An entrepreneurial journey that started from nothing in Istanbul, twenty years with the world's biggest brands, and AI technology being built in London today. Serhat Gürcü and Seden Gürcü are siblings who turned what they learned in advertising into global technology companies. ADIN.AI, the company they co-founded, was named Türkiye's fastest-growing technology company by Deloitte and ranked 13th among the 500 fastest-growing technology companies in Europe, the Middle East and Africa.

It started with seeing an opportunity

When Serhat Gürcü graduated in 2005 and moved to Istanbul, there was no career in advertising waiting for him. He had no business network, no capital and no industry experience.

But he had noticed something important.

Big brands wanted to reach young consumers, yet struggled to understand their world. Traditional advertising was not keeping up with a youth culture that was changing fast.

Serhat saw a big opportunity in that gap, and founded Youth Republic.

Built to create real connections between young people and brands, Youth Republic became one of the pioneers of youth marketing in Türkiye. Over the ten years Serhat led it, the company grew to around 150 people and became one of the country's largest independent advertising agencies.

That first venture taught Serhat how to build not just a company, but a new market.

Years later, the same approach would be the start of a much bigger change.

A strong partnership built from different experience

While Serhat was carving out his own path as an entrepreneur, his sister Seden Gürcü was building a successful career in global advertising.

After completing her studies at the London School of Economics, Seden returned to Türkiye and joined Leo Burnett, one of the world's largest agency networks, where she rose to client services director. She later joined Youth Republic as vice president.

The two siblings brought complementary experience.

Serhat was an entrepreneur focused on building new business models and spotting opportunities early. Seden knew the needs of big brands, their corporate cultures and the workings of international marketing from the inside.

In 2015 they joined forces and founded YouthWorks.

YouthWorks brought three disciplines that advertising had long kept apart (data, media and creativity) under one roof.

The idea may not have been new, but the siblings put it at the centre of the business model. YouthWorks quickly became one of Türkiye's most talked-about independent agencies.

Across their careers, the world's biggest brands (Coca-Cola, Procter & Gamble, Unilever and Vodafone among them) have played a major part.

Through the companies they founded and ran, they have served more than 50 Fortune 500 companies.

That experience would become one of the biggest advantages of everything that followed.

Because they knew not only what big brands want, but how they make decisions, what problems they face and why they need to change.

An idea to change the future of advertising

One thought kept returning throughout their careers: systems that work in isolation can become smarter and more effective when they are brought together.

At Youth Republic they brought brands and young people together; at YouthWorks, data and creativity.

But advertising kept changing.

Digital channels multiplied, data scattered across platforms, and marketing teams had to work with ever more complex systems.

For Serhat and Seden, that complexity was a new problem to solve.

In 2022, before generative AI had reached the mainstream, the siblings began exploring its potential for the creative industries and using AI in the advertising process.

What interested them was not simply producing content faster. They imagined a new system in which human creativity, data and AI agents work together.

That idea led to a new venture in London.

Brave New World: from the title of a novel to a new creative future

The name they chose for their new venture said how ambitious the idea was: Brave New World.

It comes from the English writer Aldous Huxley's famous novel, published in 1932.

Huxley's Brave New World imagines a future in which technology transforms human life at its roots. It remains one of the best-known works of modern literature to question the power of technology and its effect on human life.

For Serhat and Seden, the name stood for the technological change we are living through.

By securing UK and European trade mark rights for Brave New World in advertising and marketing, they made the name the identity of their own creative technology venture.

Where Huxley's novel questioned the threats technology might pose to humanity, their venture set out after a different possibility: could technology carry the human imagination further?

Born from that thought, Brave New World developed a way of creative working unlike that of a traditional advertising agency.

The technology the company calls its agentic Creative Intelligence System brings AI agents together across consumer research, creative strategy and idea development.

The system helps creative teams explore more ideas, weigh different points of view and build stronger campaigns.

