Technical interview guide

Platform APIs & Abstraction Layers

Designing the interface between a platform and the teams using it — what to expose, and what to hide.

Read: 42 min
Practice MCQs: 25
Interview QA: 25
Edition: v3
Editorial status: Reviewed
Relevant for: Platform Engineer

Scope: AWS and Microsoft platform engineering guidance, Google Cloud API Design Guide/AIPs, and Kubernetes API documentation current 2026-08-31.

Interview QA

Treat each question like a live interview question: answer out loud first (structure, assumptions, tradeoffs), then open the model answer to spot gaps and rehearse a tighter follow-up.

Curated: 2026-10-05 · Written: 2026-09-09 · Reviewed: 2026-10-03

QA-1

Choose the right abstraction boundary for a platform capability.

QA-2

Design a platform API for managed databases.

QA-3

Design long-running operation semantics.

QA-4

Design idempotent create and retry behavior.

QA-5

Design a platform API error contract.

QA-6

Design authorization for the platform API.

QA-7

Evolve a stable platform API compatibly.

QA-8

Deprecate a platform API version.

QA-9

Design a provider adapter interface.

QA-10

Represent differences across infrastructure providers.

QA-11

Design a governed escape hatch.

QA-12

Support portal, CLI, and GitOps clients from one API.

QA-13

Design optimistic concurrency and field ownership.

QA-14

Design list, search, and pagination safely.

QA-15

Design deletion semantics for a platform resource.

QA-16

Handle API request timeouts and retries.

QA-17

Design rate limiting and backpressure.

QA-18

Define platform API SLOs and telemetry.

QA-19

Test platform API compatibility.

QA-20

Test provider adapter conformance.

QA-21

Migrate from a provider-shaped API to a domain API.

QA-22

Handle an API outage without harming workloads.

QA-23

Design platform API documentation and SDKs.

QA-24

Govern inner-source platform API providers.

QA-25