20 Cloudflare Interview Questions and Answers

Cloudflare is a web performance and security company that provides its services to millions of websites. As a result, they are always looking for talented and qualified individuals to join their team. If you are interviewing for a position at Cloudflare, you can expect to be asked questions about your experience with web performance and security. In this article, we will review some of the most common Cloudflare interview questions and how you should answer them.

Cloudflare Interview Questions and Answers

Here are 20 commonly asked Cloudflare interview questions and answers to prepare you for your interview:

1. What is Cloudflare?

Cloudflare is a content delivery network and distributed DNS provider. Cloudflare’s network is one of the largest in the world, handling more than 10% of global internet traffic. Cloudflare’s services can improve website performance, security, and availability.

2. Can you explain how to set up a basic DNS record using Cloudflare?

You can set up a basic DNS record using Cloudflare by creating a Cloudflare account and adding your domain to it. Once your domain is added, you can then create DNS records for it using the Cloudflare interface.

3. How does Cloudflare work?

Cloudflare is a content delivery network and distributed DNS provider. It is designed to speed up the loading of websites and to protect them from attacks. Cloudflare works by sitting between a website and its visitors, routing traffic through its own global network. It also has a number of security features, such as a web application firewall, that can help to protect websites from attacks.

4. Why do you think more and more companies are starting to use Cloudflare as opposed to other CDNs like Akamai or Fastly?

I think there are a few reasons. First, Cloudflare is very easy to set up and use, which is a big plus for companies who are already stretched thin on resources. Second, Cloudflare is very affordable, which is another big selling point for companies who are looking to cut costs. Finally, Cloudflare has a lot of features that other CDNs don’t offer, like DDoS protection and a web application firewall, which can be a big selling point for companies who are looking to increase their security.

5. What is the difference between Proxied vs DNS-only mode in Cloudflare?

Proxied mode will route all traffic through Cloudflare’s network, while DNS-only mode will only route DNS queries through Cloudflare’s network. Proxied mode will provide more protection and performance benefits, but DNS-only mode may be sufficient for some users.

6. In what scenarios would it be a good idea to switch from proxied to DNS only mode in Cloudflare?

If you are not using Cloudflare’s CDN or security features, then it may make sense to switch to DNS only mode in order to improve performance. DNS only mode will bypass Cloudflare’s servers and instead resolve DNS queries directly from your origin server, which can be faster.

7. What are some of the most common uses of Cloudflare?

Cloudflare is most commonly used as a content delivery network (CDN), which means that it can help to improve the speed and performance of websites by caching content and delivering it to users from servers that are closer to their location. Cloudflare can also help to improve website security by offering features like DDoS protection and SSL encryption.

8. What’s the role of DNS records in setting up Cloudflare?

DNS records are used to map domain names to IP addresses, and this is how Cloudflare is able to route traffic to your website. In order to set up Cloudflare, you will need to add a few DNS records to your domain’s configuration. These records will tell Cloudflare where to find your website and how to route traffic to it.

9. Can you give me an example of how Cloudflare can help with security issues?

Cloudflare can help with security issues in a few different ways. One is by providing a web application firewall (WAF) which can help to protect against common web-based attacks. Additionally, Cloudflare can also help to block malicious traffic before it even reaches your website or server, and can also provide DDoS protection to help defend against large-scale attacks.

10. If I’m already running my own load balancer, then why should I use Cloudflare?

Cloudflare can provide a number of benefits even if you are already running your own load balancer. First, Cloudflare can help to protect your site from attacks by filtering out malicious traffic before it ever reaches your server. Additionally, Cloudflare can help to improve your site’s performance by caching content and delivering it to visitors from Cloudflare’s global network of data centers.

11. Can you explain the process used by Cloudflare when serving content off its network?

Cloudflare operates a global network of servers that act as a reverse proxy for websites. When a user visits a website that is powered by Cloudflare, their request is routed through the Cloudflare network. Cloudflare then fetches the requested content from the origin server and serves it back to the user. Cloudflare also provides various security and performance enhancements, such as DDoS protection and caching.

12. What is the significance of Argo on Cloudflare?

Argo is a product from Cloudflare that promises to speed up internet connections by routing traffic through the Cloudflare network. This network is made up of data centers around the world, which means that Argo can route traffic to the closest data center, which should in theory lead to faster speeds.

13. Do you have any experience using Cloudflare Workers for serverless computing tasks?

I do not have any direct experience using Cloudflare Workers, but I am familiar with the concept of serverless computing and believe that Cloudflare Workers could be a good solution for certain types of tasks. For example, if you have a task that needs to be performed on a regular basis but is not time-sensitive, then using a Cloudflare Worker to handle that task could be a good way to save on server resources.

14. Do you know about the new 1.1.1.1 app that Cloudflare recently released?

Yes, the 1.1.1.1 app is a new app from Cloudflare that allows users to route their internet traffic through the Cloudflare network. This can help to improve speeds and security, as well as providing some other benefits.

15. On average, what sort of performance improvements can we expect when using Cloudflare?

Cloudflare can improve your website’s performance in a number of ways. First, it can cache your website’s content so that it doesn’t have to be loaded from your server each time a visitor requests it. This can speed up page load times significantly. Additionally, Cloudflare can optimize your website’s code so that it runs more efficiently, and it can also provide a content delivery network (CDN) so that your content is served from locations closer to your visitors, which can also improve performance. In general, you can expect Cloudflare to improve your website’s performance by 30-50%.

16. What are the advantages and disadvantages of using Cloudflare over Amazon Web Services CloudFront?

The main advantage of Cloudflare is that it offers a free plan which includes many features that are only available on the paid plans of CloudFront. Cloudflare also has a larger network of data centers around the world, which can offer better performance in some cases. The main disadvantage of Cloudflare is that it does not offer the same level of customization and control as CloudFront.

17. What do you understand about Domain Name System (DNS)?

DNS is a system that converts human-readable domain names (like www.example.com) into machine-readable IP addresses (like 192.168.0.1). DNS is what allows us to type in a website’s name instead of its IP address and still be able to connect to it. Cloudflare provides DNS services that can help improve the speed and security of your website.

18. Can you explain what SSL certificates and TLS handshakes are?

SSL certificates are used to encrypt communication between a website and a visitor’s browser. This ensures that any information exchanged between the two is private and cannot be intercepted by third parties. A TLS handshake is the process that occurs when a browser and a website first establish an SSL connection. This handshake involves the exchange of cryptographic keys that will be used to encrypt and decrypt the communication between the two.

19. What are some common types of DDoS attacks?

Some common types of DDoS attacks are SYN floods, UDP floods, and ICMP floods.

20. What’s the difference between HTTP/HTTPS?

HTTP is the protocol that allows communication between different systems on the internet. HTTPS is the secure version of HTTP, which means that all communications between systems are encrypted. This makes it more difficult for third parties to intercept and read data that is being transmitted.