Charlie Spalevic
Senior Software Engineer
Senior Software Engineer with a proven record of delivering high-impact products and driving modernization of large-scale systems. Led key initiatives at PayPal including Pay Later virtual card launches, high-conversion A/B experiments, and the Quantum Leap rebuild of Checkout into a Next.js platform. Skilled in architecting scalable frontend and backend systems, enhancing observability with Datadog, and building AI-driven tools to accelerate debugging and analysis. Passionate about crafting seamless customer experiences, optimizing performance, and building solutions that scale globally.
PayPal
Senior Software Engineer
Started on PayPal’s Global Pay Later team, contributing to the development of new virtual card experiences, then transitioned to the core Checkout team where I grew into lead roles on major initiatives. Delivered end-to-end solutions across frontend, backend, experimentation, and observability, and played a founding role in the Quantum Leap program to modernize PayPal Checkout with Next.js.
Key Accomplishments:
- •Promoted to Senior Software Engineer for driving critical product and architecture initiatives across GPL and Checkout teams.
- •Developed Pay Later Virtual Card application, including core UI components and backend service integrations.
- •Designed and launched multiple high-impact A/B experiments to improve conversion and checkout performance.
- •Founding member of Quantum Leap, leading early architecture, performance optimization, and component development for a complete Next.js rebuild of PayPal Checkout.
- •Implemented observability best practices with Datadog Metrics and RUM to monitor performance, detect bottlenecks, and improve production reliability.
- •Built AI-powered agents using Mastra to analyze and debug user sessions, reducing time-to-resolution for critical issues.
Spraying Systems
Application Developer
Developed and maintained enterprise web applications, integrating CRM, DAM, and custom solutions to improve operational efficiency.
Key Accomplishments:
- •Designed and implemented a .NET MVC application for processing new leads into the CRM system, streamlining sales operations.
- •Contributed to a ReactJS CRM dashboard to display and manage business-critical data.
- •Developed DAM frontend/backend tools to manage metadata, detect duplicates, and maintain asset integrity.
K-Rise Systems
Application Developer
Built and optimized features for a .NET development platform and client-facing applications.
Key Accomplishments:
- •Improved search performance by six seconds using Apache Solr, adding intelligent suggestions and spellchecking.
- •Integrated a quote feature for clients, enabling faster and more accurate quote generation.
Innov8tek
Web Development Intern
Developed responsive, client-focused websites using HTML, CSS, JavaScript, and PHP.
Key Accomplishments:
- •Redesigned johnbielskilaw.com for improved user experience and engagement.
Illinois State University
Research Assistant - Social Media Data Collection Program
Created data pipelines to collect and analyze social media content for semantic analysis, leveraging Twitter API, Google Maps API, and Stanford CoreNLP.
Illinois State University
Teaching Assistant
Developed example programs, assisted students with programming assignments, and provided mentorship in coding best practices.