I'm an accomplished Senior Software Engineer with over two decades of proven expertise in designing, developing, and deploying enterprise-scale web applications and modern JavaScript solutions. My specialty lies in the React ecosystem, Node.js backend development, TypeScript, and modern JavaScript frameworks, with demonstrated success in leading cross-functional development teams and delivering mission-critical applications that serve hundreds of thousands of users. Throughout my career, I've consistently delivered innovative frontend and backend JavaScript solutions across diverse industries including healthcare technology, financial services, and e-commerce platforms. My technical leadership has resulted in measurable improvements: 60% performance gains through React optimization and modern JavaScript practices, 40% reduction in bundle sizes via advanced webpack configurations, and deployment time reductions from 4 hours to 15 minutes through automated CI/CD pipelines using Node.js build tools. As a hands-on technical leader, I excel at bridging the gap between complex user experience requirements and scalable backend architecture using the JavaScript ecosystem.

Jason Willey Sr.

I'm an accomplished Senior Software Engineer with over two decades of proven expertise in designing, developing, and deploying enterprise-scale web applications and modern JavaScript solutions. My specialty lies in the React ecosystem, Node.js backend development, TypeScript, and modern JavaScript frameworks, with demonstrated success in leading cross-functional development teams and delivering mission-critical applications that serve hundreds of thousands of users. Throughout my career, I've consistently delivered innovative frontend and backend JavaScript solutions across diverse industries including healthcare technology, financial services, and e-commerce platforms. My technical leadership has resulted in measurable improvements: 60% performance gains through React optimization and modern JavaScript practices, 40% reduction in bundle sizes via advanced webpack configurations, and deployment time reductions from 4 hours to 15 minutes through automated CI/CD pipelines using Node.js build tools. As a hands-on technical leader, I excel at bridging the gap between complex user experience requirements and scalable backend architecture using the JavaScript ecosystem.

Available to hire

I’m an accomplished Senior Software Engineer with over two decades of proven expertise in designing, developing, and deploying enterprise-scale web applications and modern JavaScript solutions. My specialty lies in the React ecosystem, Node.js backend development, TypeScript, and modern JavaScript frameworks, with demonstrated success in leading cross-functional development teams and delivering mission-critical applications that serve hundreds of thousands of users.

Throughout my career, I’ve consistently delivered innovative frontend and backend JavaScript solutions across diverse industries including healthcare technology, financial services, and e-commerce platforms. My technical leadership has resulted in measurable improvements: 60% performance gains through React optimization and modern JavaScript practices, 40% reduction in bundle sizes via advanced webpack configurations, and deployment time reductions from 4 hours to 15 minutes through automated CI/CD pipelines using Node.js build tools. As a hands-on technical leader, I excel at bridging the gap between complex user experience requirements and scalable backend architecture using the JavaScript ecosystem.

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Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
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Language

