Gartner Expert

Mark O'Neill

VP Analyst

Mark O'Neill is a VP Analyst and Chief of Research for Software Engineering. He guides Gartner's insights on software development, application architecture, and frameworks and tools for building software, spanning key initiatives in Gartner for IT Leaders as well as Gartner for Technical Professionals. Mark also leads Gartner's API Strategy research community. With his security and startup background, his own research focus includes API security and the new wave of API-first companies. Mark is a frequent conference speaker and webinar presenter.

Previous experience

Mr. O'Neill is the author of the book "Web Services Security" and other guidance on API security and strategy. He also co-founded two companies, acting as CTO at both. At Vordel, as CTO, he drove API gateway strategy, leading to its acquisition.

Throughout his career, Mr. O'Neill has worked closely with software engineering teams, enterprise architects, CIOs and security professionals, providing best-practice guidance on API security strategy, API and integration strategy, and API management.

Professional background


VP Innovation


CTO and Co-founder

Delphium Technologies

CTO and Co-founder

Areas of coverage

Applications and Software Engineering Leaders

Software Engineering Technologies

Software Engineering Practices


B.A., Mathematics and Psychology, Trinity College, Dublin

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Top Issues That I Help Clients Address

1API management including API gateways and API portals

2API security using standards such as OAuth and OpenID Connect

3API integration with iPaaS and ESB

4Banking APIs, including PSD2

5Microservices architecture, service mesh, and how it relates to APIs and SOA