Thirst things first

Dehydration is unimaginable when you have easy access to water, like contemplating starvation after stuffing your face at a banquet. Comforted by the modern convenience of taps, for example, medical symptoms such as headaches, dizziness and irrational behaviour have the insubstantial reality of a rumour.

Concentrate on your lips and you can begin to gain a sense of how it might feel, though. Lips are a focal point for what happens to the whole body when it begins to dry out: this tiny patch of skin turns to dust, a sandstone cleft leading into a desert cave.

I am standing in Solitaire, a small junction in the middle of the Khomas Region of central Namibia, home to innumerable cactuses, stripped cars, and a sad-looking petrol pump. Something has gone terribly wrong. At Windhoek Airport I discovered that my Mastercard didn't work, the ATMs siding exclusively with Visa. No matter, I figured, there would be other opportunities, but it didn't really pan out that way. Now I'm on the edge of a seemingly infinite desert, with little more than a cracked tongue, half a litre of water, and the fluttery beginnings of a shoplifting fantasy.

Dust flavours the air here and coats everything in a patina of grime. Cars shudder along unsealed roads and leave a trail of smoke as though they're on fire or disintegrating before your very eyes. The landscape is wide swatches of single colours - blue, yellow, red - that destroy all sense of distances and time, so you are driving and going nowhere, or merely slouching into oblivion. I have come here to camp, which feels appropriately transient for a place in endless states of erasure. But first: that question of water. The machine beeps, regurgitating paper. The woman narrows her eyes. Then she hands over a pen with an impatient wave of the hand: sign here, stupid man. With a valuable lesson learnt, I've been granted the liquid means to stave off death for another few days.

Even then, water is rarely far from my mind. The Tsauchab River, beginning in the southern Naukluft Mountains, is what is known as an "ephemeral stream", meaning it exists only in the rare instances of desert rain. While the Tsauchab may be an elusive sight, its effects have become legend: the ghostly salt pan of Sossusvlei, which fills up as a desert lake; Sesriem Canyon, carved by the river over centuries; and Deadvlei, strangest of all with its black, twisted trees and surrounding walls of sand. Devoid of moisture, this place is defined by it anyway.

The next day I wake at 4am, already coated in dust from evening winds blowing through the tent flaps. Within an hour I'm in a traffic queue at Sesriem gate, waiting for the Namib-Naukluft Park to open. Rounding out the trifecta of challenges here is the heat; it has become something of a rite of passage for visitors to climb Dune 45 before the sun turns the sand into a shimmering hotplate.

The Namib-Naukluft Park features some of the tallest dunes in the world, including the 325-metre Big Daddy. As sand blows east from the Atlantic Ocean, it collects in graceful mounds, the iron content oxidising and turning everything a rich apricot. Dune 45 is, unsurprisingly, 45 kilometres from the Sesriem gate, and when I reach it a horde of people is already climbing its 170-metre spine to watch the sunrise. It's a little incongruous to be confronted by so many visitors this early in the morning; pushing further on and facing away into the dunes restores a sense of solitude. The light rolls over the plains and shadows stretch to breaking point, fading on the ground like patches of plastic card.

Within hours temperatures have soared, but I am adamant about walking to the Tsauchab's most famous creation, the "dead marsh", or Deadvlei. Unlike Sossusvlei, which attracts flamingos when filled with water, this salt pan has long since declined as a place of refuge in the desert. Hundreds of years ago the river flooded the area, allowing camel thorn trees to take root in the sand. When it stopped flowing, however, the ground cracked into dramatic white plates and the trees seared black beneath the unrelenting sun. The result is something like an abstract painting, other-worldly and baffling. In The Cell, Hollywood used Deadvlei to represent the mental landscape of a serial killer. Jennifer Lopez wandered around it in a daze. Walking into the gnarled grove, I find myself doing something similar. All signs of life quickly fall away: the springboks, the hardy shrubs, the beetles with legs long enough to hoist their abdomens above the roasting sand. All that remains is silence and a pervasive sense of dread that has me clutching my water bottle like a crucifix.

Indeed, one small mistake is all it would take to send a person to their death here. The dunes surrounding Deadvlei are a moving maze. Earlier, I passed a car that had become hopelessly bogged in the sand, resisting the exertions of a team of sweat-drenched volunteers. Even balloon expeditions, floating high overhead in the early morning, are careful not to tempt fate by drifting too far into the desert. Human interaction is the equivalent of people on a beach, enjoying the ocean without paddling any further than the shallowest surf. Except everything here is reversed - the ocean is sand, and the beach is the precious domain of water. After fitful sleep through the hottest hours, I re-emerge in the late afternoon for a final foray to Sesriem Canyon, a short distance from my campsite near Sesriem gate. From above it looks like a jagged slash in the desert floor, nearly a kilometre long and between 20 metres and 50 metres deep.

Carved by the Tsauchab River millions of years ago, this odd formation was once the key to survival by local inhabitants and passing travellers. Sesriem means "six ropes": since a rope was originally made from the hide of an oryx, it took six, tied end to end, to reach the canyon floor where water could be retrieved for the pack animals using buckets.

My tent hits 46 degrees. Naturally occurring water seems as unlikely here as dehydration in a monsoon. But I descend into the shadow of the canyon, where birds have scratched nests into pockets of soft stone. And appreciating this respite from the sun, I spy a tepid pool alive with catfish. Truth be told, had my Mastercard not come through at Solitaire, I would, at this moment, jump fully clothed into the pool and refuse to move until the rains return.

 One of Gild’s customers is Square, a San Francisco-based mobile payment system. Like many other high-tech companies, Square is aggressively hiring, and it’s finding the competition for great talent as intense as it was during the dot-com boom, according to Bryan Power, the company’s director of talent and a Silicon Valley veteran. Mr. Power says Gild offers a potential leg up in finding programmers who aren’t the obvious catches.

“Getting out of Stanford or Google is a very good proxy” for talent, Mr. Power said. “They have reputations for a reason.” But those prospects have many choices, and they might not choose Square. “We need more pools to draw from,” he said, “and that’s what Gild represents.”

Gild’s technology has turned up some prospects for Square, but hasn’t led directly to a hire. Mr. Power says the Gild algorithm provides a generalized programming score that is not as specific as Square needs for its job slots. “Gild has an opinion of who is good but it’s not that simple,” he said, adding that Square was talking to Gild about refining the model.

Despite the limited usefulness thus far, Mr. Power says that what Gild is doing is the start of something powerful. Today’s young engineers are posting much more of their work online, and doing open-source work, providing more data to mine in search of the diamonds. “It’s all about finding unrecognized talent,” he said.

MR. DOMINGUEZ has worked at Gild for eight months and has proved himself a talented programmer, Mr. Desai said. But he also said that Mr. Dominguez “sometimes struggles to work in a structured environment.” His co-workers try not to bug him when he’s sitting at his computer, locked into that work zone.

In meetings, Mr. Dominguez speaks his mind. He’s happier, he said, “as long as I can have a say in how the system is built,” or it’s just another system he would have to conform to. He bristles slightly at the growth of the company, which has expanded to 40 people from 10 in the last six months, adding layers of management and bureaucracy.

“The truth is that’s in my nature to do stuff in my own way; inevitably I want to start my own company,” he said, but he’s quick to add: “I do appreciate and the respect the opportunity the company’s given me because I think it’s very clear they hired me on merit. I will always appreciate that.”