English
Fluent

Work Experience

Lead Developer at Coloplast
April 1, 2022 - June 11, 2024
Led a dynamic team architecting and building next-generation healthcare applications with React, .NET Core, and Azure cloud. Spearheaded patient management system development serving 50,000+ healthcare professionals. Architected microservices ecosystem with Docker and Azure Kubernetes Service, reducing downtime by 40%. Led .NET Framework to .NET Core migration with 60% performance gain. Established CI/CD pipelines reducing deployment time to 15 minutes. Mentored junior developers improving code quality by 35%. Implemented security measures for HIPAA compliance and optimized database performance with Redis caching.
Sr. Software Engineer at OutSystems
January 1, 2016 - March 31, 2022
Senior engineer on core platform team building React visual development environments and Node.js integration services for 100,000+ developers. Developed C# compiler optimizations improving generation speed by 45%. Implemented real-time collaboration with SignalR/WebSockets for 1,000+ users. Led performance optimizations improving page load times by 50%. Designed advanced caching strategies reducing database load by 60%. Created automated testing suites with 85% coverage and collaborated with UX/UI teams to enhance developer productivity.
Sr. Software Engineer at Castle Harlan
June 1, 2012 - December 31, 2015
Developed financial technology solutions and portfolio management systems for a private equity firm. Built portfolio dashboards with ASP.NET MVC and React managing $2B+ in assets. Automated reporting system reducing manual work by 80%. Developed RESTful APIs serving 500+ institutional clients with real-time data. Created data pipelines processing 10 million+ financial transactions daily. Enhanced security with multi-factor authentication and data encryption. Optimized financial algorithms for 45% performance improvement and ensured 99.9% system availability.
Backend Developer at impact.com
December 1, 2009 - May 31, 2012
Built scalable backend systems for high-volume affiliate marketing platform. Developed tracking system processing 100 million events daily with 99.99% accuracy. Implemented fraud detection reducing invalid traffic by 30%. Created JavaScript widgets for 10,000+ partner websites enabling real-time conversion tracking. Improved database queries and indexing boosting performance by 40%. Developed API endpoints for partner integrations and real-time analytics dashboards for campaign insights.
Full Stack Developer at SimbirSoft
November 1, 2005 - November 30, 2009
Developed enterprise web applications for healthcare, finance, and manufacturing clients. Implemented frontend interfaces with HTML, CSS, JavaScript. Created backend systems with .NET Framework and SQL Server supporting thousands of users. Designed RESTful and SOAP APIs for system integrations. Improved application performance by 50% through database optimization. Ensured security compliance with authentication and data encryption. Collaborated cross-functionally delivering projects on time. Mentored junior developers and implemented automated testing reducing bugs by 40%.
Junior Web Developer at AltSource, Inc
March 1, 2004 - October 31, 2005
Started as junior web developer building dynamic web applications with ASP.NET, C#, and JavaScript. Created responsive user interfaces and implemented database connectivity with SQL Server. Participated in full software development lifecycle and collaborated with senior developers on troubleshooting and best practices. Developed reusable components and implemented basic security features ensuring protection against vulnerabilities. Contributed to legacy system migrations and supported production applications with debugging and fixes.
Lead Developer at Coloplast
April 1, 2022 - June 10, 2024
Leading a dynamic team in architecting and building next-generation healthcare applications serving medical professionals and patients globally. Responsible for both hands-on development and strategic leadership focusing on React-based UIs, .NET Core services, and Azure infrastructure. Spearheaded development of a patient management system serving 50,000+ healthcare professionals, architected a microservices ecosystem with Docker and Azure Kubernetes Service, and led a legacy app migration to .NET Core achieving 60% performance improvements. Established CI/CD pipelines reducing deployment time drastically, mentored junior developers improving code quality, and implemented advanced security measures ensuring HIPAA compliance.
Sr. Software Engineer at OutSystems
January 1, 2016 - March 31, 2022
Senior engineer on the core platform team developing enterprise-grade low-code development tools used by over 100,000 developers. Architected React-based visual development environment with drag-and-drop functionality, Node.js integration services connecting over 200 third-party APIs, and enhanced C# compiler optimizations increasing app generation speed by 45%. Led performance optimizations, implemented real-time collaboration features using SignalR, developed caching strategies to reduce database load, automated testing suites improving code coverage, and worked closely with UX/UI teams to improve developer productivity. Mentored teams on modern JavaScript and .NET Core development.
Sr. Software Engineer at Castle Harlan
June 1, 2012 - December 31, 2015
Developed financial technology and portfolio management systems for a private equity firm managing billions in assets. Built portfolio management dashboards with ASP.NET MVC and React, implemented automated reporting systems reducing manual work by 80%, and developed RESTful APIs serving over 500 institutional clients. Created data integration pipelines processing over 10 million transactions daily and optimized financial calculations by 45%. Implemented advanced security including multi-factor authentication and data encryption, worked with quantitative analysts to develop financial models, and established backup and disaster recovery procedures ensuring 99.9% uptime.
Backend Developer at impact.com
