Oleg Andreev



Software designer with focus on user experience and security.

You may start with my selection of articles on Bitcoin.

Переводы некоторых статей на русский.


Product architect at Chain.

Author of Gitbox version control app.

Author of CoreBitcoin, a Bitcoin toolkit for Objective-C.

Author of BTCRuby, a Bitcoin toolkit for Ruby.

Former lead dev of FunGolf GPS, the best golfer's personal assistant.


I am happy to give you an interview or provide you with a consultation.
I am very interested in innovative ways to secure property and personal interactions: all the way from cryptography to user interfaces. I am not interested in trading, mining or building exchanges.

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October 2

How to backup bitcoins on Mac OS X

Bitcoin-qt app stores private keys in ~/Library/Application Support/Bitcoin/wallet.dat

  1. Make sure you encrypt your wallet (Settings -> Encrypt Wallet). Write down the password on a secret piece of paper ;-)

  2. Make sure you back it up properly. By default, Time Machine should backup entire Application Support, but this would exhaust your backup disk quickly because it will continuously back up 3 GB blockchain. I recommend excluding every Bitcoin/* file except wallet.dat (see the screenshot).

Remember: if you lose wallet.dat, your money is gone forever.