Used today by leading brands, this technology positions Brave New World beyond the traditional advertising agency, as a new-generation creative technology company.

For the siblings, AI is not a tool to replace human creativity. It is a new way of working that can push its limits further.

ADIN.AI: bringing marketing together in one intelligence

Serhat and Seden's vision for technology was not limited to creativity.

Working with global brands for years, they had watched another problem up close.

Big advertisers invest millions every year across different media channels. Yet planning, managing, measuring and optimising that investment happens in separate, disconnected systems.

Marketing teams had more data than ever, but turning it into meaningful decisions was getting harder.

To solve this, they launched ADIN.AI together with their fellow co-founders.

ADIN.AI is an AI platform built for marketing teams.

It brings together data from different advertising channels to help brands plan, manage, analyse and optimise their media investment.

The point is not to give marketing teams more tools, but to let them run different systems from one intelligent centre.

Used today by more than 50 brands in over 20 countries, ADIN.AI has become part of the marketing operations of major advertisers.

Its technology was built on the experience of a team that spent years solving the problems of the world's leading brands.

But what makes ADIN.AI's story remarkable is not only the technology. It is how fast that technology has grown.

A technology success story from Türkiye

ADIN.AI's rise caught the attention of leading institutions in technology and business.

In 2024 it ranked fourth in Fast Company Türkiye's list of the 50 Most Innovative Companies.

The most striking result came a year later.

In the Deloitte Technology Fast 50 Türkiye 2025 programme, ADIN.AI took first place with growth of 8,990%, named Türkiye's fastest-growing technology company.

The result showed not only the rapid growth of a young technology company, but that an AI platform built in Türkiye was starting to find its place in international markets.

In the Deloitte Technology Fast 500 EMEA 2025 ranking, the company also placed 13th among 500 technology companies across Europe, the Middle East and Africa.

Its 4,348% revenue growth in the EMEA ranking was another clear sign of ADIN.AI's performance on an international scale.

Its investors include the Artificial Intelligence Factory of İş Bankası, one of Türkiye's longest-established financial institutions.

Together, these milestones show that ADIN.AI is not just a promising idea, but a company with real customers, working technology and international growth.

Given that Serhat arrived in Istanbul in 2005 with no resources at all, these achievements hold a special place in the story.

The young entrepreneur who started his first company after spotting a communication gap between big brands and young people is now among the founders of a global company building AI to manage those same brands' marketing investment.

A shared vision

Serhat and Seden Gürcü's roughly fifteen years of working together have been recognised with hundreds of awards in Türkiye and internationally.

Serhat has been named to Fortune Türkiye's 40 Under 40 list five times. Seden is a Great British Entrepreneur Awards 2026 finalist (Equity-Backed Entrepreneur of the Year) and has been named to Fast Company's Female Founders 100 five years running.

But what runs through their story is more than awards or the size of the companies they built.

With every new venture, they focused on a problem the industry had not yet fully solved.

  • With Youth Republic, they created a new space in youth marketing.
  • With YouthWorks, they brought creativity, data and media together.
  • With Brave New World, they brought AI agents into human creativity.
  • With ADIN.AI, they brought separate marketing systems together in one intelligent platform.

Four different ventures, one shared idea.

Bringing disconnected worlds together to make possible what wasn't possible before.

From Istanbul to London, from services to technology

Serhat and Seden's story is not just about two successful advertising people going international.

It is the journey of two entrepreneurs who knew an industry from the inside for years, worked with the world's biggest brands, and finally decided to build their own technology for that industry's future.

Careers that began in Istanbul continue today with AI technology built in London and used in different countries.

In the past, they brought creative ideas and marketing services to the world's biggest brands.

Now they are building systems that could change how those brands work in the future.

And perhaps that is the most striking part of the journey.

Serhat and Seden Gürcü were never content to simply adapt to a changing world. At every major shift in their careers, they asked themselves the same question:

Why shouldn't we be the ones to build the next world?