Dimitrios is available for hire
Hire DimitriosDimitrios Karavias
Verified Expert in Engineering
Quality Assurance Developer
London, United Kingdom
Toptal member since March 10, 2022
Bio
Dimitris has worked with Google, BBC, Vodafone, and Duolingo. He has cut regression cycles from a week to a day with automation, increased team productivity by 25% with BDD, and unblocked stalled releases. He's an experienced QA automation architect who helps companies de-risk AI adoption, accelerate software delivery, and build efficient teams. Dimitris received his Bachelor's in Artificial Intelligence and Software Engineering at the University of Edinburgh, one of Europe's leading AI schools.
Portfolio
Restep (Self-funded Project)
Angular, Chrome Extensions, Java, SQL, Microsoft Azure, Notion, Postman, Docker...
Cherrington Media, LLC
Flowise, LangChain, Large Language Models (LLMs), Multistage LLM Chains...
Micrima Limited
Quality Assurance (QA), Manual Testing, Manual Software Testing, Test Reporting...
Experience
- Selenium WebDriver - 9 years
- Java - 9 years
- Page Object Model (POM) - 9 years
- Behavior-driven Development (BDD) - 9 years
- Mentorship - 9 years
- Automated Testing - 9 years
- REST APIs - 7 years
- Technical Hiring - 6 years
Preferred Environment
Windows, MacOS, Linux, Web Applications, Java, JetBrains IDE
The most amazing...
...thing I've introduced behavior-driven development to a company. In three months, we reduced bugs by 25% and developed stakeholder-friendly automated tests.
Work Experience
Founder
2020 - PRESENT
Restep (Self-funded Project)
- Worked on an educational Chrome extension. Focused on the product roadmap and delegating hands-on work.
- Managed a small team of contractors consisting of front-end and back-end developers and designers to build our MVP.
- Tested across our stack, from the Angular UI to the Java back-end and SQL database.
- Handled the team's task management and knowledge base.
Technologies: Angular, Chrome Extensions, Java, SQL, Microsoft Azure, Notion, Postman, Docker, Technical Hiring, Agile Project Management, Management, Financial Management, Mentorship, Team Mentoring, Team Leadership, Remote Team Leadership, API Testing, REST APIs, REST, Manual QA, Manual Testing, Manual Software Testing, Exploratory Testing, JavaScript, Selenium, Website QA, QA Testing, Software QA, Software Testing, Performance Testing, Apache JMeter, Continuous Delivery (CD), Continuous Integration (CI), CI/CD Pipelines, Build Pipelines, Docker Compose, APIs, Testing, UI Testing, Quality Assurance (QA), SDET, Software Development, Release Management, Test Planning, Load Testing, Functional Testing, Agile Software Testing, GitHub, E2E Testing, Delivery Management, Azure, Test Management, Agile, Git, Test Documentation, eCommerce, Azure DevOps, Software Release Management, Leadership, GitHub Actions, System Requirements, QA Leadership, Automation Tools, Software Testing Lifecycle (STLC), Object-oriented Programming (OOP), Automation, REST Assured, TypeScript, Testing Strategy, Team Management, UX Testing, React, Scrum, Visual Studio, DevOps, JSON, Test Data, LangChain, Playwright, Node.js, Cypress, Web Applications, Startups, Test Cases
QA Architect
2024 - 2025
Cherrington Media, LLC
- Created a comprehensive test plan for UI, API, and AI testing.
- Implemented end-to-end Playwright tests, running on GitHub Actions. The tests are reusable for acceptance, regression, and smoke testing.
- Set up Automated LLM Output validation using LangSmith.
- Signed off all tasks and performed manual exploratory testing for a client MVP.
- Worked with developers and the product team to implement structured error handling (personal initiative, not in the original set of responsibilities).
Technologies: Flowise, LangChain, Large Language Models (LLMs), Multistage LLM Chains, LangSmith, Quality Assurance (QA), QA Automation, API Testing, Testsigma, Jest, Playwright, GitHub, GitHub Actions, Laravel, Artificial Intelligence (AI), Web Applications, Startups, Test Cases
Quality Assurance/Testing Expert
2024 - 2024
Micrima Limited
- Created test plans to get regulatory approval for a new cancer detection device.
- Onboarded and handed them over to the client's permanent QA engineer.
- Completed test plans using simulators when hardware was not available for testing.
Technologies: Quality Assurance (QA), Manual Testing, Manual Software Testing, Test Reporting, SQL, CI/CD Pipelines, DevOps, Azure DevOps, Visual Studio, Startups, Test Cases
QA Automation Architect
2023 - 2023
Berry Appleman & Leiden
- Assessed the team performance from a QA and release management perspective.
