Code katas, a term first coined by Pragmatic Programmer Dave Thomas, are small programming exercises geared to hone a specific programming skill. Traditionally, they tend to be algorithmic like parsing or visiting graphs but could as well aim to improve understanding of particular programming paradigms, like functional or object oriented, or a specific language. Also, as remarkably pointed out by Matteo, katas can be crafted to master a certain technology like web or database. While, as you may guess, Coding Dojos are sites, groups or communities which propose and maintain collections of katas hopefully with solutions and reviews.

So, how do you practice? I suggest you solve a kata, review your work, compare it to other solutions, share your code with others and discuss it. Then solve it again trying to take a different path, balance pros and cons, then solve it again and again, until you feel you internalized the essence of the problem. Finally, you can move to another kata. If it feels like a lot of work, then you got it right. No question mastership requires time and effort but, then again, masters are those destined for greatness.

Resources

• Katacasts
• 21 Code Katas by Dave Thomas
• Lots of Code Quizzes with Ruby Solutions
• Matteo Vaccari’s Technological Katas
• Coding Dojo Code Katas
• Corey Haines Video Solution in Ruby of String Template
• Uncle Bob Code Katas (search “kata”, ie bowling kata)
• Micah Martin on Code Katas and Video Solution in Ruby of Langton’s Ant
• Micah Martin’s BattleShip Tournament
• Google Code Jam
• Jeff Atwood on Code Katas
• Steve Yegge on Code Katas
  
• Peter Norvig on Deep Practice

Actually this has been something known to humanity for at least a century and it’s best explained by this quote from Thomas Edison:

Genius is 1% inspiration and 99% perspiration

The point is that becoming great at something is largely a matter of the amount and quality of practice one does. While God given talent can only boost this process, but it’s by no means the most influential factor.

About the amount of practice, there’s the old “Ten Years Rule” and a more refined study by Anders Ericsson who sets in 10000 hours of committed practice the time taken to achieve expert level. From the Pomodoro Technique, we know one can do about 5 hours/day of efficient work (10 pomodoros). That means 5 years and a half, 5 hours every day of hard work could be a good guess to the question “How long does it take?”.

About the quality of practice, the book calls the good one “deep practice”

working on technique, seeking constant critical feedback and focusing ruthlessly on shoring up weaknesses

So deep practice has a pretty simple recipe:

• practice just beyond your current ability
• focus on errors
• fix them
• repeat

Basically, it’s tenacious, steady continuous improvement, so it’s not surprising Kaizen is mentioned in the book.

In the end, we are left with two news: one bad, one awesome. The bad one is if you fail to reach master level in a discipline you care of, there’s no one to blame but yourself. Sadly, you got to take responsibility even for that. But the awesome news is you can really become what you want be. Just keep working.

Let’s close with this sweet advice from great italian poet Giovanni Papini

Chiunque, purché sappia chiaramente cosa vuol divenire e non perda un solo secondo della sua vita, può issarsi al livello di coloro che dettano le leggi alle cose e che creano vite più degne. (Da “Diventar Genio” – 1912)

and my rough translation

Anyone, as long as he clearly knows what he wants to become and doesn’t waste a single second of his life, can raise himself to the level of those who lay down the law of things and create more worthy lives (From “Becoming Genius” – 1912)