Three Houston companies have earned spots on this year's edition of the North American Technology Fast 500.

The three Houston honorees are:

• Enercross, a provider of logistics software for the energy sector. It appears at No. 31 on the Fast 500 list, with revenue growth of 6,230 percent from 2017 to 2020.
• Onit, which offers workflow and AI technology for legal, compliance, sales, IT, HR, and finance departments. It lands at No. 304, with a 408 percent rise in revenue from 2017 to 2020. According to Crunchbase, Onit has reeled in $216.6 million in venture capital.
• Graylog, a provider of log management software. It sits at No. 309, with revenue growth of 402 percent from 2017 to 2020. Graylog has collected $27.4 million in venture capital, according to Crunchbase. That includes an $18 million round announced this summer.

The North America Technology Fast 500, sponsored by professional services firm Deloitte, is an annual ranking of the fastest-growing tech, media, telecom, life sciences, and energy tech companies in North America.

"The Houston companies on this year's Fast 500 list are transforming the way our city does business by combining technological innovation with entrepreneurial spirit," Amy Chronis, Houston managing partner at Deloitte, says in a news release. "I'm inspired by the ways these organizations have succeeded amid unprecedented times, and I look forward to seeing their progress in 2022."

The top-ranked company is Irvine, California-based medical device company Axonics, whose revenue soared 87,037 percent from 2017 to 2020. The top-ranked Texas company is Austin-based Shipwell, where revenue climbed 32,670 percent from 2017 to 2020. Shipwell provides a shipment-tracking platform. Overall, 5 percent of the Fast 500 companies are based in Texas.

Both Enercross and Onit showed up on last year's Fast 500. Enercross ranked 37th in 2020, with revenue growth of 5,881 percent, and Onit ranked 190th, with revenue growth of 641 percent. Meanwhile, Graylog is a new entrant this year.

Two Houston companies fell off the Fast 500 this year:

• Lexicon Pharmaceuticals, which ranked 328th last year with revenue growth of 306 percent.
• Vendor Credentialing Services (symplr), a tech platform that simplifies vendor services, compliance, and more for health professionals. It appeared at No. 426 last year, notching revenue growth of 221 percent.

Not surprisingly, Silicon Valley accounted for one-fifth of the companies in this year's Fast 500, followed by the New York City metro area (12 percent) and New England (8 percent). Nearly three-fourths of the Fast 500 companies specialize in software, and 81 percent of the companies have received venture capital at some point.

"Each year, the Technology Fast 500 shines a light on leading innovators in technology, and this year is no exception," says Paul Silverglate, leader of the U.S. technology sector at Deloitte. "In the face of innumerable challenges resulting from the pandemic, the best and brightest were able to pivot, reinvent and transform and grow."