They have not hosted it. It's on localhost

I don't, the scraper only scrapes the data on the problem page, you can check out the scraper here , the main test cases need to be added manually.

I'm planning to add main test cases parsing in future though (atleast the ones which are accessible)

Apologies for the late reply,was caught up in something, every compilation request triggers the creation of a docker container which runs alpine linux (which also happens to be one of the most lightweight distro out there with the docker container requiring no more than 8 MB), other than that each container has nothing but the compiler and the code to be executed in it , it compiles, sends out the output and get's destroyed, it all happens in a period of like 2 seconds, so even if someone sends in some code which intends to modify the backend files, they can't, because the container does not have access to it.

Even if they try to do the cpp equivalent of "sudo rm -rf /*", it won't matter, because each container is created fresh on demand and has nothing to with last thing it compiled, You should read more about docker

tldr: The container are a isolated runtime environment which only has access to the request code, they can't even access the internet, one can cause any mayhem they want in there, it won't matter.

we can identify those words and not run the code in the first place maybe

hey, you can check my above reply to the comment if you're wondering about malicious code injection attacks, here are some other things:

As the architecture in the readme,each compilation requeset to the backend has has a rate limiter attached, each IP address is limited to 100 submissions per 15 minutes,and like I said in the previous reply, the submission codes never touch the actual backend, but a docker container.

And each submission has a time limit for 2 seconds, if it doesn't end its execution within that time, the container terminate and a TLE status is sent, so that it doesn't keep running indefinitely.

Basically I'm running this script inside the docker container to evaluate submissions.

Feel free to ask anything :)

You can do the same with LucidChart!

I used draw.io

Hey, I checked it out and it seems like works in a similar way like mine but better

For starters, it also uses docker as a base and then inside the container runs a custom script to code executions, both mine and the one that is used there are similar in various ways(the latter one being a lot more mature) but mine also determines the verdict inside the container which was a stupid idea and easily exploitable as someone mentioned above.

One fix that I'm planning to add is to make the container just spit out the program output and then compare that with the expected output outside the container, that way the container won't need to have access to the verdict and expected output file, making it essentially bulletproof against those attacks

Hi, the backend uses docker API,redis and a file system which can't be hosted on any random host, this needs a proper VM.

he's chinese

Ok

Hi, apologies for late reply, at this point the only thing needed for adding languages is the compiler, do let me know if you have any lightweight docker images for the language you need.

Also, you can contribute here :)