The incubator for Czarina Walker’s budding business was a closet in the foyer of her mother’s home in Baton Rouge. Walker was 19.

The young software designer was the only employee for more than two years for what would become InfiniEdge Software in Prairieville.

Over her first 12 months of entrepreneurship, the LSU student — then known as Czarina Ahmad — designed custom software for clients who paid her a combined total of between $30,000 and $40,000.

“Not bad for a teenager,” the 37-year-old said recently.

Last year, she and husband, Brad Walker, 41, led InfiniEdge to total sales of more than $2.9 million.

That’s before payroll, taxes, health insurance and other expenses, Brad Walker quickly added.

Those sales remain impressive, though, and Inc. magazine twice has listed InfiniEdge as one of the 5,000 fastest-growing companies of all types in the United States. This year, because of the Prairieville firm’s sales growth of 48 percent in 2013, it was ranked 4,813.

Much of that growth is due to the couple’s focus on custom development of software for both businesses and government entities, the partners said.

“If someone comes to us, it’s got to be something that is unique,” Brad said.

“We don’t want to re-invent the wheel,” Czarina said. “We write the blueprints for (specialized) software.”

That approach demands critical thinking skills.

“You can’t say, ‘It can’t be done.’ ” Brad said.

“Let’s go through the process of how you do business,” Brad said, adding that potential clients are advised from the start.

“We’ve taken a warehouse that had about 33 people packing and unpacking,” Brad recalled of one customer. “Another 10 were in office administration.”

InfiniEdge designed software that enabled the company to reduce its warehouse staff to eight or nine, he said.

Because the company was undergoing rapid growth, Czarina said, no jobs were lost. She said employees removed from the warehouse were immediately assigned other tasks.

Other companies and government agencies have hired InfiniEdge to develop specialized collection programs, prepare specifications for projects to be awarded through a bid process and create document-management systems.

One of the firm’s more unusual projects, Czarina said, was development of a system for tracking an endangered bird species. A client then used the system to determine whether the bird was endangered by a bomb or artillery range at Fort Polk near Leesville.

InfiniEdge’s growth has occurred without the benefit of advertising.

The Walkers said their firm’s website and recommendations from satisfied clients have attracted enough new business to keep them busy.

Because they’re always exploring new digital frontiers, both owners said, they and InfiniEdge employees constantly are working to solve problems they are encountering for the first time. That broadens their experiences and sharpens their skills.

That love of discovery is not limited to their professional lives.

Both halves of the Walker household are active in the Prairieville and Baton Rouge-area business, education and nonprofit communities — all while raising two children.

Czarina is a board member of the Baton Rouge Area Chamber. Brad is on the board of both the Ascension Parish Chamber of Commerce and the Ascension Fund, which raises money for teachers’ classroom needs.

Both are active with the Dancing for a Cause fundraiser for Community Opportunities of East Ascension, which seeks jobs for residents with disabilities.

The Walkers also helped begin the technology club for fifth-graders at Spanish Lake Primary School.

“They go above and beyond what you usually see most companies do,” said Mike Eades, president and chief executive officer of the Ascension Economic Development Corp. “They’re both very involved in the community. They’ve done a lot for the parish.”

Other Louisiana residents have helped them, the Walkers said. InfiniEdge has received project-based tax credits from the Louisiana Department of Economic Development, Czarina said.

“Since 2008, InfiniEdge has earned a total of $423,847 in cumulative software development tax credits,” said Stephen Moret, the state’s secretary for economic development.

That state funding, in turn, has helped InfiniEdge employ more people on more software development projects, Czarina said.

A core group of about 20 employees expands for months at a time to meet the demands of one or more projects, she added.

This year, Brad said, the number of InfiniEdge employees has ranged from 20 to 55.

Czarina said volunteer work with students from fifth grade to college has given her a greater appreciation for teachers and helped her find better ways to explain problem-solving techniques to young people.

Technology wasn’t an attention-grabbing term for fifth-graders in an after-school club, Czarina said. So, those students were encouraged to help develop and test software for a food-group game.

Game was an attention-grabbing term for those young minds.

“They didn’t realize they were learning math,” Czarina said. “They learned health, too. All kinds of things were learned in that hour and a half.”

The next computer game “was a lemonade stand,” Czarina said. “It was a neat interactive challenge for them. They learned about entrepreneurship. They learned math and technology.”

“We thought we would have 20 or 30 kids,” Brad said. “She wound up with 53.”

“Technology skills are as important today as reading and writing,” Czarina said. “Somewhere along the way, we forgot to talk to kids about this. Even if you want to be a farmer, there’s a ton of technology in agriculture.”

Louisiana’s technology industry is growing, the pair noted. There is, however, a shortage of qualified technology workers in the state.

With that shortage in mind, the Walkers said InfiniEdge participates in computer technology workshops at LSU and Southeastern Louisiana University in Hammond to assist students’ growth and scout for future employees.

“Czarina and Brad have been very instrumental in helping our students with internships and full-time jobs,” said Ghassan Alkadi, a professor of computer science at Southeastern.

“The Walkers have been coming for years to attend our students’ presentations in our senior Capstone course, as well as the software engineering I course, which plants the seeds of success and support for our students,” Alkadi said. “Czarina’s support and guidance is invaluable, as she always speaks to our students about latest trends and salient technologies.”

Louisiana residents should be proud of the pair, Alkadi said, because, “InfiniEdge and the Walkers are a successful combination.”

Alkadi added: “The students that worked and are still working at InfiniEdge always praise the working environment. They consistently say that it is a family-oriented place and provides great learning experiences.”

“We’ve hired so many from Southeastern,” Brad said. “And they know: If you’ve got InfiniEdge on your résumé, you can get a job anywhere in this state.”

“Southeastern is one of those bright, shining stories in our industry,” Czarina said.

Whether working with fifth-graders or college students, Czarina said she enjoys helping others learn about software design: “You’re creating a community of people who are not afraid to create their own stuff.”

Both Walkers said they love their work, and both said they became fascinated with computers when they were children.

Brad’s parents bought a computer before he entered East Ascension High School.

“Adults have a price tag attached to everything,” Brad said. “They have to.”

Brad didn’t have that concern, though. He immediately took the computer apart and then reassembled it.

“I might not have done that if I had known it cost $2,500,” Brad said, adding that the computer was not damaged by his examination of its internal workings.

After graduating from Baton Rouge Magnet High, Czarina enrolled in LSU but discovered she had lost her early interest in technology. She majored in pre-med and won an internship at Pennington Biomedical Research Center.

That’s where her childhood love of computer technology blossomed into a career calling.

“It turns out they write their own software at Pennington,” Czarina said. “I got my hands on technology that was not yet available to the general public. I realized: ‘Oh, wow! There’s really a demand for this.’ ”

That realization led to creation of her own software development company, and she left LSU 16 hours short of her degree.

Pennington provided more than intellectual fuel for creation of InfiniEdge. The research center was where Czarina met the man who would become both her husband and president of her company.

“I don’t think the ink was even dry on my new business cards, when I ran into Brad,” she recalled.

They met at a Baton Rouge Area Chamber technology exposition hosted by Pennington. She was looking for information to help grow her new company. He was manning an expo booth for his employer, a networking company.

Brad later left the networking company for Czarina’s young software firm.

In March, the Walkers said, they’ll celebrate the 19th birthday of their company.