Mario Racek, Developer in Prague, Czech Republic
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Mario Racek

Verified Expert  in Engineering

Quality Assurance Engineer and Developer

Prague, Czech Republic
Toptal Member Since
September 9, 2022

Mario is a quality assurance engineer with over six years of industry experience working for startups and corporate clients. He focuses on web, mobile, and automation testing, including cross-browser, iOS, Android, and Chrome application testing. In addition, Mario has experience in test and defect management, data preparation, and test execution. Mario prides himself on being diligent, adaptable, and goal-oriented and is eager to take on new challenges.


MySQL Workbench, Postman, Swagger, Chrome DevTools, GitLab, Java, Playwright...
Postman, Newman, GitHub, Sauce Labs,, Automated Testing, Xcode...
Cypress, TypeScript, GitLab, WebStorm, YouTrack, TestLodge, QA Automation...




Preferred Environment

MacOS, Slack, iOS, Android, Chrome, Jira, GitHub, Postman, Kibana

The most amazing...

...testing environment I've set up included tools, processes, a CI/CD pipeline, and a set of regression tests for the company's QA department.

Work Experience

Head of QA

2022 - 2024
  • Headed QA operations, ensuring smooth release deliveries through effective communication with the PO and PM.
  • Collaborated with the CTO and developers to resolve complex bugs and technical issues.
  • Maintained high standards of quality assurance across all testing processes.
  • Understand complex diagrams for new features from FE to BE.
Technologies: MySQL Workbench, Postman, Swagger, Chrome DevTools, GitLab, Java, Playwright, Zephyr, Figma, Lucidchart, Miro, Manual Software Testing, Web Applications, Testing Strategy

QA Engineer

2021 - 2023
  • Prioritized familiarizing myself with the Swift and Kotlin code to implement the software development kit (SDK).
  • Set up QA processes, tools, and workflows for the mobile SDK team.
  • Created smoke, regression, and feature scenarios for manual and automation testing.
  • Designed the automation workflow and created a proof of concept for the automation process using Sauce Labs and GitHub Actions for the CI/CD pipeline.
Technologies: Postman, Newman, GitHub, Sauce Labs,, Automated Testing, Xcode, Android Studio, Data Preparation, Manual Testing, Test Management, Test Case Execution, Defect Management, Mobile App Testing, Test Analysis, GitHub Actions, QA Testing, Quality Assurance (QA), Manual QA, QA Automation, Test Documentation, CI/CD Pipelines, Mobile, Testing, Manual Software Testing

Test Automation Engineer

2021 - 2021
  • Automated regression tests using Page Object Pattern.
  • Helped create the test automation strategy and approach.
  • Participated in code reviews for the automation team.
Technologies: Cypress, TypeScript, GitLab, WebStorm, YouTrack, TestLodge, QA Automation, Testing, Web App Testing, Manual Software Testing, Web Applications

Junior Test Automation Engineer

2021 - 2021
SmarTest Automation
  • Automated web-based online casino games for various browsers.
  • Fixed automation test cases bugs and reported new bugs in Jira.
  • Created new regression tests based on tasks from senior automation engineers.
Technologies: Selenium WebDriver, Java, Apache Maven, TestNG, QA Automation, Testing, Manual Software Testing

Senior Mobile Tester

2018 - 2021
Fortuna Entertainment Group
  • Tested native mobile applications for Android and iOS devices in five countries and discussed the whole testing process with the scrum master, project and product managers, and developers.
  • Handled the entire testing process, including the test requirements analysis, feature testing, regression testing, test cases, and test scenario creation, and took part in Scrum ceremonies like daily stand-ups, retrospectives, planning, and grooming.
  • Developed feature and regression automated tests using Appium and Java for iOS and Android devices and kept track of the GitLab repository and CI/CD pipeline updates.
Technologies: Charles Proxy, Jira, Confluence, Zephyr, Slack, Postman, Java, Cucumber, Appium, Bitbucket, Android, iOS, Test Analysis, Test Case Execution, Regression Testing, Test Automation, Manual Testing, Automated Testing, GitLab, Jenkins, Data Preparation, Defect Management, Mobile App Testing, IntelliJ IDEA, SQL, Quality Assurance (QA), Manual QA, QA Testing, QA Automation, Test Documentation, CI/CD Pipelines, Mobile, Testing, Manual Software Testing

IT Tester Senior | Team Leader

2017 - 2018
  • Mentored new team members and participated in interviewing potential candidates.
  • Reported on the test execution and test analysis progress of quarterly releases and allocated work to testers based on their availability.
  • Evaluated yearly goals completed by testers and set new goals based on their preferred career paths.
  • Attended weekly meetings with other department test leads and discussed work allocation, the test department, and any potential issues.
Technologies: Team Mentoring, Reporting, Workflow, Interviewing, Evaluation, Leadership, Test Documentation, Web App Testing, Manual Software Testing

