What Is a Hop

A Hop is one transfer of information between two separate components in a system.

Every time an event:

• Leaves one component
• And enters another

That’s one Hop.

It doesn’t matter if it’s:

• A different process
• A different service
• A different machine
• Or an infrastructure component in between

If the information crosses a boundary point - that’s a Hop.

Why Hop Is an Important Concept

Because a Hop isn’t computation - it’s movement. And movement in systems costs time.

In every Hop, at least one of the following happens:

• Data copying
• Serialization / deserialization
• Queuing and waiting
• Rescheduling of work
• Passing through the network

Even if each such step is “short” - they accumulate.

A Simple Example

Suppose an event travels like this:

• Service A creates an event
• The event passes to a Broker
• The Broker forwards it to Service B

That’s already two Hops:

A → Broker Broker → B

If there’s another Broker, another queue, or another processing layer - another Hop is added.

Why This Is Critical in Event-Driven Systems

In Event-driven systems:

• Events tend to pass through many Hops
• Every Hop adds Latency
• And the time doesn’t sit in one clear place

That’s why a system can feel “slow” even without heavy computation and even without a single bottleneck.

The time simply gets spread out along the way.