# Former Nike and Walmart engineer Jack Herrington on building smarter APIs — a Postman case study. Source: https://www.youtube.com/watch?v=dm0DijolHnY Recap page: https://rapidrecap.app/video/dm0DijolHnY Generated: 2026-01-25T20:04:14.616+00:00 --- ## Quick Overview Jack Herrington, former Principal Software Engineer at Nike and Walmart, leverages tools like Postman, TanStack Query, and an MCP (Mock Context Protocol) server system to significantly improve developer productivity by enabling asynchronous testing and collaboration without relying on complex, hard-to-test systems of record. **Key Points:** - Jack Herrington's full-time job transitioned from being a Principal Engineer at large companies like Nike and Walmart to being a YouTuber and content creator focused on building things for people. - Herrington advocates for using tools that facilitate asynchronous communication between developers and systems, specifically citing the need to test against APIs without relying on complex systems of record. - The core problem solved is the inability to easily test APIs when they are tightly coupled to large, difficult-to-test systems, which slows down productivity. - Herrington demonstrates using Postman, TanStack, and an MCP (Mock Context Protocol) server system to create a single source of truth for API documentation and testing. - The key benefit of this approach is allowing developers to mock specific API versions and collaborate on them using simple drag-and-drop functionality, which is described as a 'huge unlock' and 'game changer'. - The video shows Herrington explaining the architecture with a diagram illustrating the separation between the Server (Route, Make API Calls, Render React/HTML) and the Client (Render HTML, Store State Data, Parse JS Bundle, Rehydrate React App, Reconcile with Existing DOM). ![Screenshot at 00:28: Jack Herrington introduces the concept by showing the Postman website promoting 'AI needs context. APIs deliver it,' setting the stage for discussing modern API development tools and workflows.](https://ss.rapidrecap.app/screens/dm0DijolHnY/00-00-28.jpg) **Context:** Jack Herrington, identified as a Principal Software Engineer formerly working at Nike and Walmart, discusses his shift toward content creation, primarily on YouTube under the channel 'Blue Collar Coder,' where he focuses on building software that helps people. The discussion centers on the challenges of API development, particularly in large organizations where testing against live, complex systems of record is cumbersome, leading him to champion tools that enable better mocking and asynchronous workflows. ## Detailed Analysis Jack Herrington explains that his career goal, spanning roles at Nike, Walmart, and various startups, has always been to build things that make people happy, focusing on the 'how you use a computer to do cool stuff' rather than algorithms. He highlights a major challenge in large companies: the difficulty of testing APIs because they are often tied to massive, slow systems of record, leading to multiple, hard-to-test versions of the API documentation. To overcome this, Herrington advocates for using a combination of tools, specifically mentioning Postman, TanStack Query, and an MCP (Mock Context Protocol) server system, which he claims is a 'game changer.' The MCP system allows developers to create a single source of truth for documentation and enables them to mock specific API releases, allowing for asynchronous collaboration and testing against the mock server instead of the real, complex backend. This ability to quickly create and test against mock services dramatically accelerates development and testing cycles, especially in large enterprise environments. ### Career Background - Full-time YouTuber/Content Creator - Former Principal Engineer at Nike and Walmart - Focus on building useful software for people. ### API Development Challenges - Large companies have systems of record that are difficult to test against - This creates friction and slows down development when testing against live APIs. ### Solution Introduction - Using Postman, TanStack, and an MCP (Mock Context Protocol) server system - The goal is to enable developers to communicate asynchronously without relying on slow, complex systems. ### Technical Architecture - Diagram shows Server components (Route, API Calls, Rendering) and Client components (Rehydration, Interactivity) - The MCP server acts as a mock layer. ### Key Benefits - Enables creating mock API services using simple drag-and-drop methods - Allows developers to pin specific API versions for testing - Vastly improves documentation as a single source of truth and speeds up testing. ### Personal Motivation - Driven by making people happy and building things, not just algorithms. ![Screenshot at 00:01: Establishing shot of a dense, sunlit forest, setting the outdoor, nature-focused theme contrasting with the technical discussion.](https://ss.rapidrecap.app/screens/dm0DijolHnY/00-00-01.jpg) ![Screenshot at 00:30: Diagram illustrating the flow between the Server and Client components of an application, emphasizing the need to 'MAKE IT WORK'.](https://ss.rapidrecap.app/screens/dm0DijolHnY/00-00-30.jpg) ![Screenshot at 00:37: Claymation figures representing developers interacting around a laptop displaying code, symbolizing the development process.](https://ss.rapidrecap.app/screens/dm0DijolHnY/00-00-37.jpg) ![Screenshot at 01:35: Jack Herrington putting on headphones near a microphone, indicating the transition to recording or deep technical work.](https://ss.rapidrecap.app/screens/dm0DijolHnY/00-01-35.jpg) ![Screenshot at 02:22: Two developers collaborating closely over a monitor displaying documentation, illustrating the collaboration aspect Postman enables.](https://ss.rapidrecap.app/screens/dm0DijolHnY/00-02-22.jpg)