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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Texas ranked among the top 10 best states to find a job, new report says

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If you’re hunting for a job in Texas amid a tough employment market, you stand a better chance of landing it here than you might in other states.

A new ranking by personal finance website WalletHub of the best states for jobs puts Texas at No. 7. The Lone Star State lands at No. 2 in the economic environment category and No. 18 in the job market category.

Massachusetts tops the list, and West Virginia appears at the bottom.

To determine the most attractive states for employment, WalletHub compared the 50 states across 34 key indicators of economic health and job market strength. Ranking factors included employment growth, median annual income, and average commute time.

“Living in one of the best states for jobs can provide stable conditions for the long term, helping you ride out the fluctuations that the economy will experience in the future,” WalletHub analyst Chip Lupo says.

In September, Gov. Greg Abbott announced Texas led the U.S. in job creation with the addition of 195,600 jobs over the past 12 months.

“Texas is America’s jobs leader,” Abbott says. “With the best business climate in the nation and a skilled and growing labor force, Texas is where businesses invest, jobs grow, and families thrive. Texas will continue to cut red tape and invest in businesses large and small to spur the economic growth of communities across our great state.”

While Abbott proclaims Texas is “America’s jobs leader,” the state’s level of job creation has recently slowed. In June, the Federal Reserve Bank of Dallas noted that the state’s year-to-date job growth rate had dipped to 1.8 percent, and that even slower job growth was expected in the second half of this year.

The August unemployment rate in Texas stood at 4.1 percent, according to the Texas Workforce Commission. Throughout 2025, the monthly rate in Texas has been either four percent or 4.1 percent.

By comparison, the U.S. unemployment rate in August was 4.3 percent, according to the U.S. Bureau of Labor Statistics. In 2025, the monthly rate for the U.S. has ranged from 4 percent to 4.3 percent.

Here’s a rundown of the August unemployment rates in Texas’ four biggest metro areas:

  • Austin — 3.9 percent
  • Dallas-Fort Worth — 4.4 percent
  • Houston — 5 percent
  • San Antonio — 4.4 percent

Unemployment rates have remained steady this year despite layoffs and hiring freezes driven by economic uncertainty. However, the number of U.S. workers who’ve been without a job for at least 27 weeks has risen by 385,000 this year, the Bureau of Labor Statistics reported in August. That month, long-term unemployed workers accounted for about one-fourth of all unemployed workers.

An August survey by the Federal Reserve Bank of New York showed a record-low 44.9 percent of Americans were confident about finding a job if they lost their current one.

Autonomous truck co. goes public and more innovation news to know

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Editor's note: It's time to catch up on the top Houston innovation news for the first half of November. From major investments to a big boost in dementia research, here are the most-read InnovationMap stories from Nov. 1-15, 2025:

1. Autonomous truck company with Houston routes goes public

Kodiak Robotics has formed Kodiak AI, whose stock now trades on the Nasdaq market. Photo via kodiak.ai.

Kodiak Robotics, a provider of AI-powered autonomous vehicle technology, has gone public through a SPAC merger and has rebranded as Kodiak AI. The company operates trucking routes to and from Houston, which has served as a launchpad for the business. Privately held Kodiak, founded in 2018, merged with a special purpose acquisition company — publicly held Ares Acquisition Corp. II — to form Kodiak AI, whose stock now trades on the Nasdaq market. Continue reading.

2. Venus Aerospace picks up investment from Lockheed Martin Ventures

Lockheed Martin Ventures says it's committed to helping Houston-based Venus Aerospace scale its technology. Photo courtesy Venus Aerospace

Venus Aerospace, a Houston-based startup specializing in next-generation rocket engine propulsion, has received funding from Lockheed Martin Ventures, the investment arm of aerospace and defense contractor Lockheed Martin, for an undisclosed amount. The product lineup at Lockheed Martin includes rockets. The investment follows Venus’ successful high-thrust test flight of its rotating detonation rocket engine (RDRE) in May. Venus says it’s the only company in the world that makes a flight-proven, high-thrust RDRE with a “clear path to scaled production.” Continue reading.

3. America's first Ismaili Center set to open in Houston in December

Nearly 20 years in the making, The Ismaili Center, Houston, opens in December 2025. Photo by Iwan Baan

The long-awaited Ismaili Center, Houston is set to open to the public next month. The 11-acre site has been painstakingly designed and constructed to offer indoor and outdoor public spaces for Houstonians to enjoy, connect, and engage. As the only Ismaili Center in the United States — and seventh in the world — it joins its international communities in London, Vancouver, Lisbon, Dubai, Dushanbe, and Toronto. Community welcome events are scheduled for December 12 and 13, but, until then, here are 10 features and things to know about the Ismaili Center, Houston. Continue reading.

4. Texas voters OK $3 billion for new dementia research institute

Thanks to the passage of Proposition 14, Texas now boasts the country’s largest state-funded initiative dedicated to dementia research and prevention. Photo via Unsplash.

Texas voters on Nov. 4 overwhelmingly approved a ballot measure that provides $3 billion in state funding over a 10-year span for the newly established Dementia Prevention and Research Institute of Texas (DPRIT). Thanks to the passage of Proposition 14, Texas now boasts the country’s largest state-funded initiative dedicated to dementia research and prevention, according to the Alzheimer’s Association. Up to $300 million in grants will be awarded during the 10-year funding period. Continue reading.

5. 2025 Houston Innovation Awards winners revealed at annual event

2025 Innovation Awards group photo2025 Houston Innovation Awards winners revealed at annual eventThe 2025 Houston Innovation Awards winners have been revealed. Courtesy photo

After weeks of anticipation, the 2025 Houston Innovation Awards winners have been revealed. Finalists, judges, and VIPs from Houston's vibrant innovation community gathered on Nov. 13 at Greentown Labs for the fifth annual event. This year, the Houston Innovation Awards recognized more than 40 finalists, with winners unveiled in 10 categories. Continue reading.

TMC, Memorial Hermann launch partnership to spur new patient care technologies

medtech partnership

Texas Medical Center and Memorial Hermann Health System have launched a new collaboration for developing patient care technology.

Through the partnership, Memorial Hermann employees and physicians will now be able to participate in the TMC Center for Device Innovation (CDI), which will assist them in translating product innovation ideas into working prototypes. The first group of entrepreneurs will pitch their innovations in early 2026, according to a release from TMC.

“Memorial Hermann is excited to launch this new partnership with the TMC CDI,” Ini Ekiko Thomas, vice president of information technology at Memorial Hermann, said in the news release. “As we continue to grow (a) culture of innovation, we look forward to supporting our employees, affiliated physicians and providers in new ways.”

Mentors from Memorial Hermann, TMC Innovation and industry experts with specialties in medicine, regulatory strategy, reimbursement planning and investor readiness will assist with the program. The innovators will also gain access to support systems like product innovation and translation strategy, get dedicated engineering and machinist resources and personal workbench space at the CDI.

“The prototyping facilities and opportunities at TMC are world-class and globally recognized, attracting innovators from around the world to advance their technologies,” Tom Luby, chief innovation officer at TMC Innovation Factor, said in the release.

Memorial Hermann says the partnership will support its innovation hub’s “pilot and scale approach” and hopes that it will extend the hub’s impact in “supporting researchers, clinicians and staff in developing patentable, commercially viable products.”

“We are excited to expand our partnership with Memorial Hermann and open the doors of our Center for Device Innovation to their employees and physicians—already among the best in medical care,” Luby added in the release. “We look forward to seeing what they accomplish next, utilizing our labs and gaining insights from top leaders across our campus.”

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