Approximate string matching cheat sheet

  1. Levenshtein distance : if the pattern is coil, foil differs by one substitution, coils by one insertion, oil by one deletion, and foal by two substitutions.
  2. Damerau–Levenshtein distance : Like Levenshtein but including transpositions among its allowable operations.
  3. Jaro–Winkler distance : designed and best suited for short strings such as person names.
  4. Smith–Waterman algorithm : performs local sequence alignment for determining similar regions between two strings, instead of looking at the total sequence.
  5. Needleman–Wunsch algorithm : divides a large sequence into a series of smaller problems and uses the solutions to the smaller problems to reconstruct a solution to the larger problem.
  6. Soundex : a phonetic algorithm for indexing names by sound, as pronounced in English.
  7. Metaphone : improves on Soundex by using variations and inconsistencies in English spelling and pronunciation.

A note to designers


  • Your job is to make things simpler, not cooler.
  • Restrain the product people from adding unnecessary features.
  • Save time for the engineering team, not make their lives harder.
  • Make sure that form follows function.

Forgive the early adopter

This is a letter to my friends and my colleagues.
I'm truly asking your forgiveness.
Forgive me for switching between messaging apps every few weeks.
Forgive me for forcing you to use my unfinished apps and services.
Forgive me for being mad at you when you buy the "wrong" phone, laptop or TV set.
Forgive the early adopter in me :-)

I really appreciate the fact that you're willing to go through all the beta phases and stick with it.
Your devotion will not be overlooked when our robot overlords take over us and appoint me as one of their liaisons.

Stop Complexity Insanity

Whatever you're doing, stop, breath, and listen to these folks:


  • Isaac Newton - "Nature is pleased with simplicity. And nature is no dummy"
  • Leonardo da Vinci - "Simplicity is the ultimate sophistication"
  • Antoine de Saint ExupĂ©ry - "Perfection is attained, not when there is nothing more to add, but when there is nothing more to take away."
  • 1 Corinthians 14:33 - For God is not a God of confusion but of peace. As in all the churches of the saints.
  • Bruce Lee - "It is not a daily increase, but a daily decrease. Hack away at the inessentials."
  • Oded H. Breiner - "Remove to Improve."

Apprenticeship-based education system


  • Each person will be allowed to choose his "master" and be his apprentice (e.g. a high school student can choose an experienced software developer as a "master").
  • In exchange for education, the master will get cheap labour (e.g. manual QA, or even personal help like cleaning).
  • Down to this point, it is very similar to the apprenticeship model that was common in the later Middle Ages and came to be supervised by craft guilds and town governments.
  • Here's the difference: back then, a master had high motivation to make his apprentice a good craftsman because he would often get him to work for him later on. Today, this model is rare because of the wide volatility in workplaces, and because of big companies.
  • So as an extra incentive, masters should get a cut of their apprentice's wage for a few years after the apprenticeship is over, but only if a certain wage level is achieved.
  • Benefits
    • Cheaper education to be paid by students in the future and only if their education was successful.
    • Higher quality education achieved by one-on-one sessions.
  • Dangers
    • Misuse of students by charlatans.
    • Hard to measure quality of teachers (masters).
  • Solutions to dangers
    • A rating system measured by the amount of money transferred from graduates to masters.
    • The more money that is transferred, the better was the education because the apprentice earns more.

Android wear SDK impressions

Android wear is extremely tied to intents and notifications.

Everything is managed using NotificationCompat API. If an app has standard notifications they will appear in the watch, and all the buttons in the notification will be available in the watch.

Everything in the watch has to be pro-active, besides apps that can register to a closed set of voice intents.

It has a few of interesting tweaks to notifications:
1. You can add a button to a notification that sends voice2text into the app.
2. You can stack multiple notifications.
3. Notifications can have pages for added data.
4. Notifications can have an image background.