The Genius Story of Luis Von Ahn from inventing CAPTCHA to founding Duolingo.

Did you know that when you complete one of those really annoying “I am not a robot” tests that ask you to enter hard to read letters — you are actually helping to transcribe books — I know, clever.

Well clever isn’t really a big enough word for Luis Von Ahn, the literal genius behind those tests as well as Duolingo — the incredibly addictive language learning app with 80 million users and worth $9 billion.

I have always been fascinated and inspired by stories and experiences of other entrepreneurs and inventors. When I first started I had no idea what I was doing and by reading and studying successful entrepreneurs I was able to learn from their experiences .

Luis Von Ahn is a geek — in the best possible way. Maths professor, computer engineer, academic research and genius grant award winner.

Growing up in guatemala. His mother ran a sweet shop. Kids growing up with their own sweet shop might make you picture Augustus Gloop, but Luis was far more interested in the machines that made the candy than he was in the sweets themselves — spending his weekends taking the machines apart and putting them back together.

A maths prodigy, and early video game addict little did Luis know he was practising the skills that would be critical to his later ventures.

Luis moved to the united states and started a PHD in computer science. Early into the course he attended a free lecture given by a top executive at Yahoo — Yahoo basically ran the internet at the time. The executive described a challenge Yahoo had with people using programmes to create millions of free email accounts that they then used to send millions of spam emails.

Yahoo could not solve the problem.

Luis worked out that the key was to do something to distinguish between a real human going to Yahoo to set up an email account and a robot programme the same. At the time, computers were pretty bad at reading distorted letters, but humans could. So he created a little test that would generate an image of distorted letters and ask the human to enter them.

CAPTCHA was born.

Rather naively, Luis emailed Yahoo, telling them he had solved the problem and explaining the solution.

Yahoo said thanks, integrated the solution and their problem was gone. Luis received no money whatsoever.

Within weeks, CAPTCHA solutions were on all major websites — making it impossible for robots to abuse websites — and frustrating humans the world over.

Luis continued with his PHD and kept experimenting. He created an online game called ESP which showed you a picture and asked you to guess what words other people had typed for that same picture. What was happening behind the scenes here wasn’t a game at all, he was crowdsourcing image tags. When 2 or more people typed the same thing the system tagged that image. He sold ESP to Google, this time for real money.

In 2006 Luis received the MacArthur Fellowing award, which is basically a grant for being a genius. You don’t apply for it, you just get it. It’s a $500,000 prize for you to do whatever you want — just for being smart.

One downside to having invented CAPTCHA was living with the knowledge that you are wasting a lot of human time. Even when Luis wasn’t thinking about that he was quickly reminded by someone telling him how annoying it was.

Around the same time, Google had announced that they wanted to digitise all the worlds books. They were literally scanning in millions of books in dozens of languages. The problem was that computers could not recognise about 30% of the letters being scanned in — due to distorted images. Luis came across this problem and put 2 and 2 together (told you he was a maths wizard) RE-CAPTCHA was born.

Now each time you had to prove that you weren’t a robot, rather than random letters with no meaning, you were actually seeing letters scanned in from books — when 10 or more people provided the same answer for the same image it went into a database allowing them to consider that letter to be accurately transcribed.

Luis got fast growing websites like Facebook to use it, as well as established brands like the New York Times.

Google approached Luis and acquired RE-CAPTCHA — the amount isn’t known, but is said to be more than $10 million.

While working at Google to integrate RE-CAPTCHA, Luis meets another programmer, Severin Hacker and they start working together.

Neither Luis nor Severin were native English speakers, but the ability to speak English had changed their lives. So they decided to focus on tools that would help other people learn languages.

They started with a translation service, based on the CAPTCHA model that was designed to help media companies translate their content into different languages by crowdsourcing translation from people who wanted to learn. They gave free language lessons in exchange for translation.

The problem was they realised they were building a translation company, not an education company.

At the same time, smartphone sales were booming and with them the emergence of the App.

Luis and his team designed the Duolingo app, they dropped the translation services and focused on building a free tool to help people learn a language with nothing but their phone.

Their platform grew really really fast, with millions of users. The main problem now was they had no revenue stream. Luis raised millions from venture capital, but needed to work out a way for the business to make money.

They were determined keep access to language education free. So, they implemented a model similar to Spotify. A free version with ads or a premium, paid for subscription version without adverts.

These monetization models combined with their massive and fast growing userbase gave Luis a very successful business.

They wrapped all this in a beautifully designed and very clever gamification UI. Gracefully promoting users to get more lives and therefore more content on any given day with the upgraded version.

Their exceptional use of play in design does not end there. Everything from notifications, social integration and app navigation is crafted in a way to make learning fun, addictive and memorable.

Today, Duolingo has more than 83 million active users and is still growing at a rate of almost 50% per year. Over 3 million of those users have a streak greater than 365 days, meaning they have used the app every day for more than a year.

The app is worth more than $9billion and Luis himself is said to have a fortune of $50 million.

What can we learn from Luis and his story?

Well for me the top takeaway is to put yourself into situations in life where you can be struck by serendipity. Luis wouldn’t have created Capture if he didn’t go to that free lecture, he wouldn’t have started Duolingo if he haven’t met Severin.

Secondly, I think Luis story is one for keeping your eyes open for problems and solutions — recapture happened because he was holding a problem in his head and was open to solutions when they presented themselves.

If you want to discover opportunities then you have to put yourself in places where opportunities are likely to be. Conferences, courses, meet people, talk to people — increase your chance of benign struck with inspiration.

Luis is a true trailblazer. He has been involved in some of the less sexy but equally important building blocks of the internet.

I am certainly inspired by Luis and his story — I hope you are too!