Mark Jacobstein

CEO

Stanford, California, United States27 yrs 9 mos experience

Key Highlights

  • Pioneered the first online fantasy sports business.
  • Led successful sale of iSkoot to Qualcomm.
  • Co-founded multiple AI-driven health and venture companies.
Stackforce AI infers this person is a seasoned entrepreneur in Healthcare and Telecommunications, with a strong focus on AI and user engagement.

Contact

Skills

Core Skills

User ExperienceCorporate StrategyFundraisingProduct ManagementMobile VoipBusiness Development

Other Skills

RecruitingGo-to-market StrategyMarketingSalesSocial MediaPartnershipsVenture CapitalCorporate DevelopmentLeadershipStrategic ThinkingPublic SpeakingMobile DevicesMobile ApplicationsStrategic PartnershipsStart-ups

About

Mark has built and run companies at the forefront of new technologies for thirty years. In 1994, he founded Small World Sports, the world’s first online fantasy sports business, which he later sold to Paul Allen’s The Sporting News. In 1995, he spun out one of the world’s first web agencies, Small World Software, which he sold to iXL before its 1998 IPO. In 2003, Trip Hawkins convinced Mark to move to the Bay Area to co-found Sequoia and Kleiner Perkins-backed mobile games pioneer Digital Chocolate. Mark was then recruited to join loopt as the “adult supervision” for Sam Altman (Sam didn’t need any supervision). Later, Vinod Khosla recruited Mark to run mobile VOIP pioneer iSkoot, which he sold to Qualcomm in 2010. Mark spent four years as the Chief User Engagement Officer at Guardant Health, which raised more than $500M before its 2019 IPO, and was the CBO for Immunai, a world-leading AI-driven biotech operating at the intersection of machine learning and genomics that raised more than $300M during Mark’s tenure. In 2023, Mark co-founded Jimini Health, which is leveraging LLMs and cutting-edge science to develop radically more effective, engaging, and scalable mental health solutions. In 2023, Mark co-founded Near Horizon to pioneer a new approach to venture building. Near Horizon partners with entrepreneurs at company formation to build AI-powered companies, providing both capital and hands-on help. Mark has advised or invested in numerous startups, including Gerson Lehrman Group, Gusto, Elation EMR, Akash Network, SafeGraph, and Luminopia. Mark earned his BA from Harvard, where he concentrated in Computer Science. He lives on the Stanford campus with his wife and two (adorable) daughters.

Experience

27 yrs 9 mos
Total Experience
2 yrs 8 mos
Average Tenure
9 mos
Current Experience

South park commons

2 roles

General Partner

Promoted

Feb 2026Present · 3 mos · San Francisco, California, United States

Visiting Partner

Aug 2025Feb 2026 · 6 mos · San Francisco, California, United States

Second

Venture Builder

Sep 2024Sep 2025 · 1 yr · San Francisco Bay Area

  • Second automates all of your codebase maintenance, including upgrades (React 18 -> 19, Python 3.10 -> 3.14) and migrations (Angular -> React). We can free your engineering team to spend more time on your product, all for the fraction of the cost of a single engineer. Let's get started today, reach out for more information.

Jimini health

Co-Founder and President

Sep 2023Present · 2 yrs 8 mos · New York, United States · Remote

  • Jimini’s mission is to radically improve the efficacy of mental health care. We are starting by building an AI-augmented therapy model, where we have redesigned the entire patient journey, creating a clinically effective, more modern treatment for patients.
  • Learn more and sign up at jiminihealth.com
  • As co-founder and President, I work across many aspects of the business, including user experience, corporate strategy, recruiting the senior team and scientific leadership, and GTM.
User ExperienceCorporate StrategyRecruitingGo-to-market Strategy

Sanctum, inc.

Venture Builder

Sep 2023Present · 2 yrs 8 mos · Remote

Sleuth

Advisor

Aug 2023Present · 2 yrs 9 mos

Near horizon

Co-founder and General Partner

Jul 2023Sep 2025 · 2 yrs 2 mos · Palo Alto, California, United States · Hybrid

  • Near Horizon is pioneering a new approach to venture building. We partner with entrepreneurs at company formation to build AI-powered companies, providing both capital and hands-on help
FundraisingProduct ManagementMarketingSalesRecruiting

Numerous

Executive Business Advisor and stay-at-home dad

Jan 2023May 2023 · 4 mos · Remote

Immunai

2 roles

Executive Business Advisor at Immunai

Apr 2022Apr 2023 · 1 yr

  • Part-time business advisor for Immunai and stay-at-home dad.

Chief Business Officer

Oct 2020May 2022 · 1 yr 7 mos

Odin

Board Member

Nov 2020Feb 2026 · 5 yrs 3 mos

Biden cancer initiative

Co-Chair Working Group on Data Access

Jan 2019Jul 2019 · 6 mos

  • Co-chair, along with Anish Chopra (ex-CTO of America) of the BCI workgroup on data access.

Luminopia

Board Member

Feb 2018Present · 8 yrs 3 mos

Guardant health

Chief User Engagement Officer

Jul 2015Jul 2019 · 4 yrs · Redwood City, CA

  • Guardant Health (https://www.guardanthealth.com/) is the world’s leader in “blood biopsies”: blood tests that track tumor genomics and identify treatment options.
  • As CUEO I was responsible for ensuring that Guardant's products are engaging for all of our customers – not only our physicians, but also our patients, their families, advocates, and anyone whose life is touched by cancer. I also oversaw our marketing department, working to advance our brand as the world’s leader in liquid biopsies, identifying new products for the product portfolio, and supporting sales in their efforts to reach the oncology community.

