Carlos – AWS, React, Node.js

A high-growth global e-commerce brand specializing in inclusive loungewear and shapewear. The project focused on modernizing their storefront by migrating the Shopify Hydrogen frontend to a Remix-based architecture. This wasn't just a code update; it was a strategic move to improve Core Web Vitals and page load speeds for a platform that handles massive traffic spikes during product drops.

• Migrated the Shopify Hydrogen frontend from v1 to v2 using Remix, React.js, and TypeScript, meeting Shopify security and maintainability requirements while delivering noticeable page load improvements and a better UX for a high-traffic e-commerce platform.
• Improved site-wide performance and Core Web Vitals by optimizing React/Remix rendering patterns and frontend architecture, contributing to Lighthouse score gains and improved long-term maintainability.
• Developed, fixed, and enhanced design system components using Storybook, Tailwind CSS, and shared React components, reducing duplicated UI patterns and improving UX consistency and frontend development efficiency within a ~10-engineer team.
• Led the migration from Shopify Scripts (Ruby) to Shopify Checkout Extensibility, rewriting checkout logic in TypeScript-based extensions, eliminating platform deprecation risk, and aligning with Shopify’s modern checkout architecture.
• Integrated Mastercard Dynamic Yield using event tracking, analytics hooks, and A/B testing workflows, enabling data-driven experimentation reflected directly in the live storefront.
• Maintained and evolved a distributed system synchronizing Shopify and Sanity.io, leveraging Node.js, serverless architectures, AWS, and GCP to ensure reliable content and commerce data flow.
• Acted as a senior individual contributor, providing code reviews, architectural input, and best-practice guidance while collaborating with globally distributed teams across the USA, Canada, India, Brazil, and Uruguay.

A U.S.-based fintech platform designed to give workers early access to their earned wages before payday. This Senior Full Stack role focused on building and scaling the internal infrastructure that supports their massive Customer Experience (CX) organization of over 1,000 users. The primary goal was to replace slow, low-code legacy tools with high-performance custom solutions. By moving the CX platform to a modern stack of Next.js, React, and TypeScript, the team reduced page load times from nearly 20 seconds to just ~6 seconds, significantly improving the team's ability to resolve customer issues at scale.

• Built and maintained backend API microservices using C#, .NET 6, REST, and gRPC, improving performance, scalability, reliability, and security for internal platforms supporting a CX organization of 1,000+ users in a FinTech environment with strict security requirements.
• Optimized API performance and data access patterns, reducing response times and lowering operational costs across high-volume internal services.
• Led performance improvements for an internal CX platform built with Next.js, React.js, and TypeScript, replacing low-code platform limitations that caused ~15–20s load times with a custom in-house solution loading in ~6–8s.
• Improved CX workflows and tooling reliability, enabling faster issue resolution and response times for customer-facing teams operating at scale.
• Established a mono-repo architecture using Nx, Node.js, and TypeScript, improving developer velocity, onboarding speed, and code consistency across a ~10-engineer team.
• Developed a shared design system using Mantine.dev and React, reducing duplicated UI work and improving UI consistency and maintainability.
• Integrated Okta SSO and implemented RBAC models, securing internal tools and ensuring controlled, auditable access to sensitive systems.
• Improved CI/CD pipelines using GitHub Actions and Docker, alongside stronger testing practices, increasing deployment confidence, release speed, and system reliability.
• Acted as a senior individual contributor, mentoring engineers and influencing architecture decisions across backend, frontend, and platform layers.

A prominent U.S. automotive marketplace and inventory management platform. This hyper-asynchronous, fully remote role involved developing and evolving a distributed backend system that served as the backbone for multiple client applications and internal microservices. The primary focus was building GraphQL APIs with Apollo, where I strictly followed Test-Driven Development (TDD) to ensure that every new feature was reliable and predictable before going to production.

• Developed and maintained a distributed backend system consumed by multiple client applications and internal microservices.
• Built and evolved GraphQL APIs using Apollo GraphQL, following TDD practices to ensure reliability and predictable behavior.
• Collaborated in a hyper-asynchronous, fully remote environment, contributing to design discussions, testing, and peer code reviews.
• Supported quality assurance efforts through manual testing and review, improving confidence in production releases.

A major fitness and nutrition media provider with millions of users. This role focused on modernizing their high-traffic systems by migrating legacy monolithic REST APIs into AWS serverless microservices. This transition was critical for improving the scalability and reliability of a platform that processes events generated by millions of active frontend clients.

• Developed and maintained distributed backend systems and serverless microservices, processing events generated by high-traffic frontend clients in a consumer-facing platform with millions of users.
• Migrated REST APIs from a monolithic architecture to AWS serverless microservices using AWS Lambda and API Gateway, improving scalability, reliability, and deployment flexibility.
• Designed and implemented a security layer for AWS AppSync using a custom Lambda authorizer, strengthening API access control and request validation.
• Contributed to frontend development using React.js and WordPress, supporting feature delivery across multiple consumer-facing applications.
• Participated in code reviews and manual testing, helping ensure production stability in a fully remote, cross-functional team.

One of the world's largest providers of human resources management software and services. The role involved a specialized, advanced development initiative designed to strengthen integration between development and quality assurance, acting as a cross-functional bridge, leading both manual and automated QA efforts to improve defect detection and release confidence for their complex enterprise platform.

• Joined an advanced, ongoing development initiative to improve delivery efficiency by integrating QA more tightly into the development lifecycle within a fully remote team.
• Led QA efforts across manual and automated testing, improving test coverage, defect detection, and release confidence for a complex enterprise platform.
• Defined and promoted best practices for collaboration between QA and engineering, helping the team achieve more predictable sprint outcomes.
• Contributed to both backend and frontend codebases as needed, supporting feature delivery and issue resolution beyond QA leadership responsibilities.
• Acted as a cross-functional bridge between development and QA, strengthening SDLC adherence and overall delivery quality.

A major fitness and nutrition media provider with millions of users. During this earlier engagement, the role focused on a high-risk migration of legacy REST and SOAP endpoints from a monolithic application to a serverless AWS-based architecture. A major part of the project involved migrating identity-related resources to a third-party authentication solution to improve security and long-term maintainability. The priority was ensuring zero service disruption for the millions of end-users during this digital transformation.

• Led the migration of legacy REST and SOAP endpoints from a monolithic application to a serverless AWS-based microservices architecture, ensuring no service disruption for millions of end users and dozens of dependent client applications;
• Migrated identity-related REST/SOAP resources from a legacy Identity Provider to a third-party authentication solution, improving security, maintainability, and long-term scalability;
• Designed and implemented custom Lambda Authorizers to secure migrated APIs, enforcing authentication and authorization policies across distributed services;
• Developed all migrated services using TDD, increasing reliability and confidence during a high-risk platform migration;
• Produced comprehensive technical documentation, including API specs, architecture diagrams, flow diagrams, and sequence diagrams, improving team alignment and long-term maintainability;
• Performed code reviews, supported QA efforts, and advised on engineering processes, contributing to delivery quality and operational stability in a fully remote team.