IF California is a state of mind, then mobile app maker Mallzee’s bright, open-plan office is an exclave of the Sunshine State in central Edinburgh. Housed above a gay bar, its white walls are daubed with inspiring quotes in black paint.

There is Bruce Wayne, aka Batman: “Everything’s Impossible Until Someone Does It”. Thomas Edison: “Genius is 1% inspiration, 99% perspiration”. And, probably most appropriately for one of the capital’s myriad fast-growing technology start-ups: “Whatever you’re thinking, think bigger.”

The California vibe doesn’t end with the stirring slogans. When I visit on a weekday morning, half a dozen or so casually dressed web developers are deep in conversation about Mallzee’s mobile shopping app. All look under 30. One is sitting on a beanbag. I feel tragically unhip.

“If you are 25, 26, 27, you think anything is possible,” says Mallzee’s CEO Cally Russell, who is at the oldest end of that youthful age range. Russell was born in Dunoon but looks like he could have stepped out of The Social Network, David Fincher’s movie about Facebook. His sandy hair is slicked-back and his dress sense bellows smart causal: suit jacket, black jeans, Nike trainers.

With the flourish of a former PR man Russell talks me through the Mallzee app, which allows shoppers to browse clothes from more than 130 high street stores. “Some people describe it as the Tinder for fashion”. I haven’t the heart to tell him I don’t know how Tinder works. “Ah, I see,” I nod.

When it comes to Edinburgh’s tech scene, the product is not the only thing that takes time to understand. Almost everyone is praying for “angel investors” – cash-rich individuals who often finance start-ups – with “smart money” that will allow them to make great “plays” – disruptive entries into previously sealed markets.

There is hard cash behind the buzz-words. Earlier this year Mallzee, which launched in 2012, secured a partnership with tech giant Samsung – after Russell turned down an offer of £75,000 investment from Peter Jones on BBC’s Dragon’s Den. “Turning down money is always a difficult decision but we made the right decision,” he says with a smile.

The company has doubled its workforce to 16 in the last 12 months. Among investors is the CEO of Skyscanner, the Edinburgh-based flight comparison website.

Edinburgh is fast becoming one of the most popular cities in Europe for tech start-ups. The capital’s technology cluster is second only to London in the UK in terms of productivity, with big-hitters such as Amazon and Dell operating alongside dozens and dozens of small start-up companies.

Scotland’s computer games legacy has contributed to Edinburgh’s tech renaissance. Just down the road from Mallzee is Rockstar Games, the creators of Grand Theft Auto who will soon move into The Scotsman’s former offices near Holyrood. It’s hard to imagine a more succulent illustration of the rise of new media, and the collapse of the old.

Cally Russell welcomes the change. Unlike many established industries, the tech scene, with its regular meet-ups and camaraderie, is very open and supportive. “Some days you’re like, ‘this is awful’,” Russell says. “That’s why it is so good to be surrounded by other people who have all been there on that day when you feel ‘this might not be a flier’. They can help you.”

Edinburgh is attracting global tech talent. Among the earbudded heads bobbing in front of banks of Mallzee computers are developers from Sweden, Switzerland, Italy and further afield. “A lot of people come here to join the industry,” says Russell. “It’s seen that you can have a better quality of life than London. I hope that people will soon come to start businesses in Edinburgh in the way they do in Berlin, London or Dublin.”

ON the fourth floor of Argyle House, an ungainly 1960s-era office block in the shadow of Edinburgh Castle, a hirsute man in a T-shirt sits in front a computer. On the desk are a power drill and a glass chess set. “Welcome to CodeBase,” he smiles when I exit the lift into the brightly coloured lobby. “Have a seat.”

Incubators are a vital part of any start-up scene. These tech hubs allow new businesses find their feet, learn from one another and develop without the pressures of running a full office.

In Edinburgh, CodeBase is fast becoming the incubator of choice. “I built this in order to stop complaining about what is wrong with tech start-ups in this part of the world,” says its founder Jamie Colman.

Colman is the eminence grise of

Scotland’s startup scene. (One web developer described him to me as “the equivalent of the guy who sold shovels to the gold prospectors during the gold rush.”) In person, Coleman has echoes of Ming the Merciless: the same shaved head, the same goatee beard, the same supreme self-confidence as he talks through some of the more than 60 companies that have based themselves in what was once a social security office.