December 1, 2009 - May 31, 2012
Developed scalable backend systems for affiliate marketing focusing on high-volume transaction processing and fraud detection. Built a tracking and attribution system processing over 100 million events daily with near-perfect accuracy, implemented fraud detection algorithms reducing invalid traffic by 30%, and developed JavaScript widgets for seamless partner integration. Optimized database queries improving response times by 40%, created API endpoints for partner integrations, and delivered real-time analytics dashboards monitoring campaign performance and revenue opportunities.
Full Stack Developer at SimbirSoft
November 1, 2005 - November 30, 2009
Full stack developer delivering enterprise web applications and custom solutions across healthcare, finance, and manufacturing sectors. Developed web apps using ASP.NET, C#, and JavaScript, built responsive frontends with HTML, CSS, and JavaScript, and implemented scalable backend systems. Designed RESTful and SOAP APIs for integration, optimized database performance by 50%, ensured security compliance, collaborated with cross-functional teams, implemented automated testing and CI reducing bugs by 40%, and mentored junior developers.
Junior Web Developer at AltSource, Inc
March 1, 2004 - October 31, 2005
Started career as a junior web developer working on dynamic web applications with ASP.NET, C#, and JavaScript. Created responsive UIs, implemented database connectivity with SQL Server and ADO.NET, participated in software lifecycle from design to deployment, collaborated on troubleshooting and best practices, developed reusable components, implemented basic security features, participated in code reviews and testing, contributed to legacy system migrations, supported production applications, and demonstrated strong learning ability.
Lead Developer at Coloplast
April 1, 2022 - June 5, 2024
Leading a dynamic team in architecting and building next-generation healthcare applications with React 18, TypeScript, .NET 6 Web API, and Azure cloud infrastructure. Spearheaded the development of a patient management system serving over 50,000 healthcare professionals, architected a microservices ecosystem with Docker and AKS reducing downtime by 40%, migrated legacy .NET Framework apps to .NET Core achieving 60% improvement in performance, and implemented comprehensive CI/CD pipelines reducing deployment time from 4 hours to 15 minutes. Mentored junior developers and established security to ensure HIPAA compliance.
Sr. Software Engineer at OutSystems
January 1, 2016 - March 31, 2022
Served as senior engineer on core platform team building low-code development tools with a focus on React-based environments, Node.js integration services, and C# compiler optimizations. Architected React-based visual tools supporting 100,000 developers, developed Node.js integrations with 200+ APIs, improved application generation speed by 45%, implemented real-time collaboration, improved platform performance by 50%, and established advanced caching with Redis. Also led automated testing suite development and mentored teams on modern development practices.
Sr. Software Engineer at Castle Harlan
June 1, 2012 - December 31, 2015
Developed financial technology solutions including portfolio management dashboards, automated regulatory reporting systems, and robust RESTful APIs serving institutional clients. Enhanced data integration pipelines processing millions of daily transactions, implemented multi-factor authentication and data encryption for security compliance, and optimized financial algorithms improving system performance by 45%. Collaborated with quantitative analysts to translate complex models into maintainable code and established backup and disaster recovery procedures.
Backend Developer at impact.com
December 1, 2009 - May 31, 2012
Developed scalable backend systems focused on transaction processing, fraud detection, and analytics for an affiliate marketing platform. Built tracking and attribution systems processing over 100 million events daily, implemented fraud detection reducing invalid traffic by 30%, developed JavaScript widgets for partner site integration, optimized database performance achieving 40% faster response, and created APIs enabling real-time campaign management and analytics dashboards.
Full Stack Developer at SimbirSoft
November 1, 2005 - November 30, 2009
Developed enterprise web applications using ASP.NET, C#, JavaScript and SQL Server across healthcare, finance, and manufacturing sectors. Built responsive frontends and robust backend systems supporting thousands of users, designed RESTful and SOAP APIs for integration, optimized SQL queries for performance, implemented security features for compliance, and collaborated with cross-functional teams to deliver projects timely. Mentored junior developers and improved code quality through automated testing and CI practices.
Junior Web Developer at AltSource, Inc
March 1, 2004 - October 31, 2005
Started professional career developing dynamic web applications using ASP.NET, C#, JavaScript, HTML, CSS, and SQL Server. Participated in full software lifecycle including requirements gathering, implementation, testing and deployment. Collaborated with senior developers, implemented user authentication and input validation, maintained reusable web components, supported legacy system migration, and provided production support. Developed foundational web development skills that enabled advancement to senior roles.
Lead Developer at Coloplast
April 1, 2022 - Present
Leading a dynamic team in architecting and building next-generation healthcare applications using modern JavaScript technologies. Role encompasses hands-on React/Node.js development and strategic technical leadership, focusing on React-based user interfaces, Node.js backend services, and cloud-native JavaScript solutions. Spearheaded the development of a comprehensive patient management system using React 18, Vue.js for admin dashboards, TypeScript, and Node.js Express APIs, serving over 50,000 healthcare professionals across North America and Europe. Architected and implemented a robust Node.js microservices ecosystem using Docker containers, resulting in a 40% reduction in system downtime and improved fault tolerance. Successfully led the complete migration of legacy server applications to modern Node.js with Express.js, achieving a 60% improvement in API response times and significantly reduced memory footprint. Established comprehensive CI/CD pipelines using AWS CodePipeline and Az
