In a world where digital experiences are everything, slow-loading pages are a surefire way to lose user engagement. Modern web applications rely heavily on dynamic data, but how we fetch and render that data can make or break the user experience. This blog post will explore the best practices and new approaches for improving page load times and enhancing Core Web Vitals through the lens of “Streams Not Waterfalls,” a concept discussed by Smart Data software engineer Dev Agrawal during a recent “Lunch and Learn” event (Link to the talk here: Virtual Recording Link), we’ll dive into the challenges of modern web development, the issues with traditional approaches, and the emerging solutions.
Understanding the Basics: Single-Page Applications and Their Challenges
Single-page applications (SPAs) have become the go-to for building modern web experiences using frameworks like React and Angular. They allow for snappy, immediate interactions without the jarring full-page reloads. But there’s a catch: the dreaded initial load time.The browser requests the HTML, and then a massive JavaScript bundle needs to load before the page is functional. This is where techniques like code splitting and lazy loading can help, but they only go so far. Even when we split our bundles into smaller chunks, traditional SPAs still face a common problem—the waterfall effect.
Why Waterfalls Are Bad News for Performance
Ever heard of the “waterfall” issue in web development? It’s when data-fetching operations happen sequentially, one after the other, causing major slowdowns. In SPAs, components often wait for each other’s data to load, which results in those frustratingly long wait times.To illustrate this problem, I demoed an e-commerce page using Remix and React Query. Each component fetched its own data independently—great for flexibility, but awful for performance. I’m calling this phenomenon “Spinnageddon,” where endless loading spinners drive users away.
From Waterfalls to Streaming: Changing the Flow
So, how do we fix this? The answer lies in abandoning the traditional waterfall pattern and moving towards streaming and smarter data-fetching strategies.1. Data Hoisting: The Pros and ConsOne way to tackle the waterfall issue is data hoisting, moving the data-fetching process up to a higher-level component like a route loader or server-side function. This allows for parallel fetching of data, reducing load times significantly. But beware—hoisting can make the codebase brittle and error-prone, especially when you’re dealing with a large application.2. The GraphQL & Relay SolutionGraphQL, especially when combined with Relay, can help avoid the pitfalls of hoisting. With GraphQL, you define data queries inside components, and Relay optimizes the fetching process. This keeps the composability of your code intact while improving load times—a win-win.
Server-Side Rendering (SSR): A Powerful Ally
If GraphQL isn’t an option, server-side rendering (SSR) is another great way to optimize page load times. SSR tackles the waterfall problem by shifting data-fetching from the client to the server, sending fully rendered HTML to the browser before JavaScript loads.This doesn’t just make your website faster; it’s also great for SEO. Search engines love content that’s rendered server-side. But we can do even better by incorporating streaming.Streaming HTML: Why It WorksStreaming lets you send HTML to the browser in chunks as data becomes available. This allows users to start interacting with visible content while the rest of the page continues to load in the background. It’s like getting a sneak peek of the movie while it’s still buffering—faster Time to First Byte (TTFB) and early interactivity!
Core Web Vitals: The Metrics That Matter
In the web performance world, Core Web Vitals are crucial metrics that can make or break the user experience:Largest Contentful Paint (LCP): Measures loading performance. You want to ensure that the largest visible element (like images or big text blocks) appears quickly.How to Improve: Use lazy loading for offscreen elements, preload critical assets, and implement SSR with streaming.First Input Delay (FID): Tracks how quickly the page responds to a user’s first interaction (e.g., clicking a button).How to Improve: Prioritize main-thread work by splitting JavaScript code into smaller pieces and deferring non-essential third-party scripts.Cumulative Layout Shift (CLS): Measures visual stability—nothing’s worse than content shifting as you’re about to click.How to Improve: Define explicit dimensions for images, avoid inserting new content above the fold, and use placeholders to prevent unexpected shifts.
React to the Rescue: Modern Tools for Modern Problems
React has come a long way in tackling performance challenges. Here are a few tools and techniques I’ve been excited about:1. Concurrent RenderingReact’s concurrent rendering capabilities allow it to prioritize tasks based on importance, preventing lower-priority updates (like animations) from blocking essential user interactions. This directly improves metrics like FID, leading to smoother user experiences.2. React Server Components: The Future is HereReact Server Components offer a hybrid model that combines the best of SPAs and traditional multi-page apps (MPAs). They allow server-side data fetching while maintaining component-based flexibility, improving both initial load times and developer experience.Data Fetching on the Server: Fetch data server-side for faster initial render.Suspense for Data Fetching: Utilize React’s Suspense to handle asynchronous data-fetching gracefully, displaying fallback UI during loading.
Real-World Examples: Streaming Success Stories
Streaming and other optimization techniques have already been making waves in real-world applications:E-Commerce: Progressive loading of images and product details allows customers to browse while data is fetched, reducing bounce rates and increasing conversion rates.Media Platforms: Streaming enables users to start viewing content before the entire video or media file buffers, resulting in happier viewers.SPAs: Streaming and Suspense transform how data is managed, leading to faster interaction times and more engaged users.
Final Thoughts: Balancing Speed and Flexibility
Web performance is all about trade-offs. Balancing the need for speed with code flexibility and composability is a constant challenge:From Waterfalls to Streaming: Shift to streaming for faster user interactions.Prioritize Core Web Vitals: LCP, FID, and CLS should be at the forefront of your optimization efforts.Leverage React’s Latest Features: Tools like concurrent rendering, Suspense, and React Server Components can make a massive difference in performance.Modern web development is always evolving, and it’s up to us as developers to push the boundaries. Frameworks like Next.js, Remix, and tools like GraphQL offer powerful solutions to make the web faster and more engaging. And with innovations like React Server Components, the future of web development is brighter than ever.
About Smart DataAt Smart Data, we specialize in crafting custom web and mobile applications that address the unique challenges faced by businesses today. Our team has extensive experience in delivering integrated, cloud-optimized solutions across a wide range of industries, from e-commerce to field service and B2B payments. With a focus on innovation and tailored solutions, we combine UX/UI expertise, data engineering, and advanced technologies like ML and AI to create applications that improve operations, reduce costs, and drive business growth. Contact us today to learn more about our services. We look forward to helping you take your software development process to the next level!
