David Stone
Verified Expert in Engineering
QA Engineer and Developer
Philadelphia, PA, United States
Toptal member since November 14, 2025
David is a senior QA engineer with 10+ years of experience in software testing and quality assurance. He specializes in API testing with Postman, automation using Playwright with .NET, and cross-functional collaboration in Agile environments. Skilled in Git, Azure DevOps, and CI/CD workflows, with hands-on development experience in Java, Python, PHP, .NET, and JavaScript, David is known for delivering reliable, scalable test solutions and bridging QA with development to drive product excellence.
Portfolio
Experience
- SQL - 10 years
- APIs - 10 years
- QA Testing - 10 years
- Postman - 10 years
- MySQL - 10 years
- Scrum - 6 years
- Product Lifecycle Management (PLM) - 5 years
- Playwright - 3 years
Preferred Environment
Postman, SQL, .NET, Playwright, Azure, DevOps, Scrum, TestRail, Product Lifecycle Management (PLM), APIs
The most amazing...
...thing I've done is enhancing the quality of the application and testing process, enabling the company to maintain high-quality production.
Work Experience
Senior QA Engineer
Church Pension Group
- Designed and planned a strategy for API testing through Postman and Newman.
- Reduced manual regression time by 40% using automation end-to-end scenarios with Playwright.
- Championed continuous improvement in QA processes, aligning testing efforts with business priorities and resource constraints, increasing QA performance up to 70%.
- Designed and executed functional, regression, smoke, and sanity testing on five different projects.
- Enhanced API documentation by making more than 3,000 changes.
- Run the Agile ceremonies, such as the daily scrum, refinement, sprint planning, and retrospective meetings.
- Performed data validation on ETL testing across various databases, including MongoDB, Oracle, and MySQL.
- Created Domo cards for management reporting and visualization of our work progress and availability.
Senior QA Engineer
Gap
- Performed functional, regression, performance, API, and load testing across multiple environments. Ensured stability and scalability of retail workflows by creating up to 20 test cases for each story.
- Validated data transformation logic and JSON schema mappings against source-to-target specifications.
- Reduced the number of regression test cases from over 300 to 100-150 for each module by combining them and removing duplicate steps.
- Authored and maintained test documentation, including test plans, test cases, and reports. Facilitated scrum ceremonies, retrospectives, and sign-off meetings.
- Led data migration validation efforts. Wrote SQL queries, prepared CSV/XML files, and ensured data integrity during system transitions.
- Shared knowledge transfer (KT) recordings and documentation via Confluence to support cross-team learning.
QA Engineer
Advanced Neurology
- Designed and implemented testing strategies for data ingestion, transformation, and validation pipelines to ensure data quality and accuracy.
- Performed functional, regression, and end-to-end testing for authorization workflows and reporting modules.
- Developed and tested REST APIs. Scripted response formatting and transformation using Laravel (PHP/JavaScript).
- Used Postman and JSON to validate API endpoints, token authorization, and web service data flow.
QA Engineer
3G Capital
- Analyzed business requirements and mapped documents to design robust test cases and SQL-based test scenarios.
- Performed functional, regression, and end-to-end testing for trade booking, reporting, and ETL pipelines using Python and SQL.
- Validated ETL workflows from staging to the target data warehouse. Ensured data integrity across feeds from multiple source systems.
- Managed and validated Control-M job dependencies and job statuses (ON ICE, ON HOLD, etc.) for batch processing.
- Automated test execution via Jenkins CI/CD pipelines. Developed and maintained Postman collections for API regression testing.
QA Engineer
McGraw Hill Financial
- Analyzed business process flows for fixed income and derivative products, documented QA activities for system enhancements.
- Validated data flow from the back end to GUI using advanced SQL queries across MS SQL Server databases.
- Authored and maintained test plans, test scenarios, and test cases. Executed manual testing across multiple application components.
