Are applications written in JAVA more secure than .NET Core applications?

Question

For instance, which one would you use to write software for a bank or a telecommunication service company?

Answer 1

In C# (or other .net languages) you can use easy and free tools like Reflector to see ALL of the code written inside an executable or dll.
in Java you have DJ's Decompiler.

You can always try obfuscating the code with the most advanced tools, so this won't be revealed easily, but I'm pretty sure that if the code is worth enough for someone to hack/reverse-engineer, It WILL be, and it's just a matter of time till that happens!

Even with lower level languages like C/C++, if the code is worth it, the people interested will find out how it works.

In the end, it doesn't really matter. If someone is determined, they can always dis-assemble your code and still get the "efficient algorithms". Any code readable by the CPU is readable by a human.