Yosuan Crespo
EXPERTISE
BIO
Results-driven Senior QA Engineer with a Computer Science Engineering background and 17 years of proven expertise in both manual and automated testing across web, mobile (iOS, Android), API and blockchain platforms. Skilled in architecting end-to-end test strategies, leveraging JavaScript, TypeScript, Python, Java, SQL and industry-leading frameworks (Cypress, Selenium, Appium, Playwright, Pytest), within Agile (Scrum, Kanban) environments and CI/CD pipelines, consistently reducing critical defects and accelerating release cycles. Bilingual (English-Spanish) and collaborative leader who has mentored high-performance QA teams, driven TDD/BDD adoption and stepped into Project Manager roles to align quality initiatives with broader business objectives. Owns an LLC.
WORK EXPERIENCE
Senior QA Engineer and Project Manager
Blubird
January 2024 - Present
• Architect QA strategy for a Web3, cryptocurrency platform. Validate smart contracts for Decentralized Applications (DApps) on Ethereum, Solana, BSC and other blockchains, performing crypto-transaction testing and vulnerability assessments using Python. • Develop test suites (E2E, functional, exploratory, UAT, usability, accessibility, database (SQL, NoSQL), security) for React, Node.js apps, using Playwright, Pytest, Cucumber, Katalon and Postman to cover UI and RESTful APIs. • Manage CI/CD & cloud integration with GitLab CI, Jenkins and AWS ensuring scalability, availability and secure delivery, decreasing build failures by 25% and maintaining 99.9% system uptime. • Ensure effective team communication and collaboration, fulfilling Project Manager duties during some periods. • Key Technologies & Tools: Python, Ethereum, Solana, BSC, SQL, NoSQL, React, Node.js, Playwright, Pytest, Cucumber, Katalon, Postman, RESTful API, GitLab CI, Jenkins, AWS, JavaScript, TypeScript, Java, Maven, HTML, CSS, MySQL, Oracle, Visual Studio Code, GitLab, Git, GitHub, Cypress, Selenium, JUnit, TestNG, Allure, REST Assured, REST, XML, SOAP, Jira, Confluence, TestRail, TestProject, Gatling, JMeter, Zapier, Notion, ClickUp, LastPass, BambooHR, Fireblocks, Slack.
Senior QA Engineer
BairesDev
April 2021 - May 2025
• Led the QA team of 4+ engineers by defining a comprehensive QA strategy, encompassing Manual and Automation testing, within an Agile (Scrum, Kanban) framework to increase test coverage. Managed full Defect Management lifecycle in Jira, Confluence and Zephyr, foster collaboration and mentor team members. • Designed & executed comprehensive test suites through functional, end-to-end, manual, exploratory, usability, database, black box & security testing, leveraging Postman, GraphQL, Datadog insights, MySQL checks and OWASP best practices; this thorough testing contributed significantly to the iOS app achieving an 8x higher conversion rate compared to the web. • Built & maintained automation frameworks in JavaScript, Java & TypeScript using Cypress, Selenium, Appium (iOS, Android), integrated with CI/CD pipelines (Git, Bitbucket, CircleCI), BrowserStack and LambdaTest for cross platform coverage ensuring compliance with high quality releases. • Drove TDD, BDD adoption by crafting unit, API, integration, regression, smoke & performance tests (JMeter, Gatling, LoadRunner), reducing critical production defects by 40% through rigorous test design and attention to details. • Key Technologies & Tools: Jira, Confluence, Zephyr, Postman, GraphQL, Datadog, MySQL, OWASP, iOS, Android, JavaScript, Java, TypeScript, Cypress, Selenium, Appium, Git, Bitbucket, CircleCI, BrowserStack, LambdaTest, JMeter, Gatling, LoadRunner, Swift, Xcode, TestFlight, Sourcetree, GitHub, Insomnia, Visual Studio Code, Figma, Mixpanel, Firebase, AppsFlyer, Slack, Loom.
