What is an <iframe> used for?

0-2 years experience

1. 1How would you embed a YouTube video on a product page using an iframe, and which attributes would you set?
2. 2If you forget to set width and height on an iframe, what effect does that have on the page layout?
3. 3What does the sandbox attribute do, and when would you use it for a simple third‑party embed?

2-5 years experience

1. 1Your team added an iframe to load a third‑party payment form, but the form sometimes doesn't resize correctly on mobile. How would you troubleshoot and fix it?
2. 2We need to embed a legacy dashboard that only works in IE11 inside a modern React app using an iframe. What security and communication considerations would you raise?
3. 3Why might an iframe cause the parent page to become unresponsive, and how would you mitigate that issue?

5-8 years experience

1. 1Design a component that loads multiple external widgets via iframes on a high‑traffic dashboard. How would you handle performance, sandboxing, and cross‑origin communication at scale?
2. 2Our security audit flagged that some iframes on the site allow scripts to run. Explain how you would enforce a strict CSP and sandbox policy across the application.
3. 3If we need to replace many iframes with a micro‑frontend architecture, what migration steps would you propose and what trade‑offs should we consider?

8+ years experience

1. 1At an organization level, we are deciding whether to continue using iframes for third‑party integrations or move to a unified API gateway approach. What are the long‑term architectural implications regarding security, performance, and maintainability?
2. 2How would you establish a company‑wide policy and tooling to audit iframe usage, enforce sandbox attributes, and prevent clickjacking across dozens of services?
3. 3When consolidating multiple legacy products that each embed external content via iframes, how would you design a shared platform that standardizes sandboxing, CSP, and monitoring while still allowing team autonomy?