Pull CDNs

Lesson in the System Design Roadmap · Stage 9: Content Delivery Networks

Last updated 14 September 2026

What is Pull CDNs?

Pull CDNs grab new content from your server when the first user requests the content. You leave the content on your server and rewrite URLs to point to the CDN. This results in a slower request until the content is cached on the CDN.

A time-to-live (TTL) determines how long content is cached. Pull CDNs minimize storage space on the CDN, but can create redundant traffic if files expire and are pulled before they have actually changed. Sites with heavy traffic work well with pull CDNs, as traffic is spread out more evenly with only recently-requested content remaining on the CDN.

Study this in the interactive course See the whole System Design roadmap

Free resources to learn Pull CDNs

Open sourceIntroduction to CDNs
ArticleThe Differences Between Push And Pull CDNs

Pull CDNs: common questions

Can I learn Pull CDNs in Hindi?

This lesson is written in English. Once you sign in, open it in the interactive course and ask the AI tutor to explain Pull CDNs in Hindi or Hinglish. The tutor answers from this lesson’s own text, so it stays on the syllabus, and it runs on your own Google, OpenAI or Anthropic key.

Is this Pull CDNs tutorial for beginners?

It is lesson 22 of 147 in the free System Design roadmap, in stage 9, Content Delivery Networks. If you are new to System Design, start from stage 1 and come back here in order; if you already know the earlier stages, this lesson stands on its own.