QA Lead and Project Manager
Freeway
September 2022 - July 2023
• Led the team, defining and executing a comprehensive test strategy (Manual & Automated) while simultaneously overseeing project execution within an Agile framework, for the integration with the Bitcoin network and DeFi applications. • Implemented full-stack automation integrated into Azure and mentored QA Engineers, reducing critical bugs in production by 35% and accelerating release cycles by 25%. • Executed a wide range of testing types: Unit, API, Automation (Cypress, Selenium, Playwright, Postman), E2E, Regression, Smoke, Integration, Exploratory, UAT and Cross-Functional (performance with Gatling and JMeter, Security, Compatibility, Usability, Accessibility, Scalability). • Specialized in testing blockchain transactions for decentralized finance products across networks including BNB Smart Chain, Ethereum, BSC Testnet and Goerli, utilizing tools like Fireblocks. • Applied Cloudflare features to enhance website security and performance, incorporating relevant testing procedures. • Managed the complete project lifecycle using Agile practices (Scrum, Kanban), including sprint planning, backlog grooming, task prioritization and stakeholder communication via Jira and Notion. • Key Technologies & Tools: JavaScript, TypeScript, Java, Maven, Python, React, HTML, CSS, MySQL, Oracle, Node.js, Visual Studio Code, AWS, Azure, GitLab, Git, GitHub, Jenkins, Cypress, Selenium, Playwright, Postman, JUnit, TestNG, Allure, REST Assured, RESTful API, XML, SOAP, TestRail, TestProject, Gatling, JMeter, Fireblocks, Cloudflare, Jira, Confluence, Zapier, Notion, ClickUp, LastPass, BambooHR, Slack.
Regional Manager and Business Developer
Rentible
April 2022 - May 2023
• Pioneered Web3 adoption in real estate by spearheading regional management and business development for Rentible, a cutting-edge platform facilitating crypto-based property rentals via smart contracts. • Represented Rentible at The Capital 2022 Metaverse Conference (CoinMarketCap), generating 10+ high-value leads and expanding brand visibility in the crypto ecosystem. • Secured strategic partnerships with 12 real-estate agencies and proptech startups, boosting platform listings by 150% and driving a 4x increase in monthly rental volume using Salesforce. • Onboarded 40+ new clients, property owners and asset managers, by guiding them through smart-contract setup, KYC/compliance and platform integration. • Conducted 25+ stakeholder interviews and needs-analysis sessions to refine user journeys, resulting in a 25% uptick in user engagement metrics. • Audited and optimized website UX/UI, collaborating with designers and developers to improve load times by 40% and streamline the rental workflow. • Authored comprehensive user guides, FAQs and video tutorials that reduced onboarding support tickets by 65%. • Led investor outreach and due-diligence efforts, closing a pre-seed round and establishing ongoing VC relationships. • Orchestrated PR campaigns across crypto and real-estate media channels, securing press and amplifying social media community growth by 300%.
Senior QA Engineer
ThoughtWorks
August 2020 - April 2021
• Acted as QA Engineer and Architect, Product Owner, Project Manager and Business Analyst, shaping end-to-end test strategy and ensuring alignment with product roadmaps. • Led a cross-functional QA team of 4+ engineers, embedding Scrum, Kanban, TDD and BDD practices that increased automated test coverage to 90% and slashed regression cycles by 50%. • Designed and implemented comprehensive test suites (unit, automation (Selenium, Cypress, Playwright, Pytest), E2E, regression, smoke, integration, exploratory, cross-functional and A/B testing), uncovering critical defects before production. • Collaborated with developers to review unit tests, refine user stories, triage bugs and manage technical debt, improving sprint predictability by 30%. • Orchestrated sprint planning, backlog grooming and retrospectives in Jira, Confluence, driving continuous process enhancements and stakeholder transparency. • Applied SEO best practices and analytics strategies (Google Analytics, Adobe Analytics, Google Tag Manager) to boost e-commerce engagement by 25%. • Key Technologies & Tools: JavaScript, TypeScript, Java, Maven, Python, React, HTML, CSS, MySQL, Oracle, .NET, Node.js, AWS, GitLab, Git, Jenkins, Selenium, Cypress, Playwright, Pytest, Postman, JUnit, TestNG, Allure, REST Assured, RESTful API, XML, SOAP, Kibana, Grafana, Google Data Studio, Google Tag Manager, Google Analytics, Adobe Analytics, Jira, Confluence, Contentful, WordPress, Drupal, Gatling, JMeter, Visual Studio Code, Slack, Webex.
