PubNub Leadership Team

  • Todd Greene
    Founder & CEO

    As an entrepreneur who has founded and successfully sold companies across the software spectrum, Todd helps shape the PubNub vision of revolutionizing the way people interact online. Todd most recently was CEO of Loyalize, an Audience Participation company successfully sold to Function(x) (FNCX), a Robert F.X. Sillerman company, where he designed the first-ever massively multi-user Social TV mobile and web applications licensed to companies like Viacom and Yahoo. Todd previously was founder and CTO/VP Products of CascadeWorks, a company providing Services Procurement solutions to Texas Instruments, Charles Schwab, and ABN Amro, and acquired by Elance. After working with companies like GE, SGI, and Quantum while a consultant at Price Waterhouse, Todd joined NetDynamics (sold to Sun Microsystems in 1998) to help create a truly game-changing product: the first application server built for the Internet.

  • Stephen Blum
    Founder & CTO

    Stephen's vision and strong technical chops drove the initial architecture of PubNub, building a core engine that has successfully scaled to the some of the largest realtime deployments in the world. Stephen has been a successful software entrepreneur his whole life, starting his first company, LTSun, at age 17, and joining Microsoft after its acquisition. Stephen was the chief architect for, a 50-language social recommendations site that grew to over 1 million users across over 100 countries.

    Chief Financial Officer

    Marc has played key roles in both software startups and as an investor and entrepreneur. Marc served as Chief Operating Officer and CFO at Intalio, a enterprise software company, where he led finance, marketing, sales operations and administration for a growing team. A 15-year veteran of the venture industry, Marc has served in General Partner roles at USVP and Summit Partners and as a Venture Partner at Partech International. He made investments in ground-breaking companies in internet infrastructure including NetDynamics, Check Point Software, Blue Martini Software and Marc earned an MBA from Harvard Business School and his bachelor's and master's degrees in Electrical Engineering from Massachusetts Institute of Technology

    VP of Customer Success

    Assaf brings over 20 years of experience in pre and post sales leadership and management. Prior to PubNub, Assaf led Customer Success, Professional Services and Solution Consultants functions at companies such as Zendesk (IPO in May 2015), eMeter (acquired by Siemens), IBM and Amdocs. Assaf began his high-tech career as an engineer, system-admin, DBA and was responsible for managing high growth teams. Assaf is happiest when customers achieve their goals, and believes that a great customer experience is paramount. When not managing PubNub's Center of Excellence, Assaf can be found playing the piano, training new generations of soccer referees and spending time with family. He holds a Bachelor degree in Business and Finance from Bar-Ilan University, Israel.

  • Jeff Green
    VP of Engineering

    Jeff is an industry veteran with over 25 years of experience in building software for enterprises and consumers. He has a proven track record of building world-class products and technologies for companies such as Pulse Secure (divested from Juniper), Juniper Networks, McAfee (acquired by Intel), Dr Solomon’s (acquired by McAfee), ItsOn, Octel (acquired by Lucent) and Clearswift. Jeff has a strong history in the security industry. He was instrumental in delivering the first mass scale anti-virus cloud-based technology named Artemis at McAfee as well as being instrumental in responding to Melissa the first major email-borne virus. When not building products Jeff can be found playing with home automation or tinkering/building cars. Jeff is a graduate in Computer Science from the University of East Anglia in the UK.

  • Casey Clegg
    VP Sales

    Casey has over a decade of experience building developer-focused sales teams. Prior to joining PubNub, Casey was part of the sales leadership team at Twilio that drove 15x growth in revenue over five years culminating in the 2016 IPO. Before that, Casey started and built the API business unit at Yodlee, growing the division to half of all revenues in the years leading up to the company's IPO. Originally hailing from the Bronx, by way of the Chicago suburbs, Casey lives in the Bay Area with his wife and two sons. Casey is a graduate of New York University and has an MBA from UCLA Anderson.


John Occhipinti
Board Member, Relay Ventures

John is a Partner at Relay Ventures, an early stage venture fund exclusively focused on mobile software. John has over 20 years of experience in enterprise software technology, marketing, and sales. Previously he was Managing Director of Woodside Fund where he focused on ventures in cloud computing, online advertising technology and software. John presently sits on the boards of Appcelerator, PubNub, Rally, and advises Graffiti Lab.

Andy Vitus
Board Member, Scale Venture Partners

Andy is a Partner at Scale Venture Partners (ScaleVP). Andy focuses on ScaleVP’s investments in next-generation enterprise software and new point of presence technologies – including virtualization and cloud computing. Prior to joining ScaleVP, Andy worked as a hardware engineer for Electronics for Imaging, designing embedded print server platforms and video compression circuits. Andy sits on the boards of Arena, Boundary, DataStax, Entone, PubNub, and INNOViON.

