Hi, I’m Calle! 👋

I’m a programmer based in Stockholm, Sweden. Below, you’ll find some blog posts I’ve written. There’s also a page with talks I’ve given. Read more about me or say hi!

🐦 👨‍💻

• HyperLogLogs in Redis

  August 1, 2016 · Published on Giant Robots Smashing Into Other Giant Robots

  Learn what a HyperLogLog is and how you can use it to count billions of unique things.

• My First Product Design Sprint

  July 7, 2016 · Published on Giant Robots Smashing Into Other Giant Robots

  Product Design Sprints are great for validating ideas and concepts, and developers can both learn and add a lot to them.

• Postgres Index Types

  April 21, 2016 · Published on Giant Robots Smashing Into Other Giant Robots

  Improve query performance by using the right index type.

• Ruby’s ARGF

  October 13, 2015 · Published on Giant Robots Smashing Into Other Giant Robots

  How to write well-behaved data-processing Unix utilities in Ruby.

• The Four Stages of Compiling a C Program

  August 7, 2015

  Knowing how compilation works can be very helpful both when writing code and when debugging.

• Announcing pick

  March 10, 2015 · Published on Giant Robots Smashing Into Other Giant Robots

  Fuzzy select anything.

• Flags, Bitmasks, and Unix File System Permissions in Ruby

  February 16, 2015

  In a previous post, I described how Ruby’s bitwise operators work. In this post, I’ll provide some ways to use them.

• Man Pages For Your RubyGems

  November 1, 2014 · Published on Giant Robots Smashing Into Other Giant Robots

  An experiment on using man pages for Ruby and Ruby gem documentation.

• Intent to Add

  August 9, 2014 · Published on Giant Robots Smashing Into Other Giant Robots

  How to use git add --patch for untracked files.

• Running WeeChat on a Server for IRC Backlogs

  August 4, 2014 · Published on Giant Robots Smashing Into Other Giant Robots

  Don’t miss anything that happens in the channels you are connected to, even when you’re offline.

• WeeChat for Slack’s IRC Gateway

  August 1, 2014 · Published on Giant Robots Smashing Into Other Giant Robots

  Learn how to install, configure, and use the text based IRC client WeeChat with Slack’s IRC gateway.

• Setting Up a Basic Linux Server

  June 15, 2014

  In this guide, I’ll show you how to set up and configure a basic Linux server in the DigitalOcean cloud running Debian 7 Wheezy.

• Ruby’s Bitwise Operators

  February 6, 2014

  Working in a high-level language like Ruby, it’s not common to find oneself in need of bitwise operators. Knowing how they work might nevertheless be both valuable and interesting.

• Splatting Regex Matches

  February 1, 2014

  Learn how to use Ruby’s splat operator when extracting data from strings and find out how it all works under the hood.

• Hash#fetch

  January 25, 2014

  After discovering the versatility of Ruby’s Hash#fetch method while watching one of Avdi Grimm’s excellent Ruby Tapas screencasts, I’ve found myself using it more and more. In this post I’ll share what I’ve learnt.