- Reduced the test run duration from hours to minutes. The test data set up was optimized, and excessive, fragile checks were removed, improving performance and maintainability.
- Provided the roadmap to org-wide BDD rollout. This is expected to speed up releases from weeks to days and reduce duplicated test efforts. Provided additional guidance for each department (QA, development, product, and management).
- Onboarded Toptal's QA engineers and led refactoring of the client's test suite. The goal was to reuse and gradually improve the current framework instead of starting from scratch.
Technologies: QA Automation, Quality Assurance (QA), Test Automation, Behavior-driven Development (BDD), Java, Azure, Azure DevOps, Team Leadership, Remote Team Leadership, Cross-functional Team Leadership, Web App Testing, Automation, Advisory, REST Assured, Non-functional Testing, Microservices, Testing Strategy, Team Management, Scrum, Test Reporting, DevOps, JSON, PostgreSQL, Test Data, REST APIs, Selenium, Web Applications, Cucumber, Unit Testing, Test Cases
QA Lead
2022 - 2022
Animo Services LLC
- Aligned in-house and third-party QA teams and led them toward a unified QA strategy.
- Oversaw EU-based team, and represented team to US senior stakeholders.
- Performed testing on the web app and coordinated with mobile teams.
Technologies: Quality Assurance (QA), Mobile App Testing, Python, Manual Testing, Azure, Manual QA, Manual Software Testing, Website Testing, Test Management, TestRail, QA Testing, Offshore Team Management, Automation Tools, Software Testing Lifecycle (STLC), Object-oriented Programming (OOP), Audits, Web App Testing, Automation, Advisory, Non-functional Testing, Microservices, Testing Strategy, Team Management, Test Reporting, JSON, Test Data, REST APIs, Web Applications, Startups, Test Cases
Freelance QA Automation Engineer
2020 - 2020
Duolingo
- Set up Duolingo's Android instrumentation tests using Espresso with Kotlin.
- Collaborated with the developers and QAs to migrate automated tests from third party to native technology stack.
- Researched, trialed, and set up a cloud-based mobile device farm.
- Raised issues while debugging the app which where resolved with the team, reducing app launch time by 50%.
Technologies: Android, Espresso, Kotlin, Automated Testing, Automated UI Testing, QA Automation, Mobile Device QA Automation, APIs, Testing, Quality Assurance (QA), Manual QA, Manual Testing, Postman, Python, SDET, Mobile Apps, Software Development, QA Testing, Functional Testing, GitHub, E2E Testing, Test Automation Frameworks, CI/CD Pipelines, Mobile App Testing, Test Management, Android Studio, Git, Test Documentation, Mobile Applications, Mobile, Mobile UI, Automation Tools, Software Testing Lifecycle (STLC), Object-oriented Programming (OOP), Automation, Android Testing, Microservices, Testing Strategy, UX Testing, Test Reporting, JSON, Test Data, Performance Optimization, Test Cases
Freelance QA Automation Engineer
2019 - 2020
Novoda
- Helped an agency with several household brands on upcoming projects.
- Tested Chromecast with Google TV prototypes as part of a joint effort between Google and BBC.
- Tested blu vaping devices, especially their end-to-end firmware OTA update process and their accompanying Android app.
- Set up automated UI testing on iOS for Vodafone's new R&D lab in Berlin.
- Tested Vodafone Smart connected devices and mobile app.
Technologies: Android, iOS, Kotlin, Swift, Java, Android TV, Internet of Things (IoT), AOSP, Espresso, XCUITest, Connected Devices, Automated Testing, Automated UI Testing, Mobile Device QA Automation, QA Testing, Manual QA, Test Automation, Test Automation Frameworks, cURL Command Line Tool, APIs, Testing, Quality Assurance (QA), Manual Testing, SDET, Mobile Apps, Software Development, Jira, Test Planning, Hardware Testing, Functional Testing, Agile Software Testing, Jenkins, Confluence, GitHub, E2E Testing, CI/CD Pipelines, Mobile App Testing, Manual Software Testing, Test Management, Xcode, Android Studio, Agile, Git, Test Documentation, Mobile Applications, Mobile, Mobile UI, QA Leadership, GitLab, Automation Tools, Firmware, Firmware over the Air (FOTA), Software Testing Lifecycle (STLC), Object-oriented Programming (OOP), Audits, Over-the-top Content (OTT), Automation, Android Testing, Advisory, REST Assured, TestNG, Video Streaming, TV, TV Broadcasting, Broadcasting, Testing Strategy, UX Testing, React, Scrum, Jest, Test Reporting, Visual Studio, DevOps, JSON, PostgreSQL, Test Data, Accessibility, REST APIs, Node.js, Performance Optimization, Cypress, Web Applications, XCUnit, Unit Testing, Test Cases
Client Services Technical Manager
2019 - 2019
Novoda
- Managed multiple projects with a budget range of £20,000–60,000 per month.