Senior Software Engineer at OutSystems
January 1, 2022 - August 19, 2025
Served as a senior engineer on the core platform team, developing enterprise-grade low-code development tools using cutting-edge React and Node.js technologies. Contributions focused on building sophisticated React-based development environments, robust Node.js integration services, and high-performance JavaScript compiler optimizations empowering over 100,000 developers worldwide. Architected and built a revolutionary React-based visual development environment with Angular components for enterprise integrations featuring advanced drag-and-drop functionality using React DnD, comprehensive component libraries with Storybook, and real-time preview capabilities using React Hot Reload supporting over 100,000 active developers globally. Developed comprehensive Node.js integration services seamlessly connected to more than 200 third-party APIs and enterprise systems, including Salesforce, SAP, Oracle, and custom REST/GraphQL services using Express.js, with Python scripts for data transformat
Senior Software Engineer at Castle Harlan
January 1, 2016 - August 19, 2025
Developed sophisticated financial technology solutions and portfolio management systems using modern JavaScript technologies for a leading private equity firm managing billions in assets. Work focused on creating secure, high-performance React applications and Node.js APIs to support investment decisions and regulatory compliance. Built a comprehensive portfolio management dashboard using React, Angular for trading interfaces, and Vue.js for reporting modules, with Node.js Express APIs and PostgreSQL database, providing real-time insights and analytics for investment portfolios exceeding $2 billion in total assets under management. Implemented a fully automated reporting system using Node.js with Python data processing scripts for complex financial calculations, generating regulatory compliance reports, investor statements, and performance analytics, reducing manual processing work by 80% and eliminating human error. Developed robust RESTful APIs using Express.js and Firebase for real-
Back-End Developer at impact.com
January 1, 2012 - August 19, 2025
Developed highly scalable Node.js backend systems for a leading affiliate marketing platform, focusing on high-volume transaction processing, fraud detection, and real-time analytics. Contributions enabled the platform to handle massive traffic loads while maintaining accuracy and performance using modern JavaScript technologies. Built a sophisticated tracking and attribution system using early Node.js implementations with custom frameworks, capable of processing over 100 million events daily with sub-second response times and 99.99% accuracy through efficient event streaming and MongoDB optimization. Implemented advanced fraud detection algorithms using server-side JavaScript and custom algorithms that reduced invalid traffic by 30%, protecting advertisers from fraudulent activities and improving campaign ROI. Developed lightweight JavaScript widgets embedded on more than 10,000 partner websites, using vanilla JavaScript with ES5 features and jQuery, enabling seamless integration and
Full Stack Developer at Simbir Soft
December 1, 2009 - August 19, 2025
Served as a full stack JavaScript developer for a rapidly growing software development company, specializing in enterprise web applications and custom software solutions. Role involved working with both frontend and backend JavaScript technologies to deliver comprehensive solutions that met complex business requirements. Developed comprehensive web applications using advanced JavaScript with jQuery and AJAX implementations, server-side JavaScript with Rhino and early server-side frameworks, serving clients in healthcare, finance, and manufacturing sectors with custom business solutions. Built responsive frontend interfaces using HTML5, CSS3, and advanced JavaScript including ES patterns, jQuery for DOM manipulation and animations, ensuring cross-browser compatibility and optimal user experience across desktop and mobile devices. Implemented robust backend systems using server-side JavaScript engines like Rhino and V8, with custom database abstraction layers for MySQL and PostgreSQL, cr
Junior Web Developer at AltSource
November 1, 2005 - August 19, 2025
Started my professional career as a junior web developer, gaining foundational experience in web development technologies and establishing expertise in client-side and server-side JavaScript development that would become the foundation for my specialization in modern JavaScript frameworks. Developed dynamic web applications using JavaScript with DOM manipulation, jQuery for enhanced functionality, and AJAX implementations using XMLHttpRequest, contributing to the company's portfolio of interactive web-based business solutions. Created responsive user interfaces using HTML, CSS, and JavaScript DOM manipulation, ensuring optimal user experience across different browsers and implementing early responsive design patterns using JavaScript and CSS. Implemented client-server communication using XMLHttpRequest and early JSON APIs with server-side technologies, enabling efficient data exchange and dynamic content updates without full page reloads. Participated in the complete software developme
Lead Developer at Coloplast
April 1, 2022 - Present
