What causes layout shift and how do you prevent CLS?
PICTURE THIS: DJANGO MVT
Simple meaning
Media without reserved space, webfonts swapping late, and inserting UI above existing content.
WHY — Performance instead of guessing?
Why interviewers care about Performance:
who only read docs from people who shipped.
and tied to Frontend work.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1Media without reserved space,
webfonts swapping late, and inserting UI above existing content.
- 2I set width and
height or aspect-ratio on images and use font-display strategies.
- 3Skeleton placeholders should match
the final layout size.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
Media without reserved space, webfonts swapping late, and inserting UI above existing content. I set width and height or aspect-ratio on images and use font-display strategies.