- Acted as the main point of contact within cross-functional teams to ensure the ongoing success of our clients' projects.
- Started freelancing and working as an independent QA engineer.
Technologies: Android, iOS, Account Management, Mobile Apps, Software Development, Jira, Agile, Leadership, System Requirements, Mobile Applications, Mobile, Mobile UI, QA Leadership, Software Testing Lifecycle (STLC), Audits, Advisory, Video Streaming, Testing Strategy, Team Management, React, Scrum, Startups
QA Engineer
2017 - 2019
Novoda
- Tested connected devices for a car insurance startup that used the device readings to rate customers' driving and offer better premiums to safe drivers. Created custom test rigs to simulate events like rapid acceleration, cornering, etc.
- Helped clients build and train testing teams on-site and overseas, improved their testing practices, and introduced a quality-first mindset across the board.
- Created Android and iOS testing suites using native testing frameworks such as Espresso and XCUITest, page objects, and testing robots. Reduced regression testing time from days to hours in multiple projects.
- Introduced BDD to clients, which reduced the number of bugs per sprint by 25% in three months.
- Integrated automated testing suites into CI pipelines.
- Introduced the clients' teams to behavior-driven development and improved their internal communication.
Technologies: Android, iOS, Espresso, Swift, Behavior-driven Development (BDD), Cucumber, Cucumberish, Jenkins, XCUITest, Page Object Model (POM), Mockito, Gherkin, Kotlin, Java, Charles Proxy, Postman, Docker, Technical Hiring, Technical Documentation, API Testing, Automated Testing, Automated UI Testing, Mobile App Testing, Manual QA, Manual Testing, Manual Software Testing, Selenium, QA Testing, QA Automation, Quality Assurance (QA), Continuous Delivery (CD), Continuous Integration (CI), CI/CD Pipelines, Docker Compose, cURL Command Line Tool, APIs, Testing, SQL, SDET, Software Development, Jira, Test Planning, Augmented Reality (AR), Hardware Testing, Functional Testing, ARKit, Agile Software Testing, Confluence, GitHub, E2E Testing, Test Automation Frameworks, Delivery Management, Test Management, Xcode, Android Studio, Agile, TestRail, Git, Test Documentation, Integration Testing, Leadership, System Requirements, QA Leadership, GitLab, Automation Tools, Firmware, Firmware over the Air (FOTA), Software Testing Lifecycle (STLC), Object-oriented Programming (OOP), GitLab CI/CD, Over-the-top Content (OTT), Automation, Android Testing, Advisory, Video Streaming, Testing Strategy, UX Testing, Scrum, Test-driven Development (TDD), Test Reporting, DevOps, JSON, PostgreSQL, Test Data, Accessibility, REST APIs, Performance Optimization, XCUnit, Unit Testing, Test Cases
Test Developer
2014 - 2017
Capita Employee Benefits
- Implemented UI tests using Selenium, Java, and the Page Object Model.
- Collaborated with the development teams to monitor their unit test coverage using SonarQube, which increased the coverage from 20% to 80% in critical areas.
- Tested new features manually, including inspecting all levels from the UI through the server to the database.
- Deployed on Linux-based environments and monitored performance.
- Interviewed candidates for QA positions, including junior, mid-level, and senior. Trained new joiners on test automation.
- Joined the release manager schedule, coordinated releases to production, and made the final go or no-go decision when problems arose.
Technologies: Selenium WebDriver, Java, REST APIs, Mockito, WireMock, SonarQube, JUnit, Cucumber, Behavior-driven Development (BDD), Linux, Appium, Docker, Oracle SQL, MongoDB, Page Object Model (POM), Apache JMeter, Apache Tomcat, Technical Hiring, Mentorship, API Testing, Automated Testing, Automated UI Testing, BrowserStack, Manual QA, Manual Testing, Manual Software Testing, Regression Testing, JavaScript, Selenium, QA Automation, Website Testing, Test Automation, QA Testing, Website QA, Test Automation Frameworks, Continuous Delivery (CD), Continuous Integration (CI), CI/CD Pipelines, Build Pipelines, cURL Command Line Tool, APIs, Testing, Quality Assurance (QA), SQL, Postman, Fintech, SDET, Software Development, Release Management, Jira, Test Planning, Functional Testing, Agile Software Testing, Confluence, GitHub, E2E Testing, Mobile App Testing, Test Management, Agile, Git, Integration Testing, Software Release Management, System Requirements, Finance, QA Leadership, Automation Tools, Software Testing Lifecycle (STLC), Object-oriented Programming (OOP), Web App Testing, Automation, REST Assured, TypeScript, Non-functional Testing, Microservices, Testing Strategy, UX Testing, Scrum, Test-driven Development (TDD), Test Reporting, DevOps, JSON, Test Data, Accessibility, Web Applications, Unit Testing, Test Cases
Junior QA Tester
2012 - 2013
IG
- Set up a Cucumber, Selenium, and Java grid framework to automate our regression testing, which reduced test cycles from three days to two hours.
