Q: What is the role of NG_VALUE_ACCESSOR in a custom component?

**Target Audience:** Developers who have copied the NG_VALUE_ACCESSOR provider into a component and want to understand each part of it. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every error message below was produced on Angular 22.2.3 by booting a deliberately broken component (compiled with ngc in strict mode, run in jsdom); the selection rules were confirmed in the @angular/forms</cod

Q: How does the @defer block work and what triggers are available?

**Target Audience:** Developers who know what @defer is and need to choose and combine triggers correctly. **Difficulty:** Medium > **How to read this doc:** Ideas are explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. The trigger timeline in section 4 came from running the example on Angular 22.2.3 in both verifier modes (AOT with ngc , and playground JIT) with a script that waits,

Q: Deferrable views — prefetch strategies and dependency isolation with @defer?

**Target Audience:** Developers who already use @defer and want to know what the compiler does with it, and how to control when code is downloaded. **Difficulty:** Hard > **How to read this doc:** Ideas are explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. The compiled code in sections 3 and 4 is real ngc output (see [how Ivy compilation works](/interview-question/how-does-compila

Question 1

How do you handle SSR hydration mismatch errors using ngSkipHydration?

Accepted Answer

**Target Audience:** Developers who hit NG0500 hydration errors from a component they cannot easily rewrite. **Difficulty:** Medium > **How to read this doc:** Ideas are explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. The example was AOT-compiled with ngc, rendered with renderApplication (Angular 22.2.3) and hydrated in jsdom, with and without ngSkipHydration; every

Question 2

What is the role of NG_VALUE_ACCESSOR in a custom component?

Accepted Answer

**Target Audience:** Developers who have copied the NG_VALUE_ACCESSOR provider into a component and want to understand each part of it. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every error message below was produced on Angular 22.2.3 by booting a deliberately broken component (compiled with ngc in strict mode, run in jsdom); the selection rules were confirmed in the @angular/forms

Question 3

How does the @defer block work and what triggers are available?

Accepted Answer

**Target Audience:** Developers who know what @defer is and need to choose and combine triggers correctly. **Difficulty:** Medium > **How to read this doc:** Ideas are explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. The trigger timeline in section 4 came from running the example on Angular 22.2.3 in both verifier modes (AOT with ngc, and playground JIT) with a script that waits,

Question 4

What is the difference between Observables and Promises?

Accepted Answer

**Target Audience:** Anyone preparing for an Angular interview who has used async/await — assumes basic JavaScript, no RxJS required. **Difficulty:** Easy to Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every ordering claim below was produced by running a Node script against RxJS 7.8.2, and the component example was compiled with ngc on Angular 22.2.3 and clicked in jsdom. Execution order is the to

Question 5

How do you test signal components, defer blocks, and new control flow in 2025?

Accepted Answer

**Target Audience:** Developers testing templates written with the modern Angular syntax: signals, @defer, and built-in control flow. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The title says 2025; everything here was run on the current release, Angular 22.2.3 with CLI 22.2.3 (ng test --watch=false, Vitest + jsdom, zoneless). Deep detail on signal inputs, outputs and effects is on its own page

Question 6

How does routing and lazy loading work in Angular?

Accepted Answer

**Target Audience:** Anyone preparing for an Angular interview — assumes you know what a component is, no router experience needed. **Difficulty:** Easy to Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts with the vocabulary an interviewer expects. The navigation logs in section 5 were produced by compiling the example with ngc on Angular 22.2.3 and driving it with Router.navigateByUrl; the bundle sizes in section 6

Question 7

What is content projection and ng-content?

Accepted Answer

**Target Audience:** Developers building reusable wrapper components (cards, callouts, dialogs, layouts) who want to understand how ng-content really works. **Difficulty:** Easy to Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every console log, rendered output and CSS selector quoted below was produced on Angular 22.2.3 by compiling the components with ngc (strict templates) and running them in jsdom. ## 1. Wh

Question 8

What are Deferrable Views (@defer) and how do they work in Angular 17+?

Accepted Answer

**Target Audience:** Angular developers who know components and want to cut the initial bundle without restructuring routes. **Difficulty:** Medium > **How to read this doc:** Ideas are explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. The runnable example was compiled with ngc (strict templates) and also run in playground mode on Angular 22.2.3, then clicked by a script; the error-state and c

Question 9

Deferrable views — prefetch strategies and dependency isolation with @defer?

Accepted Answer

**Target Audience:** Developers who already use @defer and want to know what the compiler does with it, and how to control when code is downloaded. **Difficulty:** Hard > **How to read this doc:** Ideas are explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. The compiled code in sections 3 and 4 is real ngc output (see [how Ivy compilation works](/interview-question/how-does-compila

Question 10

What is the critical render path and how does Angular handle font and style optimization?

Accepted Answer

**Target Audience:** Developers who have seen "render-blocking resources" in Lighthouse and want to know what the browser waits for, and what Angular's build already optimises. **Difficulty:** Medium > **How to read this doc:** Ideas are explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. The index.html snippets were produced by ng build with Angular CLI 22.2.3 on Node 24, once as a

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