No longer on sabbatical

Chief Sabbatical Officer

Jan 2013Jun 2015 · 2 yrs 5 mos · San Francisco Bay Area

  • Largely working with technology startups:
  • Angel Investor in companies including Gerson Lehrman Group (Silverlake), VoiceStar (Marchex), Lab Pixies (Google), Shopular, Disconnect, ZenPayroll, ElationEMR, Nuzzle, AngelList, Alta Motors, Artivest, Finomial, DietBet, Scoot Networks, Cambrian Genomics, reTargetter, Aperia Technologies, PURETi, Expedite Financial, and Vaultive.
  • Active advisor for numerous technology startups, including: Flixster (Time Warner), Flurry (Yahoo!), Scribd, Progreso Financiero, Helios Retinal Prosthesis, Expedite Financial, Knotch, Coub, DoubleTwist, StartX, Frank, AppCoin, Locket, Venture for America, and Trailhead Labs.

Full circle fund

Board Member

Jan 2011Jun 2017 · 6 yrs 5 mos · San Francisco Bay Area

Qualcomm

VP Product Management

Oct 2010Jan 2013 · 2 yrs 3 mos · San Francisco Bay Area

  • Qualcomm acquired iSkoot in October 2010. During my lockup I ran the iSkoot group inside Qualcomm. Also:
  • Created an IP-communications platform leveraging both iSkoot’s technology and Qualcomm’s existing QChat product line. Designed to underpin new mobile services requiring easy-to-implement, high-quality, low latency mobile VoIP and messaging services.
  • Created a wireless data optimization platform that reduced data traffic and latency in cellular data environments. Leveraging Qualcomm’s unique position as a provider of both mobile silicon and cellular RANs, the product delivered sizable improvements in network efficiency by compressing and optimizing at the edge of the network, and decompressing in the http stack on the device.

Iskoot

CEO

Dec 2007Oct 2010 · 2 yrs 10 mos · San Francisco Bay Area

  • Brought in by board members from Khosla Ventures and Charles River Ventures to raise $20M series C financing and drive company forward. Led successful sale of the company to Qualcomm. Highlights of tenure included:
  • Expanded mobile Skype initiatives with both 3/Hutch and direct-to-consumer
  • Raised $20M series C during difficult fundraising environment
  • Leveraged iSkoot’s proxy server architecture to build mobile social media product
  • Structured partnerships with Twitter, Facebook, MySpace, and others to bring social media product to market. Leveraged these relationships to gain access to unique and privileged APIs from Facebook and Twitter
  • Sold iSkoot’s mobile social media product to many Tier 1 operators, including AT&T, T-Mobile, Verizon, Telefonica, Hutch/3, and Vodafone; leveraged these operator relationships into dozens of preload opportunities on tens of millions of devices
  • Ran M&A process with several bidders, leading to successful sale to Qualcomm

Charles river ventures

Entrepreneur in Residence

Aug 2007Nov 2007 · 3 mos · Palo Alto, CA

  • Developed wireless health startup plan; was recruited to run iSkoot, a CRV company
FundraisingMobile VoIPSocial MediaPartnerships

Loopt, inc.

EVP Corporate Development & Marketing

Jan 2006Jul 2007 · 1 yr 6 mos

  • I was responsible for a variety of functions for loopt, a Palo Alto-based start up developing the world's first "social mapping" software for mobile phones.

Digital chocolate

President of Publishing, co-Founder

Dec 2003Dec 2005 · 2 yrs · San Mateo

  • My primary responsibility was running the global publishing business for Digital Chocolate. I oversaw the entire product development process, from concept to launch, for our two international studios, and helped close our first two rounds of financing from Sequoia, KPCB, and Sutter Hill.

Advantage capital

Entrepeneur in Residence

Jan 2003Jan 2003 · 0 mo · Greater New York City Area

Sporting news

VP Wireless and iTV

Jan 2001Jan 2002 · 1 yr · Greater New York City Area

  • Integrated Small World Sports, world's first online fantasy sports business, into Paul Allen's Sporting News business following our acqusition. Oversaw iTV strategy for TSN as well.

Ixl

SVP

Jan 1998Jan 2000 · 2 yrs

  • Ran Business Development for iXL's NYC office from the time of iXL's acquisition of Small World Software (which I co-founded and ran) through iXL's successful IPO.
FundraisingBusiness DevelopmentVenture Capital

Small world software

Founder and Partner (de facto co-CEO)

Apr 1994Jan 1998 · 3 yrs 9 mos · Greater New York City Area

  • Founded one of the first web agencies / Internet solution companies in the world. Small World Software was a successful spin-off from Small World Sports (my fantasy sports business). I sold Small World Software to iXL in 1998 in advance of iXL's IPO.

Small world sports

CEO

Jan 1994Jan 2002 · 8 yrs · Greater New York City Area

  • Founded and ran the world's first online fantasy sports business. Started business in 1994 in my living room, predating the birth of the commercial internet, and built 100+ person company that raised $20M+ in VC from firms including Flatiron, NBCi, and Chase Capital Partners before selling company to Paul Allen's Sporting News.

Education

Harvard University

B.A. — Computer Science with Cognitive Science

Jan 1988Jan 1992

Stackforce found 100+ more professionals with User Experience & Corporate Strategy

Explore similar profiles based on matching skills and experience