Carlos OrtizSenior Full Stack Engineer

Built an interactive platform that simulates real React technical interviews, where developers solve timed coding challenges in TypeScript with instant test-based feedback and a realistic development environment.

• Developed a full-stack Next.js application that allows users to solve React challenges under timed conditions, emulating real interview scenarios.
• Implemented a secure testing server that receives challenge code submissions, runs automated tests in isolation, and returns structured feedback to the client.
• Integrated the Monaco Editor with TypeScript support and a Vim keybinding layer for an authentic developer experience.
• Used Sandpack to dynamically render React components in-browser, enabling instant visual previews of user solutions.
• Designed and managed a PostgreSQL database using Drizzle ORM to store users, challenge attempts, results, and progress history.
• Created a custom API layer for handling submissions, timing, and test evaluation, ensuring performance and sandboxed isolation.
• Built a clean, responsive interface using Tailwind CSS and shadcn/ui components for consistency and accessibility across devices.
• Implemented secure authentication, session handling, and middleware for route protection and challenge access control.
• Optimized the build and deployment process for Vercel, including the integration of a dedicated runtime for test execution and challenge rendering.

FlowArchitect was an early-stage startup building open-source tools to design and orchestrate AI workflows. As Lead Frontend Engineer, I owned the frontend architecture of its Design Workflow product, a visual editor built on React and Rete.js that translated node-based flows into the Common Workflow Language. I defined the technical roadmap, led the frontend team, and established the testing foundation with Vitest and Playwright.

• Led the development of frontend architecture for AI-driven workflow applications.
• Defined the technical roadmap and architecture for the Design Workflow project.
• Designed and implemented scalable, maintainable, and reusable UI components using React.
• Defined workflows that could be translated into the Common Workflow Language.
• Collaborated with cross-functional teams to translate business requirements into intuitive and efficient user interfaces.
• Integrated APIs and AI tools seamlessly into frontend workflows to deliver intelligent application solutions.
• Led developers and provided guidance to team members, fostering a collaborative and high-performing engineering culture.
• Conducted code reviews to maintain high standards of quality and technical excellence.
• Implemented automated testing strategies to ensure the reliability and robustness of frontend components.

At Urchin Labs I built one of the early ChatGPT-powered customer service assistants (Apr 2023), when LangChain-style frameworks did not yet exist and PHP offered no AI ecosystem. With no libraries to lean on, I implemented the entire retrieval pipeline by hand, document chunking, OpenAI embeddings, Pinecone vector search, and context assembly, and wired it into WooCommerce through a custom WordPress plugin. When the startup did not secure follow-on funding, I took full ownership: I documented the specifications and launched it independently as MainGPT, an AI chat assistant for online businesses with semantic search and contextual memory.

• Implemented an end-to-end retrieval-augmented (RAG) pipeline from scratch in PHP, document chunking, text embeddings, Pinecone vector search, and context assembly, with no existing framework or library to build on.
• Engineered prompts and conversational memory manually to keep answers grounded in each store's content and products.
• Designed and developed AI-driven chat interfaces using React and Vue.js on top of the OpenAI (ChatGPT) API, with semantic search and tailored customer responses.
• Built a custom WordPress plugin for seamless AI assistant integration into existing business websites, including WooCommerce support.
• Built the core website using a headless WordPress setup with Next.js and GraphQL, delivering a modern, fast, and interactive user experience.
• Set up CI/CD pipelines with GitHub Actions to automate testing and deployment.
• Conducted extensive testing with Vitest and Playwright to ensure reliability, scalability, and performance across plugin and website.
• Took full ownership when the startup ceased operations, completed development independently, documented technical specifications, and launched the product as MainGPT.

Network Rail is the owner and infrastructure manager of most of the railway network in Great Britain. As a public sector body, accessibility and compliance were core requirements. I worked on several projects for the company's internal systems, primarily leading the development of the new corporate website and providing guidance to other teams and agencies. In 2018, before component libraries and design systems became standard practice, I introduced a shared Storybook-based design system, a deliberate bet that it would cut duplicated work and prevent inconsistencies as more teams and external agencies built on the platform.

• Designed the architecture, development, and maintenance of the company's corporate website.
• Led the design and implementation of new features and functionality to enhance the user experience.
• Defined standards and tech stack in collaboration with other agencies and teams.
• Created custom Gutenberg blocks based on Advanced Custom Fields and Vue.js
• Introduced a shared, Storybook-based design system in 2018, before component-driven tooling became mainstream, as a deliberate investment in future velocity and fewer UI errors, not to follow a trend.
• Standardised UI across internal teams and external agencies by documenting and maintaining the system, so new features reused existing primitives instead of duplicating work.
• Used Storybook with Chromatic for visual regression testing, catching UI inconsistencies before release.
• Created single-page applications and other microsites based on Vue.js
• Monitored website performance and took appropriate action to ensure optimal performance.
• Ensured WCAG 2.1 AA accessibility compliance across the corporate website and all microsites, baking keyboard navigation, screen reader support, and ARIA best practices into the design system so they were enforced by default.

Klood was a digital marketing agency based in Milton Keynes that specializes in inbound marketing.

• Met with clients to discuss website designs and functionality.
• Created custom plugins, themes, and functions for WordPress websites.
• Tested frontend code in multiple browsers to ensure cross-browser compatibility.
• Worked with multiple APIs and RESTful Services.
• Configured Cloudflare for client sites, including DNS records and caching/CDN settings.
• Built reusable code and libraries for future use.
• Optimized pages for page speed using Google PageSpeed (API) for Apache to achieve higher rankings on Search Engines (SEM).
• Frontend development using the latest HTML5 and CSS3 techniques, enhanced by jQuery to enable optimum user experience throughout the websites.
• Worked in Agile methodology.