- Trained other QAs on-premise and offshore on automated testing.
- Performed manual testing on new features and during releases.
Technologies: Selenium, Selenium Grid, Cucumber, Behavior-driven Development (BDD), Java, Bamboo, Automated Testing, Automated UI Testing, Trading, Stock Trading, Forex Trading, Derivatives, Manual QA, Manual Testing, Manual Software Testing, Fintech, Regression Testing, JavaScript, Website Testing, Website QA, QA Testing, Test Automation, Test Automation Frameworks, Quality Assurance (QA), Continuous Integration (CI), CI/CD Pipelines, APIs, REST APIs, Testing, SDET, Software Development, Localization Testing, Test Planning, Functional Testing, Agile Software Testing, Confluence, GitHub, E2E Testing, Test Management, Agile, TestRail, Git, Test Documentation, System Requirements, Finance, Automation Tools, Software Testing Lifecycle (STLC), Object-oriented Programming (OOP), Web App Testing, UX Testing, Scrum, Test-driven Development (TDD), Test Reporting, JSON, Test Data, Web Applications, Unit Testing, Test Cases
Experience
Automated Testing with BDD for Mobile Apps
A mobile app for MyDrive that analyzes and scores users' driving.
Since Generali, an insurance multinational, acquired the company, the app had to be white-labeled for Generali's subsidiaries. However, they could not release it on time as regression bugs plagued every new feature.
As part of the mobile agency Novoda, I was the first QA to ever work with MyDrive. I introduced a BDD testing framework with tests written in Android and iOS native frameworks and a shared repository of feature files.
We trialed it, and after a month, they already had a 25% reduction in bugs and better communication between developers, designers, and business stakeholders.
MyDrive soon decided to hire a QA team. I conducted the technical assessment part of the hiring process and trained the new joiners, ultimately handing it over once they were up to speed.
Since Generali, an insurance multinational, acquired the company, the app had to be white-labeled for Generali's subsidiaries. However, they could not release it on time as regression bugs plagued every new feature.
As part of the mobile agency Novoda, I was the first QA to ever work with MyDrive. I introduced a BDD testing framework with tests written in Android and iOS native frameworks and a shared repository of feature files.
We trialed it, and after a month, they already had a 25% reduction in bugs and better communication between developers, designers, and business stakeholders.
MyDrive soon decided to hire a QA team. I conducted the technical assessment part of the hiring process and trained the new joiners, ultimately handing it over once they were up to speed.
Selenium BDD Automated Regression Testing
http://www.ig.comIG.com is localized across 15+ locales. Each locale had to be manually regression tested before our monthly releases. In total, we had 80 QAs spending three days per month testing the same sites and trading platforms in every supported browser. They also checked the necessary copy in every language.
Once I started with Selenium, I wrote reusable scenario templates using Cucumber examples on the public-facing websites, which was my responsibility.
The regression testing went from five people over three days to one hour of parallel automated testing on our Selenium grid.
I spent my last month at the company pairing with other QAs based in the UK and India interested in automation, introducing them to automated testing and helping them start adding tests to their areas of responsibility.
Once I started with Selenium, I wrote reusable scenario templates using Cucumber examples on the public-facing websites, which was my responsibility.
The regression testing went from five people over three days to one hour of parallel automated testing on our Selenium grid.
I spent my last month at the company pairing with other QAs based in the UK and India interested in automation, introducing them to automated testing and helping them start adding tests to their areas of responsibility.
Improving Testing Coverage with SonarQube
http://www.capita.comWhile working at Capita, I was given a side-mission by my manager—I used SonarQube and investigated which parts of the legacy codebase needed more Unit tests.
Senior developers were apprehensive because some of them saw meaningless Unit tests being written to boost coverage numbers just for the sake of hitting department objectives. Others saw Unit tests as a low-value box-ticking exercise.
