LWC Interview Kit: 6 Live-Coding Problems with Samarth Ahuja

The live-coding round is where most Salesforce developer interviews are won or lost. You get 30 to 60 minutes to build a Lightning web component while someone watches, and reading answers does not prepare you for it. Building, against a clock, does.

What you get

- Six problems of the kind product companies set: a star rating, a paged and sortable table, a Kanban board, an OTP resend timer, a three-step contact wizard with Lightning Data Service, and a load-more list over Apex. Each one is timed like the real round, from 30 to 60 minutes.

- Briefs written like an interviewer's, with numbered requirements and no spoilers.

- 35 tests that check your work. Each requirement has its own test, so a failure tells you exactly what is missing. They run in Jest on your laptop: no org needed to practise.

- The finished solutions, all tests passing, deployable to any Developer Edition or scratch org, with a showcase page to try them in Lightning.

- A 23-page Playbook (PDF): how these rounds are marked; for every problem, the approach, the solution explained line by line, the mistakes that cost marks, the follow-up questions interviewers ask with strong answers, and the rubric to score yourself.

- Two real bugs that every test missed and only a real Lightning page exposed, written up as ready-made answers to "tell me about a bug you fixed".

What you will practise

Public properties and events · data down, events up · immutable updates · getters for derived state · the component lifecycle and clean-up · keyboard and screen-reader support · Lightning Data Service and `createRecord` · imperative Apex with loading, empty and error states · guarding against double requests · reading Lightning Data Service errors properly

Who it is for

Salesforce developers with some LWC who are preparing for interviews, or who want to get faster and cleaner at building components. It pairs with the free Lightning Web Components in Depth course on samarthahuja.org, whose last chapter covers the rest of the LWC interview.

What you need

Node.js 18 or later and any code editor. The Salesforce CLI and a free Developer Edition org if you want to see your work on a real page.

How it works

You get an instant download. Everything is self-paced: the tests check your work, and the solutions and the Playbook are there when your time is up. For your own practice; please don't share or resell the kit.