To understand the source code and create your own trading robots in the future, you must know the programming language in which OsEngine is written.
Why C#?
Historically, most trading robots in the Russian Federation are written in this language.
Popular platforms for algorithmic trading in the Russian-speaking internet, ranked from most to least:
1) TsLab
2) OsEngine
3) S #
4) Wealth-Lab
5) Ninja Trader
The 1st, 2nd, and 3rd places are occupied by robot builders that use the C# language.
Therefore, without a doubt, learn C#. In addition to being very convenient for writing robots, you will also be able to find a job as a programmer if you decide at some point to pursue this profession.
Happy algorithm development!