Apollo Appoints Mark Sieglock as Chief Product Officer

Former eero product and engineering leader joins Apollo to lead R&D as company builds the AI GTM system for the next generation of revenue teams

SAN FRANCISCO, Aug. 25, 2026 /PRNewswire/ -- Apollo, the AI go-to-market system, today announced the appointment of Mark Sieglock as Chief Product Officer. Sieglock brings a proven track record of scaling product and engineering organizations, most notably as an early product executive at eero. In his new role, Mark will lead Apollo's product strategy, design, research, and engineering organizations as the company accelerates its vision to build a connected, intelligent GTM system that helps every business find and win customers.

Mark brings deep experience building and scaling category-defining technology products. As a product executive at eero, he helped take the company from pre-product through the launch of its first product in 2016, its acquisition by Amazon in 2019, and ultimately into tens of millions of homes globally.

His appointment comes at a pivotal moment for Apollo and the broader GTM industry. Historically, sales and marketing organizations have relied on disconnected systems for customer data, outreach, marketing, pipeline management, and other revenue workflows. AI is creating an opportunity to fundamentally rethink that model by connecting those systems and turning customer signals into intelligent, coordinated action.

"Mark is one of the most talented product leaders I've encountered," said Matt Curl, CEO of Apollo. "He has built and scaled through category-defining shifts, and he understands what this moment represents for Apollo. We're building an AI GTM system that brings data, intelligence, and execution together so every business can find and win customers. Mark has the product vision, technical depth, and customer obsession to help us build that future."

At Apollo, Mark will focus on advancing a product strategy designed to move GTM beyond siloed systems and manual workflows. By connecting signals across sales, marketing, customer data, website activity, meetings, and other touchpoints, Apollo is building toward a system where AI can understand the full customer context, determine the next best action, and execute it across the revenue lifecycle.

"What drew me to Apollo is the opportunity to make a meaningful difference for the hundreds of thousands of businesses that rely on the platform every week," said Sieglock. "My immediate focus will be serving the more than 600,000 customers who use Apollo, listening closely to what they need and making sure we're consistently delivering world-class products that help them grow. AI is creating an opportunity to fundamentally improve how businesses find and connect with customers, and I'm excited to work with this team to make that technology powerful, approachable, and accessible to companies of every size."

Mark's appointment is the latest addition to Apollo's executive leadership team under Curl, following the appointment of Phil Moon as Chief Financial Officer in May. Together, the hires strengthen Apollo's leadership as the company continues investing in long-term growth and the evolution of its AI-native platform.

About Apollo.io
Apollo is the AI GTM System that uniquely combines data, intelligence, and execution in one loop helping every business find and win their next customer. Trusted by millions of users and over 600,000 companies worldwide, Apollo combines the industry's largest B2B contact database with a purpose built GTM intelligence engine and a full execution stack, in an all-in-one system that gets smarter with every interaction. Learn more at apollo.io.

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SOURCE Apollo.io