Led a dynamic team architecting and building next-generation healthcare applications using modern JavaScript technologies including React 18, Vue.js for admin dashboards, TypeScript, and Node.js Express APIs. Spearheaded development of a comprehensive patient management system serving over 50,000 healthcare professionals across North America and Europe. Architected and implemented a robust Node.js microservices ecosystem with Docker containers, reducing system downtime by 40% and improving fault tolerance. Successfully led migration of legacy server applications to modern Node.js with Express.js, achieving 60% improvement in API response times and significantly reduced memory footprint. Established comprehensive CI/CD pipelines with AWS CodePipeline and Azure DevOps, automating testing and deployment, reducing deployment time from 4 hours to 15 minutes. Developed Python-based data processing scripts for OCR and computer vision systems to extract patient information, improving data accu
Senior Software Engineer at OutSystems
January 1, 2022 - August 19, 2025
Served as a senior engineer on the core platform team, developing enterprise-grade low-code development tools using cutting-edge React and Node.js technologies. Built sophisticated React-based development environments, robust Node.js integration services, and high-performance JavaScript compiler optimizations empowering over 100,000 developers worldwide. Architected and built a revolutionary React-based visual development environment with Angular components for enterprise integrations featuring advanced drag-and-drop functionality using React DnD and Storybook libraries. Developed comprehensive Node.js integration services connecting more than 200 third-party APIs and enterprise systems including Salesforce, SAP, Oracle, and custom REST/GraphQL services. Created groundbreaking JavaScript compiler optimizations and React code generation improvements boosting application generation speed by 45%, dramatically reducing enterprise development time. Developed custom CLI tools for automated c
Senior Software Engineer at Castle Harlan
January 1, 2016 - August 19, 2025
Developed sophisticated financial technology solutions and portfolio management systems using modern JavaScript technologies for a leading private equity firm managing billions in assets. Built a comprehensive portfolio management dashboard using React, Angular, and Vue.js with Node.js Express APIs and PostgreSQL database delivering real-time analytics for portfolios exceeding $2 billion in assets under management. Implemented a fully automated reporting system using Node.js with Python data processing scripts for complex financial calculations generating regulatory compliance reports, investor statements, and performance analytics reducing manual processing by 80% and eliminating human error. Developed robust RESTful APIs using Express.js and Firebase for real-time data synchronization serving over 500 institutional clients with portfolio data, market insights, and investment opportunities. Created sophisticated data integration pipelines using Node.js streams and Python for processin
Backend Developer at impact.com
January 1, 2012 - August 19, 2025
Developed highly scalable Node.js backend systems for leading affiliate marketing platform focused on high-volume transaction processing, fraud detection, and real-time analytics. Built sophisticated tracking and attribution system using early Node.js implementations capable of processing over 100 million events daily with sub-second response times and 99.99% accuracy via efficient event streaming and MongoDB optimization. Implemented advanced fraud detection algorithms using server-side JavaScript custom methods reducing invalid traffic by 30% protecting advertisers from fraudulent activities and improving campaign ROI. Developed lightweight JavaScript widgets embedded on more than 10,000 partner websites using vanilla JavaScript with ES5 features and jQuery enabling seamless integration and real-time conversion tracking across diverse web platforms. Optimized critical database queries using custom MongoDB drivers and PostgreSQL optimization techniques implementing advanced indexing s
Full Stack Developer at Simbir Soft
December 1, 2009 - August 19, 2025
Served as a full stack JavaScript developer for a rapidly growing software development company specializing in enterprise web applications and custom software solutions. Worked with both frontend and backend JavaScript technologies to deliver comprehensive solutions meeting complex business requirements. Developed comprehensive web applications using advanced JavaScript with jQuery and AJAX implementations, server-side JavaScript with Rhino and early server-side frameworks serving clients in healthcare, finance, and manufacturing sectors with custom business solutions. Built responsive frontend interfaces using HTML5, CSS3, and advanced JavaScript including ES patterns and jQuery for DOM manipulation and animations ensuring cross-browser compatibility and optimal user experience across desktop and mobile devices. Implemented robust backend systems using server-side JavaScript engines like Rhino and V8 with custom database abstraction layers for MySQL and PostgreSQL creating scalable da
Junior Web Developer at Alt Source
November 1, 2005 - August 19, 2025
Started professional career as a junior web developer gaining foundational experience in web development technologies and establishing expertise in client-side and server-side JavaScript development that became foundation for specialization in modern JavaScript frameworks. Developed dynamic web applications using JavaScript with DOM manipulation, jQuery for enhanced functionality, and AJAX implementations using XMLHttpRequest contributing to company's portfolio of interactive web-based business solutions. Created responsive user interfaces using HTML, CSS, and JavaScript DOM manipulation ensuring optimal user experience across different browsers and implementing early responsive design patterns using JavaScript and CSS. Implemented client-server communication using XMLHttpRequest and early JSON APIs with server-side technologies enabling efficient data exchange and dynamic content updates without full page reloads. Participated in complete software development lifecycle from requiremen

