Houston founder shares how he's using tech to make digital media more effective and equitable

houston innovators podcast episode 173

This month, Mark Walker is celebrating his company's one year anniversary of going public — only the ninth Black-founded business to accomplish this feat on a U.S. stock exchange. Photo courtesy

After working in both sides of the advertising world, Mark Walker thought he could reimagine a platform that would be more efficient and equitable.

Walker co-founded his company, Direct Digital Holdings, an adtech platform, after serving in several roles — from an early hire at Houston digital media startup Questia to business development director at NRG Energy and COO of EBONY Media. He shares on the Houston Innovators Platform how he took this experience in tech, advertising, and media to create his company's platform.

"NRG Energy gave me a top-down view of the value chain, and Ebony gave me a bottoms-up view of the value chain of how media is purchased," Walker says on the show. "At Direct Digital Holdings, we help companies buy and sell media — and we leverage technology to do it. It's really the culmination of both of those experiences."

With over 30,000 publishers on its platform, Direct Digital makes it easier for its core customers — middle market companies looking to buy into the digital media ecosystem — to tap into these opportunities without the tech know-how they might otherwise need. Walker explains that at EBONY, he saw how small to midsize publications — especially the multicultural ones — were being left out on the ad selling side of the equation. The Direct Digital platform bridges the gap on each end.

Founded in 2018 in partnership with Keith Smith, who went through similar professional experiences, Direct Digital went public exactly one year ago after growing the company through strategic M&A activity. Walker says the decision to IPO made the most sense for his company — though it wasn't an easy process. Direct Digital is only the ninth company founded by a Black entrepreneur to go public on a US stock exchange.

"If you think the process is hard — it actually is," Walker says on the journey to IPO. "We were a privately held company, and we knew we had a good growth trajectory and we looked a couple different options. We decided to go public in a very traditional way."

Walker explains there were some risks involved, but the co-founders ultimately decided to shy away from adding in investors who might not have the same ideas for the company's future.

Direct Digital has been a Houston company from the star — despite the city not being home to a booming adtech ecosystem. Instead, Houston — with its collection of Fortune 500 companies and rich diversity — has allowed the business to stand out.

"If you look at and reflect on how our company has been built — from our board of directors to our leadership and management team — we're a majority minority organization all the way across the board," Walker says. "Diversity is very important to us. It's the lifeblood of our business — especially because we're serving publishers in those communities in big way. And moreso, we think you get the best product, thoughts, and ideas from a diverse workforce, and Houston fits right into that mold for us."

Walker shares more about his company's future, advice on IPO, and what all he's watching in adtech — from AI to streaming — on the podcast. Listen to the interview below — or wherever you stream your podcasts — and subscribe for weekly episodes.


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Baylor, Rice win $500,000 to launch humanities-driven health AI center

ethical AI

Baylor College of Medicine and Rice University have been awarded a $500,000 grant from the National Endowment for the Humanities (NEH) to create the Center for Humanities-based Health AI Innovation (CHHAIN).

The new center and three-year initiative aims to create ethically responsible and trustworthy AI for health care that uses history and patient narratives to shape the technology, according to a release. It represents a collaboration between the Center for Medical Ethics and Health Policy at Baylor and the Medical Humanities Research Institute at Rice. Ultimately, the researchers aim to establish a national model for integrating the humanities into the design and implementation of health AI.

Vasiliki Rahimzadeh, assistant professor at Baylor in the Center for Medical Ethics and Health Policy, and Kirsten Ostherr, director of the Medical Humanities Research Institute at Rice, will serve as co-directors of the new center, which will be housed within the Center for Medical Ethics.

The team will also engage in strategic collaborations with Kirstin Matthews, Rice’s Baker Institute for Public Policy and its fellow in science and technology policy, as well as Dr. Quianta Moore, executive director of the Meadows Mental Health Policy Institute. An interdisciplinary team of medical humanities and bioethics scholars from Baylor, Rice, and partners in the Houston area will complete the group.