“This is all about talent-spotting for me,” says Colman. “I want to build more billion-dollar tech companies. Companies that can go from five people to 500. We can build them here.” On the shelves behind him are dozens of Scottish history books – biographies of Bonnie Prince Charlie, Tom Devine’s The Scottish Empire – and a pair of Raspberry Pis, the super-cheap, lightweight tiny computers that have transformed digital access. CodeBase is a distinctly Scottish face in a global digital revolution.

Coleman talks quickly, at one stage pointing at two graphs drawn on a whiteboard on his office wall. One is a standard model of a small business, showing slow, steady, linear growth. The other graph looks almost random, the curving line dipping below the x-axis before shooting off towards outer space. “The difference in our industry is the graph looks fundamentally different for the internet,” he say. “It’s capital intensive at the start but once you grow it’s on an exponential scale.”

The popular image of technology is Google and Facebook – companies that build products that the public use in spades – but much of Edinburgh’s success is business-to-business, companies selling lucrative tech products to doctors, restaurateurs and defence ministries. Many are spin-offs from research initiated in the city’s universities, particularly the world-leading School of Informatics at Edinburgh University.

As we walk through Argyle House’s dimly lit corridors, Coleman points out different start-ups that occupy almost every room. One makes “living infographics”, another “monitors outbound threats”. There are so many names I lose track. “There’s an event on in here,” Coleman says mysteriously as we pass a room with the blinds shut tight. On the next floor it sounds as if a light aircraft is taking off inside another room. The loud hum is from the banks of computer servers. “That’s the water that runs this place,” says Coleman.

TWO-and-a-half years ago, FanDuel was run out of cramped offices in Edinburgh University’s Appleton Tower. Now the fantasy sports game occupies half a floor of the sleek, glass-fronted Quartermile building. The office walls are decorated with US sporting memorabilia: baseball mitts and basketball shirts, American footballs. Television screens show rolling sports news. The business, which allows fans to compete with one another in fantasy sports leagues, is estimated to be worth more than $1billion.

“Technology is a sector that is ripe for entrepreneurship because you can create something totally new,” says Edinburgh University graduate Nigel Eccles, one of FanDuel’s five co-founders. The company expects growth to continue at 300% annually.

All of FanDuel’s business takes place in the US, due to differing interpretations of what constitutes betting in American and British legislation. But the company is evenly spread between Scotland and New York. “We built a very strong engineering base here in Edinburgh,” explains Eccles. The company now employs 180 staff and is “looking to double the headcount”. A Glasgow office will open soon.

Recruitment is one of the biggest problems in the tech sector – which partly explains why successful companies work so hard to create a satisfied workforce. FanDuel’s offices are like none I’ve ever been in. Smiling developers play table tennis and table football in the large games room. There are fridges stacked full of Coke, Doctor Pepper, even bottles of beer, and a seemingly endless supply of crisps, chocolate and dried fruit. Every month a big screen used for weekly Skype meetings is turned over for the staff film night.

Project manager Naomi Freireich used to work for Standard Life, but like many, left finance computing for tech. “This is the first time I’ve woken up in the morning and gone “Yay, work!” I just love it,” Freireich says. “They trust that you are professional. That’s really refreshing. I suspect people work harder because of that.”

Not every tech business in Edinburgh is a winner. Earlier this year the much-touted photo blogging site Blipfoto collapsed with the loss of 11 jobs. But there are clear signs of growth across the sector.

Adjacent to the Quartermile, men in hard hats are busy at work on another office block to keep up with demand for space from tech companies.

Despite its many successes, Scotland’s tech scene does not receive always receive the attention it deserves. Front-page stories about tech firms are rare. “There is an old-fashioned mind-set. Unless you’ve got 500 staff and a big factory, making something that people can hold in their hand, then you don’t count,” says Brian Baglow, founder of Scottish Games Network.

Companies such as Skyscanner and FanDuel are changing public perceptions, but there is one area where Edinburgh is still a world away from Silicon Valley – self-promotion. “There is an unwillingness to shout about what you’re doing, or even tell people,” says Baglow. “This is a very Scottish thing. ‘Talking about how good you are? That’s what confident people do. I’m not American for God’s sake!’”