson studied at Birmingham City University (BSc, Software Engineering); Sharnbook Upper School.
What podcasts and interviews feature Cal Henderson?: Tracked appearances include "Slush AgAIn | Cal Henderson (Slack) & Laura Modiano (OpenAI)", "Cal Henderson: Co-founder @Slack, Workplace Productivity & Organizational Alignment | Slush 2024", "Slack’s Founding Story | Cal Henderson (Slack) & Sarah Cannon (Coatue) | Slush 2023", and 3 more.