Karl Cordes

Email: karl@cordes.com.au

Phone: +61415397713

About

I am a software developer and systems administrator who is passionate about the web, and I love building quality products to make it a better place.

I take ownership of the projects that I work on, and I deliver reliable and scalable solutions.

Skills

Languages

  • Bash
  • C
  • CSS
  • Go
  • HTML
  • Java
  • Javascript
  • PHP
  • Perl
  • Python
  • Ruby

Frameworks

  • Flask
  • Ruby on Rails
  • Sinatra

Operating Systems

  • Linux (Debian/Ubuntu, RHEL/CentOS)
  • Mac OS X
  • Windows

Daemons, service providers and favourite tools

  • Apache
  • AWS
  • Ansible
  • Caddy
  • Docker
  • Git
  • GNU Emacs (currently)
  • MySQL
  • nginx
  • PostgreSQL
  • rsync
  • SQLite
  • Terraform
  • vim (formerly)

Education

University of New South Wales

Bachelor of Science in Computer Science

2007 - 2010

Experience

Atlassian

Senior Systems Engineer

2020 - Present
  • PostgreSQL (RDS) database administration for Mailtracker, an email events tracking system that handles 1 billion+ events per month (table partitioning, correct indexes, query optimisation)
  • Built features to detect spammers abusing Atlassian services to send email
  • Worked with Support Engineers to investigate unusual customer email problems
  • Wrote documentation and tools to help Support Engineers to self-service customer problems
  • Built features for Go services running on the AWS Serverless stack

Atlassian

Systems Engineer

2018 - 2020
  • Built and ran a centralised outbound email service for Atlassian cloud products
  • Email troubleshooting for support engineers and customers
  • Designed and built Mailtracker service to store email events in PostgreSQL for troubleshooting and analysis. Handles 1 billion+ email events per month

Atlassian

Site Reliability Engineer

May 2015 - 2018
  • Worked a 24x7 rotating on-call roster. Managed customer impacting incidents.
  • Built a service to reduce the blast-radius of bugs hitting production using canary hosts
  • Wrote tooling in Python and Go to automate repetitive operational work
  • Built tools using JIRA and Confluence APIs to generate weekly reports
  • Built tools help migrate customers from bare metal infrastructure to AWS

Yahoo7

Service Engineer

April 2014 - April 2015
  • Managed production code releases. Worked with developers and product owners to ensure code changes were released on schedule without impacting service availability
  • Used configuration management tools to provision new testing and production infrastructure
  • Worked a rotating 24x7 on-call pager duty. Responded to alerts and incidents to resolve them quickly
  • Applied critical security fixes to hundreds of production servers. Fixed Heartbleed, Ghost and Shellshock vulnerabilities
  • Used Jenkins-based build infrastructure to help achieve continuous delivery

Tectonic Digital

Web Developer

December 2011 - February 2014
  • Built a wide variety of web applications for clients using PHP (Laravel, WordPress), Javascript (AngularJS), and Ruby on Rails
  • Designed and built a custom PHP + MySQL application hosting infrastructure on Amazon Web Services OpsWorks using Chef
  • Systems administration of web hosting infrastructure running on on AWS
  • Built a mobile web application for Google using AngularJS and Laravel

CMC Technologies

Web Application Developer & Linux Systems Administrator

2007-2011
  • Designed and built a custom CRM, document generation, and email processing web application to streamline the sales process
  • Procured and administered Linux web and email servers