Technical interview guide

Webhooks & Asynchronous API Integration

Handling work that can't complete within a single request/response cycle — inbound webhooks and long-running async job APIs.

Read: 23 min
Practice MCQs: 25
Interview QA: 25
Edition: v3
Editorial status: Reviewed
Relevant for: AI EngineerAgentic AI EngineerBackend EngineerBlockchain DeveloperCloud ArchitectCybersecurity EngineerData ArchitectData EngineerDevOps EngineerForward Deployed Engineer (FDE)Frontend EngineerFull-Stack DeveloperIdentity and Access Management (IAM) EngineerMachine Learning EngineerPlatform EngineerSecurity ArchitectSite Reliability EngineerSoftware EngineerSolutions ArchitectTechnical Product Manager

Scope: HTTP Semantics RFC 9110 and OpenAPI Specification 3.2.

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: 2026-10-02 · Written: 2026-10-02 · Reviewed: 2026-10-03

QA-1

What is a webhook, and what makes them harder than they look?

QA-2

How would you design webhook delivery to be reliable?

QA-3

How would you secure webhooks, in both directions?

QA-4

How should a webhook receiver be implemented?

QA-5

Compare webhooks, polling, server-sent events and WebSockets.

QA-6

How would you handle webhook event ordering?

QA-7

What should a webhook payload contain?

QA-8

A consumer says they are missing webhook events. How do you investigate?

QA-9

How would you handle a webhook endpoint that is persistently failing?

QA-10

How would you test a webhook integration, from both sides?

QA-11

What does a good webhook developer experience look like?

QA-12

When would you choose webhooks over a message queue, and vice versa?

QA-13

How would you evolve a webhook event schema without breaking consumers?

QA-14

What monitoring would you put on a webhook delivery system?

QA-15

How would you support replay of webhook events?

QA-16

What are the most common correctness mistakes in webhook consumer implementations, and how do you avoid them?

QA-17

How do webhooks interact with the sender's own transaction boundaries?

QA-18

How would you decide which events a webhook system should emit?

QA-19

What happens when a webhook receiver is much slower than the event rate?

QA-20

How would you introduce webhooks to an existing API that only supports polling?

QA-21

Explain the failure modes a webhook consumer should plan for.

QA-22

How would you handle secrets and signature verification for many webhook consumers?

QA-23

What is the operational cost of running a webhook system, and how do you reduce it?

QA-24

What delivery guarantee does a webhook system actually provide, and what does each clause of that guarantee force the consumer to build?

QA-25