Question 1

Build a Segmented Control

Accepted Answer

**Target Audience:** Beginners preparing for a frontend machine coding round. You need basic React (props, `useState`); controlled components and the radio group pattern are explained here. **Difficulty:** Easy > **How to read this doc:** Every idea is explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. Code excerpts are copied from the runnable solution; the Verified blocks are real output from React 19.3.1

Question 2

Build a Calendar / Date Picker

Accepted Answer

**Target Audience:** Frontend candidates preparing for a machine coding round. Assumes basic React (state, props, effects) and no prior knowledge of calendar math or ARIA. **Difficulty:** Hard > **How to read this doc:** Every idea is explained in plain words first, then tagged with 📌 Interview term: so you also learn the exact vocabulary an interviewer listens for. All output quoted under "Verified" was printed by the real solution, mounted in jsdom with React 19.3.1 in StrictMod

Question 3

Build a Date Picker Calendar with Range Selection

Accepted Answer

**Target Audience:** Candidates who can already build a single-date picker and want the harder range version. Assumes React state and effects. **Difficulty:** Hard > **How to read this doc:** Plain language first, then a 📌 Interview term: callout with the exact vocabulary. Every line under "Verified" was printed by the real solution, mounted with React 19.3.1 in StrictMode inside jsdom and driven by a script, with `TZ=America/New_York` so a daylight saving change sits inside the t

Question 4

Build a Calendar Day View with overlapping events

Accepted Answer

**Target Audience:** Frontend candidates preparing for a machine coding round. Assumes basic React; no algorithms background beyond sorting. **Difficulty:** Hard > **How to read this doc:** Plain words first, then a 📌 Interview term: callout with the exact vocabulary. All "Verified" output was printed by the real code: the layout function run directly in Node 22, and the full component mounted with React 19.3.1 in StrictMode inside jsdom and driven by a script. ## 1. Why This Eve

FRONTEND MACHINE CODINGDECODED.

Easy

Build a Segmented Control

Hard

Build a Calendar / Date Picker

Build a Date Picker Calendar with Range Selection

Build a Calendar Day View with overlapping events