Karlo Smid, Developer in Zagreb, Croatia
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Karlo Smid

Verified Expert  in Engineering

Quality Assurance Developer

Zagreb, Croatia
Toptal Member Since
May 14, 2013

Karlo is a senior test engineer with skills in test automation, team leadership, and documentation. As a software tester, he likes to break stuff that others think works. As a team leader, he has proven abilities allowing him to build teams from scratch and streamline the QA process to perfection.


Ruby Page Object, RSpec, Ruby, Selenium WebDriver, Watir WebDriver, Cucumber
Watir WebDriver, Ruby, Ruby on Rails (RoR)
Ericsson Nikola Tesla
Cucumber, Appium, Android




Preferred Environment

Subversion (SVN), GitHub, Ubuntu, Linux, MacOS

The most amazing...

...thing I've built is an enhanced existing virtual agent with a natural head movement algorithm. I won a GALA 2006 award for it.

Work Experience

QA Lead Engineer

2013 - PRESENT
  • Created a modular and reusable test suite for a REST API endpoint in Ruby's httpclient and rspec libraries.
  • Created a modular and reusable MS SQL database ETL test suite in Ruby's rspec library.
  • Created a reusable and modular browser automation test suite in Cucumber, PageObject, Watir WebDriver, Selenium WebDriver, and Ruby.
  • Configured a headless browser test suite run on Jenkins in a Linux environment.
  • Created a load testing test suite in Grinder with a Jython load testing framework.
  • Handled security testing of all web application layers.
  • Built a Docker environment for running Ruby regression API tests on an OS that supports Docker.
Technologies: Ruby Page Object, RSpec, Ruby, Selenium WebDriver, Watir WebDriver, Cucumber

Security and Software Tester

2012 - PRESENT
  • Handled security penetration testing using OWASP ZAP.
  • Conducted security audits of web application infrastructure.
  • Analyzed security advisories regarding a web application platform.
  • Created an automated web testing framework in Ruby, Watir WebDriver, Sauce Labs, modern.IE, and CloudBees CI.
  • Provided security audits for source code written in Ruby on Rails, Ember, and React.
Technologies: Watir WebDriver, Ruby, Ruby on Rails (RoR)

Mobile QA Engineer

2015 - 2019
Ericsson Nikola Tesla
  • Handled exploratory testing of an Android application.
  • Created test cases in Cucumber.
  • Created a test framework in the Appium Ruby library.
  • Ran regression tests.
  • Gave effective and clear reporting of issues found in SourceForge.
  • Wrote a tool in elixir that diffs a large number of files.
Technologies: Cucumber, Appium, Android

QA Lead

2013 - 2013
  • Created browser automation scripts.
  • Created a test and development virtual machine based on CentOS using Vagrant and VirtualBox.
  • Handled PHP code analysis, looking for performance bottleneck and security issues.
  • Handled Web Service API testing using RSpec and Ruby.
Technologies: Watir WebDriver, Page Object Model (POM), Cucumber, PHP, Ruby

Test Lead

2001 - 2013
Ericsson Nikola Tesla
  • Created a regression testing framework in Jython for testing web services.
  • Created a load testing framework based on the Grinder Java framework.
  • Integrated it in a CI environment based on Jenkins and Maven.
  • Prepared a test plan.
  • Created test case designs based on requirements and system exploration.
Technologies: Java, Jython, Python

Virtual Agent | Simulation of a Television Speaker with Natural Face Gestures

My master's thesis, submitted in November of 2004.

Coherence Contributor

A full-featured, configurable authentication system for Phoenix.

Blitzy | Distributed Load Test Tool Written in Elixir

A not so simple HTTP load tester in Elixir.
2000 - 2004

Master's of Science Degree in Computer Engineering

Faculty of Electrical Engineering and Computing - Zagreb, Croatia

1992 - 1997

Master's Degree in Computer Engineering

Faculty of Electrical Engineering and Computing - Zagreb, Croatia


Black Box Software Testing Test Design

Association for software testing AST


Black Box Software Testing Bug Advocacy

Association for software testing AST


Black Box Software Testing Foundations

Association for software testing AST


Requests, Watir WebDriver, Selenium WebDriver, Sikuli, Ruby Page Object


Jenkins, Cucumber, RSpec, Bitbucket, Trello, GitHub, Git, Jira, Subversion (SVN)


Grinder, Zope, Appium, Factory Girl, Capybara, Ruby on Rails (RoR), Bootstrap, Phoenix


Java, Python, Ruby, Jython, PHP, JavaScript, Elixir


Test-driven Development (TDD), Unit Testing, ETL, REST, Load Testing, Object-oriented Programming (OOP), Page Object Model (POM), Agile Software Development

Industry Expertise



MacOS, Docker, Linux RHEL/CentOS, Windows, Debian Linux, Linux, Ubuntu, iOS, Android


PostgreSQL, MySQL, Microsoft SQL Server, IBM Informix Dynamic Server


Selenium PageFactory, Selenium Page Object, UI Testing, Strategy, Security, System Security Developer, Agile Software Testing

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