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Technicalstandard
What's the difference between REST and GraphQL, and when would a PM care?
How to approach it
Explain the difference in how clients ask for data, then tie it to product effects such as mobile speed and how fast teams can ship.
How a strong answer opens
“The main difference is how a client asks for data. With REST you call fixed endpoints that each return a set shape, and with GraphQL the client asks for exactly the fields it needs.”
Outline of a strong answer
Try answering out loud for a few minutes before you open this.
- REST: many fixed endpoints, each returning a set shape of data
- GraphQL: one endpoint where the client asks for exactly the fields it needs
- Product effect: fewer round trips and smaller payloads on slow mobile networks
- Trade-offs: caching is simpler with REST; GraphQL needs care on performance and security
- When a PM cares: public developer APIs, many client apps, or slow screens
- Say you would defer the final choice to engineering but ask about these effects
Where this question usually goes wrong
Declaring one better than the other, or explaining syntax without saying why a PM would care, such as mobile speed and public API design.
Learn the method
APIs and integrations in Module 6, Technical for PMs.
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