“CHHAIN represents a bold new model for integrating the humanities into health innovation,” Ostherr said in a news release. “It will create a collaborative space where humanities scholars, patients, developers and clinicians can come together to explore the human dimensions of health AI—trust, narrative and lived experience. These are essential perspectives that are too often missing from technology development, and CHHAIN is designed to change that."

CHHAIN’s work will revolve around three key points:

  • Defining trustworthy AI through patient voices
  • Translating humanities insights into clinical AI settings
  • Public engagement and policy translation

“For AI to truly improve health outcomes, it must be designed with patient trust and wellbeing at its core,” Rahimzadeh said in the news release. “CHHAIN will provide a dedicated space to explore critical bioethics questions, such as how we ensure AI respects patient autonomy, addresses the needs of underserved communities and integrates meaningfully into clinical care. Our goal is to translate these insights into real-world health settings where AI is already shaping patient experiences."

CHHAIN's research mission was also developed thanks to pilot funding from the Margaret M. and Albert B. Alkek Department of Medicine at Baylor and a grant from Rice's Provost's TMC Collaborator Fund.

Texas A&M, the University of North Texas and the University of Texas at El Paso were also home to some of the 97 projects that received a portion of the $34.79 million in fundning from the NEH. See the full list here.

Houston booms as No. 2 U.S. market for retail construction in 2025

Construction Zone

Get ready for a gigantic cartload of new shopping opportunities in Houston. A new report indicates the equivalent of 21 Walmart supercenters is under construction in the region.

The report, published by commercial real estate services provider Lee & Associates, says Houston has nearly 3.9 million square feet of retail space under construction, making it the second most active market for new retail space in the U.S.

To put that in perspective, given the average Walmart supercenter measures 182,000 square feet, the 3.9 million-square-foot total would work out to 21 new supercenters being built in the region.

Dallas-Fort Worth is by far the most active U.S. market for new retail space; DFW leads more than 60 U.S. retail markets with nearly 7.15 million square feet of space under construction. The amount of retail space going up in DFW represents 15 percent of all retail space under construction in the more than 60 U.S. markets tracked by Lee & Associates.

Houston and Austin aren’t too far behind Dallas-Fort Worth, though.

Third-ranked Austin area has more than 3.4 million square feet of retail space being built.

What’s behind the surge in retail construction across Texas? Population growth.

Data recently released by the U.S. Census Bureau shows Houston was the second-fastest-growing metro from 2023 to 2024. DFW was the country’s third-fastest-growing metro from 2023 to 2024, based on the number of new residents, and Austin landed at No. 13.

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This article originally appeared on CultureMap.com.

Intuitive Machines to acquire NASA-certified deep space navigation company

space deal

Houston-based space technology, infrastructure and services company Intuitive Machines has agreed to buy Tempe, Arizona-based aerospace company KinetX for an undisclosed amount.

The deal is expected to close by the end of this year, according to a release from the company.

KinetX specializes in deep space navigation, systems engineering, ground software and constellation mission design. It’s the only company certified by NASA for deep space navigation. KinetX’s navigation software has supported both of Intuitive Machines’ lunar missions.

Intuitive Machines says the acquisition marks its entry into the precision navigation and flight dynamics segment of deep space operations.

“We know our objective, becoming an indispensable infrastructure services layer for space exploration, and achieving it requires intelligent systems and exceptional talent,” Intuitive Machines CEO Steve Altemus said in the release. “Bringing KinetX in-house gives us both: flight-proven deep space navigation expertise and the proprietary software behind some of the most ambitious missions in the solar system.”

KinetX has supported deep space missions for more than 30 years, CEO Christopher Bryan said.

“Joining Intuitive Machines gives our team a broader operational canvas and shared commitment to precision, autonomy, and engineering excellence,” Bryan said in the release. “We’re excited to help shape the next generation of space infrastructure with a partner that understands the demands of real flight, and values the people and tools required to meet them.”

Intuitive Machines has been making headlines in recent weeks. The company announced July 30 that it had secured a $9.8 million Phase Two government contract for its orbital transfer vehicle. Also last month, the City of Houston agreed to add three acres of commercial space for Intuitive Machines at the Houston Spaceport at Ellington Airport. Read more here.

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