Design a Pinterest-style masonry grid
PremiumFrontend systemEasy
- Masonry layout
- Column balancing
- CLS
Quick answer
This frontend system interview question asks you to design a Pinterest-style masonry grid. Aim for a design that loads fast, stays responsive and is easy to maintain, then explain components, state, data fetching and trade-offs. Interviewers want to see how you structure the interface, manage state and keep the experience fast.
The problem
Design a Pinterest-style masonry grid of image cards that share a column width but differ in height. The hard part is placing each card in the shortest column without gaps, reserving space so images never shift the layout, and staying smooth with 1,000 cards loaded.
Card heights come from each image's aspect ratio. The grid adds more cards as the user scrolls, re-flows when the window is resized or the device is rotated, and opens a card in a detail view with a back navigation that returns to the same place.
What must a Pinterest-style masonry grid do?
- Layout: 2 columns on phones, 3 to 5 on tablets and desktops, with a fixed gutter; each new card goes to the shortest column.
- Infinite scroll: Load the next page before the user reaches the bottom; show skeleton cards while loading.
How well must it do it?
- Smoothness: 60 fps scrolling with 1,000 cards loaded on a mid-range phone.
- Layout shift: Cumulative Layout Shift under 0.1 on the page.
What scale should you design for?
Use these numbers in your estimates.
The scale numbers unlock with this questionUnlock
Key concepts
- Masonry layout
- Column balancing
- CLS
- Aspect ratio placeholders
- ResizeObserver
- Infinite scroll
How you’ll practise
- Requirements
- Components
- State and data
- Network and caching
- Performance and accessibility
- Wrap-up
Lala, personalized to you, gives a hint when you ask and reviews your design when you are ready.
What do interviewers look for?
In any frontend system design round.
- Starts from the user flows and the screens
- Splits the interface into clear components
- Decides where state lives and how it stays in sync
- Plans data fetching, caching and loading states
- Covers performance, accessibility and error states
- Explains how the design holds up on slow networks and small screens
Questions people ask about this interview question
- Which design type is this question?
- It is a frontend system question. You design a Pinterest-style masonry grid and explain your choices the way you would in an interview.
- Is this question asked at entry level?
- It is marked Easy, so it suits engineers who are new to frontend system interviews. It is also a good warm-up before harder questions.
- What should I cover first?
- Start with the main user flows, the screens and the data each one needs. Agree on scope with the interviewer before you design anything.
- Can I practise it for free?
- It is a premium question. Sign up and unlock it once for 10 credits; it then stays unlocked. When you finish, Lala, your personalized AI mentor, can review your design for 30 credits.
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Updated · Written by the SevyDevy team