Many developers think that “real-time” is about Websockets, Live data, or instant refreshes on web application dashboards. And although these concepts are closely related to what real-time means, the systems engineering definition is a bit different....

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Real-time systems prioritize predictability over speed, ensuring results arrive before deadlines rather than just being correct. This tutorial builds a soft real-time event monitoring system using Go for deadline-aware backend processing with goroutines and contexts, React with TypeScript for the frontend, and WebSockets for low-latency streaming. The system generates time-sensitive events, enforces deadlines, deliberately drops late work to maintain guarantees, and visualizes latency and missed deadlines. Key concepts include treating time as explicit data, applying backpressure through bounded channels, using requestAnimationFrame for UI updates, and understanding that dropping events under load preserves real-time guarantees better than unbounded buffering.

Real-Time Systems for Web Developers: From Theory to a Live Go + React App