Zack Urlocker
Board Member

Zack is an executive, investor, advisor and board member with over twenty years of experience in the software industry. He has helped scale revenues in startups from under $6 million to over $100 million and has had multiple billion dollar exits. He has held executive positions at Borland, Active Software, MySQL and most recently as Chief Operating Officer at Zendesk. He is a frequent speaker on disruptive technology and occasional marathon runner.

Prashant Shah
Board Observer, TiE Angels

Prashant is Managing Director of TiE LaunchPad, an accelerator for enterprise startups. He is an active Charter Member of TiE Silicon Valley (, a member of its Board of Directors, and Head of TiE Angels. Prashant Shah has been an early stage venture investor since 2001. Previously, he spent nearly 10 years at Hummer Winblad Venture Partners, an early stage VC focused on enterprise and infrastructure software.

Jai Das
Board Observer, Sapphire Ventures

Jai is a Managing Director at Sapphire Ventures. His primary focus is in the areas of software-defined infrastructure, cloud and mobile computing, smart machines, IoT and pervasive analytics. Jai has more than 15 years of experience helping companies innovate their product and marketing strategies in order to scale and become market leaders. He has led and manages the firm’s investments in Alteryx, Box (BOX), Cyphort, Five9 (FIVN), Justdial (JUSTDIAL), Mirantis, Mulesoft, Narrative Science, Nutanix, PayTM, PubNub, Socrata and Square.

Luis Llovera
Board Observer, Robert Bosch Venture Capital GmbH

Luis is an employee of Robert Bosch LLC. He is a non-executive board director of RBVC’s portfolio companies Nextreme and Ogmento. Prior to joining Bosch in 2008, Luis was an Investment Partner for over 6 years with Siemens Venture Capital. Some of his investments included Agility Communications (acquired by JDSU), PubNub, GENBAND, Covega (acquired by Gemfire) and Polychromix. Luis has over 17 years of operating experience in the hi-tech industry.

Amit Chaturvedy
Board Observer, Cisco Investments

Amit leads global venture investing and M&A efforts in Internet of Things. Prior to Cisco, Amit was at Summit Partners where he led investments in Fleetcor (NYSE: FLT), MA-Com (NASDAQ:MTSI) and Rocket Internet (ETR: RKET). Previously, he was at Cummins Inc. where he led software development and product marketing activities. Amit also worked in investment banking at Citigroup, NY. He has led and managed Cisco’s investments in Ayla, Bitstew,, McRock Capital, PubNub, relayr and Veniam.

Albert Kim
Board Observer

Albert is the head of Ericsson's corporate venture capital group, based in Silicon valley. He represents Ericsson as a non-executive director on the boards of Pluribus Networks and Pubnub, and also manages Ericsson's investment in Drawbridge. Prior to joining Ericsson in 2014, Albert was a Managing Director at Investor Growth Capital, where he spent over 13 years in growth stage venture capital. Albert has a PhD in Applied Physics and also dabbled in banking (Goldman Sachs) and consulting (McKinsey) before joining IGC.

Stephen Zocchi

Stephen is the Founder and CEO at Allayo, a mobile health assistant platform for adherence and wellness that connects health care and consumers. A start-up veteran with a proven record of building successful companies, his experience includes two company IPOs and 2 acquisitions. Prior to Allayo, lead the growth of Model N from $13M to $65M as SVP of Sales and VP of Marketing. Previous experience also included VP Marketing at CascadeWorks, VP of Marketing and Business Development at NetDynamics.

Anshu Sharma

Anshu is a software industry executive with over 15 years of experience at leading enterprise software companies like Oracle and Most recently, he served at Salesforce for over 5 years as the vice president of products for Salesforce Platform where he led Salesforce's entry into Java platform as a service, Identity Management, Database as a service and next generation marketing platform. As an angel investor in early stage ventures and advisor to leading venture firms, Anshu works with strong engineering and product teams to define their go to market and long term product strategy.

Greg Simon

Greg likes to work on disruptive technologies and products. Previously he created webOS at Palm -- blurring the lines between native and web. Prior to that he kicked-off the iPod/automobile integration fad by creating the BMW iPod adapter. While still in grad school he wrote the web browser engine for the Apple Newton. Currently Greg leads the team working on the Blink web rendering engine at Google that powers Chrome, Chrome OS, and many other browsers.

Doron Sherman

In a career spanning 25 years, Doron co-founded and served in technical executive roles in software companies that made critical contributions to the enterprise software and internet infrastructure industries. He co-founded and was Chief Scientist of NetDynamics, a leading application server pioneer (acquired by Sun in 1998), CTO of Collaxa, inventor of the BPEL web services orchestration server (acquired by Oracle in 2004) and Director of Kindling, a high-participation venture management fund specializing in Internet/B2B startups.