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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Rice University partners with astronaut foundation to offer new STEM scholarship

space scholars

Rice University has partnered with The Astronaut Scholarship Foundation (ASF) to offer a new scholarship opportunity for junior or senior STEM majors, beginning this spring.

The prestigious Astronaut Scholarship includes up to $15,000, mentorship, networking and a paid trip to the ASF Innovators Symposium and Gala. The scholarship is funded by the James A. Lovell Jr. Family Endowment, in honor of the late American astronaut and founder of the ASF.

“This scholarship opportunity represents an exciting new avenue for Rice STEM students to synthesize their experiences in courses and research and their commitment to advancing the public good as leaders in their field,” Danika Brown, executive director for the Center for Civic Leadership at Rice, said in a news release. “We are so grateful to the Lovell family and to the foundation for investing in Rice students, and we are confident that the foundation will be impressed with our nominees and that selected students will have a life-changing experience as astronaut scholars.”

The Rice Space Institute and the Center for Civic Learning recently hosted the ASF at the Ralph S. O’Connor Building for Engineering and Science.

At the ASF event, Jeff Lovell—son of James Lovell, who commanded Apollo 13 and flew on Apollo 8—announced the scholarship aimed at Rice STEM students. Charlie Duke, who served as spacecraft communicator for the Apollo 11 Moon landing and as the lunar module pilot for Apollo 16, also spoke at the event.

The ASF awarded 74 scholarships to students from 51 universities across the U.S. last May.

The ASF awarded its first seven $1,000 scholarships in 1986 to pay tribute to the Mercury 7 astronauts. It has since awarded more than $10 million to more than 850 college students.

So far, only students from Texas A&M University and the University of Texas at Austin have received the scholarship in Texas.

Houston hospital first in U.S. to use new system for minimally invasive surgery

sharper images

Houston’s Baylor St. Luke’s Medical Center has introduced an innovative new surgical imaging system that will allow surgeons to increase the number of minimally invasive procedures as well as reposition on the fly during operations.

Minimally invasive surgery has been shown across the board to improve patient outcomes with less chance of infection and shorter recovery times compared to traditional open surgery. However, the human body is not exactly easy to work on through small incisions, necessitating the development of state-of-the-art cameras and imaging technology to guide surgeons.

Enter GE HealthCare’s Allia Moveo, now a part of the Baylor St. Luke’s Medical Center operating room. Using cutting-edge technology, it uses the same high-definition imaging usually seen in the catheterization lab at speeds fast enough to respond to shifting surgical conditions. Its cable-free setup allows surgeons to switch positions much faster, and it features advanced 3D imaging that compensates for breathing motion and interference from metal implants.

Its design supports a range of cardiovascular, vascular, non-vascular, interventional and surgical procedures, according to CommonSpirit Health, a nonprofit Catholic health network, of which Baylor St. Luke's is a member.

“This innovative platform enhances how our clinicians navigate complex minimally invasive procedures by improving mobility, image clarity, and workflow efficiency. It strengthens our ability to deliver precise, patient-centered care while supporting our teams with technology designed for the evolving demands of modern interventional medicine,” Dr. Brad Lembcke, president of Baylor St. Luke’s Medical Center, said in a news release from Baylor and the Texas Heart Institute.

Baylor St. Luke’s is the first hospital in the U.S. to use the Allia Moveo technology. The definition and responsiveness of the new system allow surgeons to navigate the body with greater accuracy and smaller incisions, even for very delicate operations.

“Allia Moveo gives us the flexibility and image quality needed to manage increasingly complex minimally invasive procedures with greater confidence,” Dr. Gustavo Oderich, vascular surgeon and professor of surgery at Baylor College of Medicine, added in the release. “The ability to quickly reposition the system, obtain high-quality 3D imaging, and integrate advanced guidance tools directly into the workflow enhances procedural accuracy. This technology supports our mission to push the boundaries of what is possible in endovascular and interventional surgery.”

Houston clocks in as one of the hardest working cities in America

Ranking It

Houston and its residents are proving their tenacity as some of the hardest working Americans in 2026, so says a new study.

WalletHub's annual "Hardest-Working Cities in America (2026)" report ranked Houston the 37th most hardworking city nationwide. H-town last appeared as the 28th most industrious American city in 2025, but it still remains among the top 50.

The personal finance website evaluated 116 U.S. cities based on 11 key indicators across "direct" and "indirect" work factors, such as an individual's average workweek hours, average commute times, employment rates, and more.

The U.S. cities that comprised the top five include Cheyenne, Wyoming (No. 1); Anchorage, Alaska (No. 2); Washington, D.C. (No. 2); Sioux Falls, South Dakota (No. 4); and Irving, Texas (No. 5). Dallas and Austin also earned a spot among the top 10, landing as No. 7 and No. 10, respectively.

Based on the report's findings, Houston has the No. 31-best "direct work factors" ranking in the nation, which analyzed residents' average workweek hours, employment rates, the share of households where no adults work, the share of workers leaving vacation time unused, the share of "engaged" workers, and the rate of "idle youth" (residents aged 16-24 that are not in school nor have a job).

However, Houston lagged behind in the "indirect work factors" ranking, landing at No. 77 out of all 116 cities in the report. "Indirect" work factors that were considered include residents' average commute times, the share of workers with multiple jobs, the share of residents who participate in local groups or organizations, annual volunteer hours, and residents' average leisure time spent per day.

Based on data from The Organisation for Economic Co-operation and Development (OECD), WalletHub said the average American employee works hundreds of more hours than workers residing in "several other industrialized nations."

"The typical American puts in 1,796 hours per year – 179 more than in Japan, 284 more than in the U.K., and 465 more than in Germany," the report's author wrote. "In recent years, the rise of remote work has, in some cases, extended work hours even further."

WalletHub also tracked the nation's lowest and highest employment rates based on the largest city in each state from 2009 to 2024.

ranking

Source: WalletHub

Other Texas cities that earned spots on the list include Fort Worth (No. 13), Corpus Christi (No. 14), Arlington (No. 15), Plano (No. 17), Laredo (No. 22), Garland (No. 24), El Paso (No. 43), Lubbock (No. 46), and San Antonio (No. 61).

Data for this study was sourced from the U.S. Census Bureau, Bureau of Labor Statistics, U.S. Travel Association, Gallup, Social Science Research Council, and the Corporation for National & Community Service as of January 29, 2026.

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This article originally appeared on CultureMap.com.

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