Senior QA Engineer and Project Manager
Independent Consultant
July 2015 - July 2020
• Delivered QA and project management services for 8 clients across fintech, e-commerce, healthcare and SaaS, reducing critical defects by 50% and accelerating release cycles by 40% in average. • Architected and implemented robust automation frameworks (Cypress, Selenium, Playwright, Appium, Pytest) in JavaScript, TypeScript, Java and Python, integrating with CI/CD pipelines (Jenkins, GitLab) to ensure consistent, high-quality releases. • Developed and launched 8 responsive websites (Drupal, WordPress, React) with tailored SEO strategies that boosted organic traffic by an average of 35% and improved lead conversion by 20%. • Planned and executed diverse testing scopes, unit, E2E, regression, smoke, integration, exploratory, A/B and cross-functional (performance via Gatling & JMeter, security, scalability, compatibility, usability, accessibility), for both web and API projects. • Advised startups and SMEs on digital marketing, social media growth and online advertising, delivering campaigns that achieved up to 5x ROI. • Conducted market research and go-to-market planning for product launches in North America, Europe and Latin America, supporting clients’ market entry and fundraising efforts. • Key Technologies & Tools: JavaScript, TypeScript, Java, Maven, Python, React, HTML, CSS, PHP, MySQL, Oracle, .NET, C, C#, C++, Node.js, Visual Studio Code, Salesforce, AWS, GitLab, Git, GitHub, Jenkins, Cypress, Selenium, Appium, Playwright, Pytest, BrowserStack, Postman, TestCafe, JUnit, TestNG, Allure, REST Assured, RESTful API, XML, SOAP, Kibana, Grafana, Google Data Studio, Google Tag Manager, Google Analytics, Adobe Analytics, Jira, Confluence, TestRail, TestProject, Gatling, JMeter, Slack.
QA Engineer and Project Manager
EspacioCuba
December 2012 - July 2015
• Defined and validated functional requirements for the national real-estate portal and agency websites, writing and executing test plans to ensure 100% coverage. • Managed office network infrastructure, provided support and maintained a high availability of internal systems. • Employed data analytics and BI tools to surface usage insights, enabling targeted feature enhancements and process refinements. • Key Technologies & Tools: Wordpress, PHP, Symfony, Linux, Apache, HTML, CSS, JavaScript, Ajax, MySQL, SQL, RUP.
QA Engineer and Project Manager
University of Computer Sciences
September 2008 - August 2012
• Led student teams as Project Manager for significant academic software projects within the university environment. • Managed the development lifecycle of a Medical Genetics Computer System (PHP, Symfony) designed to manage patient data for genetic diseases. • Served as Project Manager for EPIGEN, a statistical analysis tool for Genetic Epidemiology research, facilitating the study of genetic and environmental factors in complex diseases. • Worked as QA Engineer defining and implementing systematic activities and testing plans (Functional, Regression, Usability, Compatibility, Security, Performance) using RUP methodology principles across various software projects. • Key Technologies & Tools: PHP, Symfony, Linux, Apache, HTML, CSS, JavaScript, Ajax, MySQL, SQL, Java, RUP.
EDUCATION
Engineer's degree
University of Computer Sciences, July 2008
Computer Science Engineering
CERTIFICATIONS
Scrum Foundation Professional Certificate
Certiprof
Issued: 3/15/2022
EF SET English Certificate
EF SET
Issued: 8/16/2020
PORTFOLIO PROJECTS
Freeway
Make finance more rewarding for everyone.
9/1/2022 -7/31/2023
Rentible
Web3 company, the platform for renting real estate using crypto through a smart contract.
View Project4/1/2022 -5/31/2023
Verified QA Engineer
8+ years of experience
Preferred commitment: Full Time
Languages
Skills
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