Latency measures delay; bandwidth describes transfer capacity. Small-request performance can be dominated by round trips even on a high-capacity link.
Before you start
You should understand clients, servers, IP addresses and ports. Follow a request through name resolution, connection establishment and application exchange. Distinguish protocol guarantees from deployment policy, and use observations from the relevant layer rather than guessing from one browser error message.
The practical goal is to reason through this situation: Several sequential API calls may take longer than one larger response. Read the walkthrough first, then try the interview exercise before opening its answer. The important part is explaining the decision and its consequences, rather than remembering a definition alone.
Step-by-step walkthrough
Step 1: Measure waiting versus transfer
Small requests can spend more time in round trips than sending bytes.
Step 2: Inspect sequential dependencies
Calls waiting for earlier results multiply latency.
Step 3: Optimize the actual bottleneck
Batch, parallelize safely or reduce payload according to evidence.
Worked scenario
Several sequential API calls may take longer than one larger response.
Three sequential calls each spend 100ms waiting and 2ms transferring. Doubling bandwidth barely changes the roughly 306ms interaction. Removing an unnecessary dependency or batching can reduce round trips, but parallel requests are valid only if their data dependencies and server capacity permit it.
Common mistake
Increasing bandwidth does not eliminate handshake or dependency round trips.
Verify the behavior
Compare timing phases before and after the proposed change.
Interview exercise
Improve a slow interaction.
Answer and reasoning
Measure setup, waiting and transfer time, then reduce unnecessary sequencing or payload according to the actual bottleneck.
Continue learning
Compare the scenario with the Networking interview questions and test your understanding with the Networking MCQs. For terminology and implementation details, consult the reference material.