The key insight was that coverage on its own couldn't indicate if we needed to add Unit tests. For example, a module with 70% coverage that constantly gives us critical bugs should be a higher priority than one with 10% coverage that hasn't been changed in years and is treated as a reliable black box.
With this approach, the developers were convinced that adding Unit tests to the suggested parts of code would benefit them since it would reduce bugs and complaints they would have to deal with.
Senior developers were apprehensive because some of them saw meaningless Unit tests being written to boost coverage numbers just for the sake of hitting department objectives. Others saw Unit tests as a low-value box-ticking exercise.
The key insight was that coverage on its own couldn't indicate if we needed to add Unit tests. For example, a module with 70% coverage that constantly gives us critical bugs should be a higher priority than one with 10% coverage that hasn't been changed in years and is treated as a reliable black box.
With this approach, the developers were convinced that adding Unit tests to the suggested parts of code would benefit them since it would reduce bugs and complaints they would have to deal with.
Education
2008 - 2012
Bachelor of Engineering Degree in Artificial Intelligence with Software Engineering
The University of Edinburgh - Edinburgh, UK
Certifications
OCTOBER 2014 - PRESENT
ISTQB Foundation
BCS, The Chartered Institute for IT
Skills
Libraries/APIs
Selenium WebDriver, REST APIs, React, Playwright, Selenium Grid, JaCoCo, Node.js
Tools
Cucumber, Jira, GitHub, TestRail, Git, REST Assured, Visual Studio, Notion, Jenkins, Charles Proxy, Postman, WireMock, SonarQube, Apache JMeter, Apache Tomcat, Bamboo, BrowserStack, Docker Compose, cURL Command Line Tool, Confluence, Xcode, Android Studio, GitLab, GitLab CI/CD, XCUnit
Frameworks
Selenium, Espresso, XCUITest, JUnit, Jest, Cypress, Angular, Cucumberish, Mockito, Appium, ARKit, TestNG, Laravel
Paradigms
Behavior-driven Development (BDD), Page Object Model (POM), Automated Testing, Manual Testing, Test Automation, Software Testing, Continuous Integration (CI), Testing, Functional Testing, E2E Testing, Scrum, Test-driven Development (TDD), Unit Testing, Continuous Delivery (CD), Agile, Object-oriented Programming (OOP), Automation, Non-functional Testing, Microservices, Agile Project Management, Management, REST, Load Testing, Azure DevOps, DevOps
Storage
JSON, Oracle SQL, MongoDB, PostgreSQL
Languages
Java, Gherkin, SQL, Kotlin, Swift, JavaScript, Python, TypeScript
Platforms
Android, iOS, Mobile, Windows, MacOS, Linux, Android TV, Docker, Azure, LangSmith, Testsigma
Other
Quality Assurance (QA), Web Applications, Selenium Page Object, QA Automation, Manual QA, Website QA, QA Testing, Team Mentoring, API Testing, Automated UI Testing, Mobile App Testing, Manual Software Testing, Exploratory Testing, Regression Testing, Website Testing, Test Automation Frameworks, Software QA, UI Testing, SDET, Software Development, Agile Software Testing, Test Management, Test Documentation, Automation Tools, Software Testing Lifecycle (STLC), Web App Testing, Testing Strategy, UX Testing, Test Reporting, Test Data, Startups, Test Cases, Technical Hiring, Team Leadership, Remote Team Leadership, Mobile Device QA Automation, Fintech, CI/CD Pipelines, APIs, Mobile Apps, Test Planning, Hardware Testing, eCommerce, Integration Testing, System Requirements, Mobile Applications, Mobile UI, Audits, Android Testing, Advisory, Video Streaming, Team Management, Accessibility, Performance Optimization, Natural Language Processing (NLP), Software Engineering, Machine Learning, Computer Vision, Robotics, JetBrains IDE, Chrome Extensions, Microsoft Azure, AOSP, Account Management, Financial Management, Technical Documentation, Mentorship, Connected Devices, Trading, Stock Trading, Forex Trading, Derivatives, Performance Testing, Build Pipelines, Localization Testing, Release Management, Augmented Reality (AR), Delivery Management, Software Release Management, Leadership, GitHub Actions, Finance, QA Leadership, Internet of Things (IoT), Offshore Team Management, Firmware, Firmware over the Air (FOTA), Cross-functional Team Leadership, Over-the-top Content (OTT), TV, TV Broadcasting, Broadcasting, LangChain, Artificial Intelligence (AI), Artificial Neural Networks (ANN), Neural Networks, Graphs, Large Language Models (LLMs), Genetic Algorithms, Flowise, Multistage LLM Chains
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