When Hugh Martin agreed to lead a start-up working to revolutionize the outdoor LED lighting field, he knew he needed one thing.

No, not a fresh pair of Dockers, a catchy name for the company or even a new business card. What he needed was Kevin Hester, a programming savant whom Martin had worked with at three other companies that he'd run or helped run over the past two decades.

"Before I joined the company, I knew I needed Kevin, because he's brilliant; he's had tons of experience. He's entrepreneurial," says Martin, CEO of Sensity Systems, a Sunnyvale start-up that emerged from stealth mode Wednesday. In short, Hester was just what the start-up ordered.

When people say Silicon Valley is a small town, this is the sort of thing they mean. Call it a bromance, a high-tech hook-up or good business sense, the valley is a place that lends itself to second acts -- for individuals, sure, but also for people who have teamed up in the past and find the possibility of doing it again irresistible. (Think of the PayPal Mafia model, in which a cast of characters graduated from the online payment company and went on to start LinkedIn, Yelp, Tesla and a host of other companies, often relying on PayPal colleagues to invest or fill key roles.)

Hester's mission this time (and yes he chose to accept it) was to help Martin with a company that is renaming itself (from Xeralux) and reshaping itself from an outfit focused on LED lighting to one that plans to install LED lights and wireless network capabilities in street lights and outdoor light fixtures at shopping malls, airports, cities, corporate campuses and on and on. The promise of Sensity's lights is that paired with a processor and relying on a stable of software applications, they will be able to dim themselves and turn themselves off and on. They'll be able to report when they're burnt out or damaged. They'll be equipped to sense ground movement, becoming an earthquake monitoring system.

Depending on a customer's preference, Martin says, the light system can provide video surveillance, weather data, traffic monitoring, parking information; carbon monoxide levels, or it can be programmed to recognize the sound of breaking glass, gun shots or even screams -- all helpful security tools. And all the data will be uploaded to the cloud where it can be stored and endlessly crunched for trend-spotting.

The 42-employee company, which is operating some beta systems, is looking at shopping centers and parking garages as key customers. It's partnering with energy-management companies to sell its systems to cities. And it just reached an agreement with El Salvador, which will use Sensity systems at schools, a major airport, in some cities and on highways. Sensity, for its part, intends to establish factories in El Salvador. Martin is scheduled to meet with El Salvador President Carlos Mauricio Funes Cartagena in Washington D.C. on Thursday to dot i's and cross t's.

Martin, 59, a valley veteran with stints at Apple (AAPL) and Kleiner Perkins Caufield & Beyers, had a vision that was enough to lure Hester from a job he'd just started: working on Android technology at Google (GOOG). Yes, Google -- free gourmet food, massages, luxury buses-to-work, Endless Pool, sleep pods, rich financial rewards. A place that mere mortals would kill to work at. But Hester isn't a mere mortal. And beyond Martin's vision, there was the chance to work again with the old boss.

"It's hard to find a CEO, who is both sort of aggressive and non-duplicitous," Hester, 46, says. It's sort of that Goldilocks thing. Some CEOs, Hester says, are admirably honest, but wishy-washy. Others are maniacal in their focus, so much so that they shed their honesty in pursuit of success and profit. Martin, you could say, was just right.

At any rate, there was no question that Hester knew what he was getting. They worked together at 3DO, a video game company where Martin was president; and then at optical networking company ONI and gene-sequencing company Pacific Biosystems, both of which Martin took public as CEO.

Sure, they took some breaks. ("I work for other CEOs sometimes," Hester says.) Every bromance needs a break. But time and again, Martin and Hester ended up working together.

Santa Clara University psychology professor Jerrold Shapiro, who's also a practicing psychologist, says he's familiar with the pattern and has seen it in clients over the years. There are practical business considerations involved, he says: Bosses and employees like certainty in each other. If it worked once, it's reasonable to think it will work again. But Shapiro, who has written about and often speaks on men's issues, thinks there is more to it.

"You're looking at a very powerful form of male bonding," Shapiro says. "Men tend to do that very well. When you find a connection, they last a very long time. And they may be in and out, and go back and forth, but there is that kind of deep relationship of trust and work that propels people forward and it keeps repeating during life."

Could be. Martin has a simpler way of putting it.

"What I would say about Kevin," he says, "is that if there is a significant software component to what I'm doing or to what I think the company should be doing, he's No. 1 on my list."

This time and every time.

Contact Mike Cassidy at mcassidy@mercurynews.com or 408-920-5536. Follow him at Twitter.com/mikecassidy.