Education

Bachelor of Science at Minnesota State University
April 1, 1998 - August 31, 2002
Bachelor of Science at Minnesota State University Mankato
April 1, 1998 - August 31, 2002
Bachelor of Science at Minnesota State University Mankato
April 1, 1998 - August 31, 2002
Bachelor of Science in Computer Science at Mankato Minnesota State University
January 1, 1994 - April 1, 1998
Bachelor of Science in Computer Science at Mankato Minnesota State University
January 1, 1994 - April 1, 1998

Qualifications

Microsoft Certified: Azure Solutions Architect Expert
January 1, 2023 - December 31, 2023
AWS Certified Solutions Architect - Professional
January 1, 2022 - December 31, 2022
Microsoft Certified: Azure Developer Associate
January 1, 2021 - December 31, 2021
Certified Kubernetes Administrator (CKA)
January 1, 2021 - December 31, 2021
Microsoft Certified Solutions Developer (MCSD)
January 1, 2019 - December 31, 2019
Scrum Master Certified (SMC)
January 1, 2018 - December 31, 2018
Microsoft Certified: Azure Solutions Architect Expert
January 1, 2023 - December 31, 2023
AWS Certified Solutions Architect - Professional
January 1, 2022 - December 31, 2022
Microsoft Certified: Azure Developer Associate
January 1, 2021 - December 31, 2021
Certified Kubernetes Administrator (CKA)
January 1, 2021 - December 31, 2021
Microsoft Certified Solutions Developer (MCSD)
January 1, 2019 - December 31, 2019
Scrum Master Certified (SMC)
January 1, 2018 - December 31, 2018
Hackerrank Certificated: C# Developer
January 1, 2025 - December 31, 2025
Microsoft Certified: Azure Solutions Architect Expert
January 1, 2023 - December 31, 2023
AWS Certified Solutions Architect - Professional
January 1, 2022 - December 31, 2022
Microsoft Certified: Azure Developer Associate
January 1, 2021 - December 31, 2021
Certified Kubernetes Administrator (CKA)
January 1, 2021 - December 31, 2021
Microsoft Certified Solutions Developer (MCSD)
January 1, 2019 - December 31, 2019
Scrum Master Certified (SMC)
January 1, 2018 - December 31, 2018
Hackerrank Certificated: C# Developer
January 1, 2025 - December 31, 2025

Industry Experience

Healthcare, Financial Services, Software & Internet, Manufacturing, Retail, Professional Services