- Created and reviewed test artifacts using HP Quality Center and ALM. Managed defects using Jira.
- Performed ETL testing to validate data extraction, transformation, and loading workflows. Developed test scripts based on business requirement documents (BRDs).
- Executed diverse testing types, including functional, regression, system integration, security, UAT, and device compatibility.
QA Engineer
Sum Effect Software
- Developed a comprehensive test strategy, test scenarios, and test cases based on business requirements. Executed manual tests using HP Quality Center (ALM).
- Maintained the requirement traceability matrix to ensure full coverage of use cases.
- Utilized FIX protocol and analyzed FIX logs to troubleshoot trade messaging issues. Tested trade order management systems (TOMS) for end-to-end trade lifecycle.
- Authored detailed defect reports and formal acceptance test procedures. Participated in regular walkthroughs and defect triage meetings.
- Conducted back-end testing using SQL Server and MySQL. Validated ETL processes and data integrity in the Enterprise Data Warehouse (EDW).
- Performed GUI testing to ensure alignment with user requirements and design standards.
- Collaborated with stakeholders to gather and refine user requirements for test case development.
Experience
Aytiqaqash
• A dedicated YouTube channel where I publish high-quality tutorials on QA methodologies, automation frameworks, e.g., Playwright and JavaScript, API testing, and real-world SDLC/STLC practices.
• A complementary Udemy profile offering structured, case-based courses designed to simulate real workplace scenarios and reduce onboarding stress for junior engineers.
The core mission is to create accessible, culturally relevant resources in Azerbaijani, helping students and aspiring professionals gain practical skills and confidence before entering the workforce.
Education
Master of Business Administration (MBA) in IT Management
Azerbaijan State Industry and Oil University - Baku, Azerbaijan
Bachelor's Degree in Information Technology and Systems Engineering
Azerbaijan State Construction and Architecture University - Baku, Azerbaijan
Skills
Libraries/APIs
Playwright, MuleSoft API, Stripe
Tools
Postman, TestRail, Jira, Domo, BrowserStack, MATLAB, Confluence, Control-M, HP Application Lifecycle Management (ALM)
Languages
SQL, HTML, CSS, Visual Basic, Excel VBA, C#, JavaScript, PHP, XML, Python, Snowflake
Paradigms
E2E Testing, Functional Testing, Manual Testing, Testing, Scrum, Agile, Automated Testing, DevOps, Object-oriented Programming (OOP), Automation, Load Testing, Test Automation
Frameworks
Laravel, .NET, Ruby on Rails 6
Platforms
Android, iOS, Apple, Azure, SharePoint, Amazon Web Services (AWS), Amazon EC2, Docker, Linux, YouTube
Storage
MySQL, JSON, Databases, Amazon S3 (AWS S3)
Other
QA Testing, UI Testing, QA Automation, API Testing, Communication, Quality Assurance (QA), Manual QA, Test Case Execution, Test Case Creation, API Integration, Manual Software Testing, Testing Services, Web Service Testing, Attention to Detail, Interviewing, Product Lifecycle Management (PLM), APIs, Software Development Lifecycle (SDLC), Microsoft Office, Waterfall, Newman CLI, Data Migration Testing, Integration Testing, RESTFul APIs, ETL Testing, Regression, Integration, Regression Testing, Coaching, Mobile App Testing, QA Leadership, Test Management, Software QA, iPhone, SAP CRM, SaaS, AI Testing, Code Review, Screeners, Written Communication, Finance, Organizational Behavior (OB), IT Management, Analytics, Networking, Algorithms, Machine Learning, Optimization, Economics, Mathematical Analysis, MuleSoft Anypoint Platform, Enterprise Data Warehouse (EDW), Deployment, Production Support, Jobs, FIX Protocol, FTP Servers, Video Editing, Content Creation, Blogging, Team Leadership, Team Management
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
Share your needs
Choose your talent
Start your risk-free talent trial
Top talent is in high demand.
Start hiring