Q: What is ngTemplateOutlet?

**Target Audience:** Developers who know what an ng-template is and want to render one on demand, pass it data, or hand it to a reusable component. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. View-creation logs, rendered output and type-checking behaviour below were produced on Angular 22.2.3 by compiling with ngc (strict templates) and running in jsdom; the API descriptions were read from the

Question 1

What are template reference variables?

Accepted Answer

**Target Audience:** Anyone preparing for an Angular interview who has written a basic template. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Each "Verified" block comes from compiling the example with ngc and strict templates on Angular 22.2.3 and clicking or typing through it in jsdom. ## 1. Why This Even Matters — A Story First At a busy party you can say "pass me the blue mug" and everyone at the table k

Question 2

How do you configure dynamic base href in Angular builds for different environments?

Accepted Answer

**Target Audience:** Developers deploying Angular apps behind sub-paths, reverse proxies or multi-tenant hosts. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every index.html and bundle detail below comes from running [Angular CLI](/interview-question/what-does-the-angular-cli-provide) 22.2.3 builds on a fresh ng new app; the router behaviour was verified by booting the example in jsdom; URL reso

Question 3

What does the Angular CLI provide?

Accepted Answer

**Target Audience:** Anyone preparing for an Angular interview — no Angular experience needed. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Everything under "Verified" was produced by running Angular CLI 22.2.3 in a sandbox: ng new, ng generate --dry-run, ng serve, ng build, ng test and ng lint, with the real output quoted. ng add an

Question 4

What is the fixture.detectChanges() method in Angular testing, and when should you call it?

Accepted Answer

**Target Audience:** Developers writing or reviewing Angular component tests; assumes you have seen a TestBed spec but not much more. **Difficulty:** Easy to Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts with the vocabulary an interviewer listens for. Every behaviour quoted below was produced by running the spec in the example with Angular CLI 22.2.3 (ng test --watch=false, Vitest + jsdom), in the default zoneles

Question 5

What is the APP_INITIALIZER token and how is it used to load configuration at startup?

Accepted Answer

**Target Audience:** Developers wiring up real deployments, where configuration has to be known before the app can do anything useful. **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 timing logs in section 5 were printed by the example booting on Angular 22.2.3 (with a fake HTTP backend, since no network is involved), and the deprecation fa

Question 6

How do you create a custom validator in reactive forms?

Accepted Answer

**Target Audience:** Developers comfortable with basic reactive forms who need validation rules Angular does not ship. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The statuses and error objects in sections 5 and 6 were printed by the runnable example (compiled with ngc in strict mode, booted in jsdom and typed into by a driver) and by small scripts run against @angular/forms 22.2.3. ## 1. Why

Question 7

What is a directive and what are the types?

Accepted Answer

**Target Audience:** Developers who use components daily and want a clear map of Angular's directive types, and how to write their own. **Difficulty:** Easy to Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The rendered output and event behaviour below were produced on Angular 22.2.3 by compiling the example with ngc (strict templates) and driving it in jsdom; the compiled definitions were read from ngc output an

Question 8

What do @HostListener and @HostBinding do?

Accepted Answer

**Target Audience:** Developers preparing for an Angular interview who have written a directive and want to change or listen to the element it sits on, and who want to know the modern recommended form. **Difficulty:** Easy to Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every "Verified" block was compiled with ngc (strict templates) on Angular 22.2.3 and run; the HTML is the real outerHTML of the elements. Reco

Question 9

How do you optimize initial bundle size using Route Preloading with custom strategies?

Accepted Answer

**Target Audience:** Developers responsible for start-up performance in a real Angular app — assumes [lazy loading](/interview-question/how-does-routing-and-lazy-loading-work-in-angular) and the basics of [preloading strategies](/interview-question/what-are-preloading-strategies). **Difficulty:** Hard > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The bundle tables in section 3 were produced with ng build on Angular CLI 22.2.3. The

Question 10

What is ngTemplateOutlet?

Accepted Answer

**Target Audience:** Developers who know what an ng-template is and want to render one on demand, pass it data, or hand it to a reusable component. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. View-creation logs, rendered output and type-checking behaviour below were produced on Angular 22.2.3 by compiling with ngc (strict templates) and running in jsdom; the API descriptions were read from the

ANGULARDECODED.

Easy

What are template reference variables?

How do you configure dynamic base href in Angular builds for different environments?

What does the Angular CLI provide?

What is the fixture.detectChanges() method in Angular testing, and when should you call it?

Medium

What is the APP_INITIALIZER token and how is it used to load configuration at startup?

How do you create a custom validator in reactive forms?

What is a directive and what are the types?

What do @HostListener and @HostBinding do?

How do you optimize initial bundle size using Route Preloading with custom strategies?

What is ngTemplateOutlet?

How does Dependency Injection work in Angular?

What is the difference between constructor-based DI and the inject() function?

Hard

What is the difference between AOT and JIT compilation?

How do you handle micro-frontend architecture in Angular using Module Federation?

How do you build a custom form control by implementing the ControlValueAccessor interface?

How does compilation work under the hood in Ivy?

What is Zone.js, how does it monkey-patch browser APIs, and how do you build a Zoneless Angular application?

What is Angular Universal / SSR?

What is NgRx?

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