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Candidate Caught cheating in interview | lip sync | proxy | [Software Engineering Interview]
A server that serves as a middleman between a client and another server is known as a proxy. The proxy intercepts requests sent to servers by clients and sends them on to the servers. The server then responds to the proxy, who then sends the client the response. This enables the proxy to serve as an intermediary between the client and the server, adding an extra layer of security and privacy.
While using Charles Proxy, I have not personally had anyone attempt to hack my computer, but I would imagine that it would be fairly challenging to do so. If someone were to attempt to hack into your computer while you were using Charles Proxy, you would probably be able to see their attempts and take action to stop them because it allows you to view and edit network traffic.
Although a proxy can be used for a number of purposes, some of the most popular ones are performance enhancement and security. A proxy can boost performance by lowering the number of requests that must be made to the server by caching frequently accessed data. By serving as a mediator between the client and the server and filtering out any potentially harmful requests, a proxy can also offer security.
Web developers can view HTTP and SSL traffic between their computer and the internet using Charles Proxy, a web debugging tool. During your interview, it’s likely that you’ll be questioned about Charles Proxy if you’re applying for a job that requires web development. Knowing how to respond to these inquiries can help you impress the hiring manager by demonstrating your proficiency with the tool. We go over some of the most frequently asked Charles Proxy questions in this article and offer advice on how to respond to them.
For a few reasons, I believe Charles Proxy to be a superior choice for debugging web traffic. First off, it is much more powerful than Fiddler and has a ton more features and options. Second, it is much simpler to set up and use, making it more user-friendly. Last but not least, it receives more updates, which increases the likelihood that it will have the newest features and bug fixes.
Debugging HTTP Connection and Sessions
Charles’ most basic use is to simply run in the background as you test your application in Xcode’s iOS simulator. By doing so, you can actually record the network calls that your application makes and the responses that it receives.
Here are some scenarios where using Charles can be handy:
1. When your app is supposed to fetch data and display it but instead displays an empty screen, the first thing I would check is to see if the data is actually being returned from the network request.
2. If your app sends data to a server to be saved or processed but the outcome isn’t what you expected
3. Your app is calling an API, but you aren’t getting the outcomes you were hoping for.
4. And anything else that has to do with your app making network calls or receiving responses!
Checking that my app is sending the request and parameters I expect it to and that my app is receiving the responses I expect are the first steps I would take in any of the scenarios listed above and others.
When testing your app in the iOS Simulator, you can easily monitor network traffic entering and leaving your app by simply having Charles Proxy open. If Charles Proxy starts logging things when your app isn’t connecting to them, don’t panic. The proxy is keeping an eye on all network traffic coming from any apps you’re using.
Below is a screenshot of what Charles Proxy looks like.
You can see the top level domains that your app is requesting on the left-hand side. To view the actual requests, expand the tree nodes. Choose a request to view its specifics in the pane on the right side.
You can see a summary of that particular network call, including latency, time elapsed, and other information, on the right side. On the right side, near the top, you’ll see tabs. To view the actual data of the network request or response, click “Request” or “Response.”
You can spot problems that could later result in hours of frustration by carefully examining the requests your app makes and the data it returns.
Debugging Network Issues That Only Occur On Devices
Have you ever come across a bug that you couldn’t replicate in the iOS Simulator but later learned could only be reproduced on the real device?
That situation happens to me more frequently than I’d like, but it’s not all that surprising given that, despite how great the Simulator is, its primary purpose is to mimic a real device. The most accurate testing should be done on the actual device(s) and platform(s) that your users will be utilizing your app on.
Charles Proxy can assist you in determining the root cause of network-related bugs that can only be reproduced on the actual iOS device (On a side note, there have been many instances where what I initially believed to NOT be a network bug turned out to be indirectly caused by a network issue). When testing your app on an iOS device, you can see the network calls it makes and the responses it receives directly from Charles on your laptop.
The quick and simple steps to set this up are as follows:
Make sure your laptop and iOS device are connected to the same wireless network in step 1 of 6
Step 2 of 6: To find your IP address on your laptop (OSX), go to System Preferences -> Network.
Step 3 of 6: Next, open Settings and select Wi-Fi on your iOS device.
Step 4 of 6: To view the network’s specifics, click the tiny arrow next to your wireless network.
Step 5 of 6: Choose “Manual” for the proxy settings at the bottom of the screen and enter the IP address you discovered in step 2. Charles Proxy’s default port is 8888.
Step 6 of 6: Now connect your iOS device to the internet using your laptop and the port Charles is watching. In your Charles window, you can see every network request made from your iOS device.
To help you troubleshoot all of those challenging network-related bugs, you can now test your application and see what network calls it makes and what responses it receives.
Charles performs automatic configuration with most browsers, so users do not need to change their browser settings each time they test an application. Hereâs a short guide on how Charles configures web browsers:.
During installation, Charles creates its own distinctive SSL certificates for websites. For both web and mobile browsers, the tester has the option of permanently trusting each certificate issued by Charles. Here is a quick tutorial for configuring automatic trusting for SSL certificates issued to Charles:
For mobile devices running Charles, follow these instructions to turn the HTTP proxy setting on or off: For iPhone:
For mobile browsers, Charles works a little differently. Hereâs a quick breakdown of some of the major differences:.
Charles is compatible with the majority of web and mobile browsers, which is a significant advantage.
FAQ
What is the use of Charles Proxy?
An HTTP debugging proxy server application written in Java is called Charles Web Debugging Proxy. The user can see HTTP, HTTPS, HTTP/2, and enabled TCP port traffic that is accessed from, to, or through the local computer.
What is proxy interview questions?
What is a proxy server? What is the purpose of proxy servers? What are the various types of proxies? How are they deployed? What are some names of proxy servers that are frequently used? What is Squid’s default port and how do I change it?
What is the use of Charles Proxy in testing?
A web debugging tool called Charles Proxy tracks network calls and decrypts web traffic. It helps in understanding the content in your network call. E. g. sending requests to the server, retrieving data from the server, etc. Windows, Android, and iOS devices’ web traffic can be read using this network debugging tool.
What is Charles Proxy for mobile testing?
A developer can view all HTTP, SSL/HTTPS, and reverse proxy traffic between their computer and the Internet using Charles Web Proxy, an HTTP proxy, HTTP monitor, and reverse proxy. Requests, responses, and HTTP headers that include cookie and caching information are all included in this.
