Asynchronous
A communication model where the caller fires off a request and continues without waiting for a response. Essential for non-blocking I/O and event-driven systems.
What is Asynchronous?
A communication model where the caller fires off a request and continues without waiting for a response. Essential for non-blocking I/O and event-driven systems.
Asynchronous is a foundational concept that sits in the Core Fundamentals area of system design. Engineers reach for it whenever they need to reason about real-world trade-offs in that space — not just for textbook correctness, but because real production systems at companies like Netflix, Amazon, and Google make these decisions every day.
If you want to go deeper than this definition — with diagrams, code, and a quiz to lock it in — work through the "Asynchronous" lesson linked below. It walks through the why, the mechanism, the trade-offs, and how the giants actually use it in production.
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See also
Related glossary terms you might want to look up next.
Synchronous
A communication model where the caller waits for the operation to complete before moving on. Simpler to reason about but blocks the thread.
Message Queue
A buffer that stores messages between producers and consumers. Messages are processed one by one, in order. Think of it as a to-do list for your services.
Pub/Sub
A messaging pattern where publishers send messages to topics, and subscribers receive messages from topics they care about. Publishers don't know who's listening.