Investment Professionals

Mr. Sandeep Guleria (Partner) joined Siris in 2012. Sandeep serves on the Investment Team with responsibility for sourcing, executing, and managing investments across the technology sector. Sandeep serves on the firm's Investment and Operating Committees and currently oversees the firm's investments in Gigamon and Newfold Digital. Prior to Siris, Mr. Guleria worked in the Mergers and Acquisitions and Global Communications groups at Citigroup in New York. He graduated from New York University where he received a B.Sc. with a concentration in Finance and Accounting.

Mr. Dave Calamai (Managing Director) joined Siris in 2023. Prior to joining Siris, Mr. Calamai was a Principal at Tailwind Capital, where he focused on investments in the technology services, healthcare services, and business services sectors. Prior to his time at Tailwind, Mr. Calamai worked in the healthcare investment banking group at Morgan Stanley. Mr. Calamai received a B.A. in Biology and a M.S. in Commerce from the University of Virginia.

Mr. Kevin O'Brien (Principal) rejoined Siris in 2019 as a Senior Associate. Prior to joining Siris, Mr. OBrien was a Senior Director of Corporate Development and Finance at Pulse Secure (a Siris portfolio company) and Research Analyst at Point72 Asset Management, where he focused on public equity investments in the Technology, Media and Telecommunications industries. Prior to that, he was an Associate at Siris and an Analyst at Morgan Stanley. Mr. OBrien graduated from the University of Notre Dame, where he received a B.B.A. in Finance and Economics.

Mr. Grant Weisberg (Principal) joined Siris in 2018. Prior to joining Siris, Mr. Weisberg was an Investment Banking Analyst in the Mergers & Acquisitions Group at Credit Suisse in New York. Mr. Weisberg graduated from University of Chicago where he received a bachelor's degree in Economics and a minor from the Booth School of Business.

Mr. John Abram (Vice President) joined Siris in 2024. Prior to joining Siris, Mr. Abram was a Senior Associate at Shamrock Capital, where he focused on investments in the media, communications, marketing, technology and tech-enabled services sectors. Prior to his time at Shamrock, he was an Investment Banking Associate in the Financial Sponsors Group at Deutsche Bank. Mr. Abram graduated from Duke University where he received a B.Sc. in Economics with a concentration in Finance and a Certificate in Markets and Management Studies.

Mr. Matthew Montaquila (Vice President) joined Siris in 2021. Prior to joining Siris, Mr. Montaquila was an Investment Banking Analyst in the Technology, Media, and Telecommunications Group at Guggenheim Securities in New York. Mr. Montaquila graduated from University of Michigan with a B.B.A. from the Stephen M. Ross School of Business.

Ms. Jordan Iannone (Vice President) joined Siris in 2022. Prior to joining Siris, Ms. Iannone was an Investment Banking Analyst in the Technology, Media, and Telecommunications Group at Guggenheim Securities in New York. Ms. Iannone graduated from The Wharton School of the University of Pennsylvania where she received a B.S. in Economics, with concentrations in Finance and Business Economics and Public Policy and minored in Political Science.

Mr. PJ Shalhoub (Vice President) joined Siris in 2022. Prior to joining Siris, Mr. Shalhoub was an Investment Banking Analyst in the Technology, Media, and Telecommunications group at Rothschild & Co in New York. Mr. Shalhoub graduated from Boston College, where he received a B.A. in Mathematics as well as a minor in Hispanic studies.

Mr. Tiger Chen (Senior Associate) joined Siris in 2023. Prior to joining Siris, Mr. Chen was an Investment Banking Analyst at The Foros Group in New York. Mr. Chen graduated from Princeton University where he received a B.S.E. in Operations Research and Financial Engineering.

Mr. Daniel Cockerill (Associate) joined Siris in 2024. Prior to joining Siris, Mr. Cockerill was an Investment Banking Analyst in the Technology Group at Barclays in San Francisco. Mr. Cockerill graduated from the University of North Carolina at Charlotte where he received a B.S.B.A. in Finance and from Vanderbilt University where he received a M.S. in Finance.

Mr. David Mathai (Associate) joined Siris in 2025. Prior to joining Siris, Mr. Mathai was an Investment Banking Analyst in the Media & Telecom Group at Rothschild & Co. in New York. Mr. Mathai graduated from the University of Maryland where he received a B.S. in Finance and a Master of Finance.

Mr. Gavin Viegas (Associate) joined Siris in 2024. Prior to joining Siris, Mr. Viegas was an Investment Banking Analyst in the Mergers & Acquisitions Group at Oppenheimer & Co. in New York. Mr. Viegas graduated from Northeastern University where he received a B.S. in Business Administration and Mathematics, with a concentration in Finance.