IT Tester | Test Lead

2017 - 2017
  • Led a 4-person team testing a mobile banking application, assigned daily tasks, discussed issues, and allowed them to focus on testing by handling obstacles.
  • Reported critical bugs and daily test progress to test managers and attended meetings with the head of the project departments, where I presented the updates on these topics.
  • Participated in daily meetings with other test leads to discuss the progress and next steps.
Technologies: QA Leadership, Reporting, Communication, Workflow, Manual Testing, Mobile App Testing, Leadership, Manual QA, Quality Assurance (QA), QA Testing, Web App Testing, Manual Software Testing

IT Tester Junior

2016 - 2016
  • Tested the mobile banking application on Android and iOS devices using multiple mobile phones and tablets with different operating system versions.
  • Investigated and reported bugs using Jira and Charles, used the Android Studio for debugging, Logcat for searching through logs, and Xcode and the internal logging tool for the iOS platform debugging.
  • Created regression and feature scenarios for the entire application using HP ALM, with the help of requirement documents and technical and business analysis, while collaborating with a test analyst.
Technologies: Kibana, iOS, Android, Manual Testing, Data Preparation, Mobile App Testing, Test Case Execution, Defect Management, Charles Proxy, Jira, HP Application Lifecycle Management (ALM), Google Chrome, Firefox, Internet Explorer, Android Studio, Logcat, SQL, Website Testing, Quality Assurance (QA), Manual QA, Test Documentation, Testing, Web App Testing, Manual Software Testing, Web Applications

Web Developer

2014 - 2016
  • Created numerous landing pages for IBM's products using CSS and HTML templates.
  • Maintained existing web pages for IBM's products and discussed possible changes with production leads.
  • Contributed to other projects as part of the daily workload.
Technologies: CSS3, HTML5, JavaScript

Mobile Banking Application
Acted as a tester and test lead for a multichannel mobile banking application project that was part of an extensive redesign of the banking application's main front-end and back-end channels.

At the start of the project, I was the only tester on the team and created test cases, test scenarios, and smoke and regression tests. I tested the login and registration features, including going through extensive logs and collaborating with back-end and front-end developers.

As the project progressed, I was promoted to the test lead position, where I continued testing the application and led four application testers. I also met with managers and presented the testing progress, blockers, and critical bugs.

Setup of QA Processes at Smartlook

Set up manual testing processes and created the proof of concept for the mobile SDK team's automation testing. As the company's first QA engineer, I researched manual and automation testing tools and had meetings to discuss the environment setup, existing front-end and back-end processes, and how to introduce QA processes.

I chose the tools and designed the testing process workflow, covering how developers report and treat bugs and how to fit automated tests into the CI/CD pipeline. I also created over 70 test cases documenting SDK's functional aspects.
2011 - 2014

Bachelor's Degree in Applied Informatics

Comenius University - Bratislava, Slovakia


Appium – Mobile Testing (Android/iOS) from Scratch+Frameworks



Automated Web Testing – Selenium



Adobe Photoshop – Web and Applications Design



HTML5, CSS3, and News in Web Technologies



Newman, Selenium WebDriver, Playwright


IntelliJ IDEA, Slack, Jira, Charles Proxy, GitLab, Confluence, Zephyr, HP Application Lifecycle Management (ALM), Android Studio, Adobe Photoshop, Apache Maven, GitHub, Postman, Kibana, YouTrack, Cucumber, Bitbucket, Logcat, Jenkins, Xcode, WebStorm, TestLodge, MySQL Workbench, Figma, Lucidchart, Miro


Google Chrome, Firefox, Internet Explorer, iOS, Android, MacOS, Mobile


Java, HTML5, CSS3, JavaScript, TypeScript, SQL


Manual Testing, Agile, Testing, Automated Testing, Test Automation


Appium, Chrome, Selenium, XCUITest, Espresso, TestNG, Cypress, Swagger




Mobile App Testing, Data Preparation, Regression Testing, QA Testing, Quality Assurance (QA), Manual QA, Manual Software Testing, Test Analysis, Defect Management, QA Leadership, Test Case Execution, Reporting, Test Management, Leadership, QA Automation, Test Documentation, Web App Testing, Web Applications, ChromeDriver, Communication, Team Mentoring, Workflow, Interviewing, Evaluation, Sauce Labs,, GitHub Actions, Website Testing, CI/CD Pipelines, Complex Problem Solving, Analytical Thinking, Chrome DevTools, Testing Strategy

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