Code Review: As a Beginner

When it comes to the code review, I would choose asynchronous approach other as the reviewer is free of any pressure and skim thoroughly the whole codebase keeping the technical stuff in the mind .This is helpful in understanding the design and working of the project.Reviewing Someone else’s code was bit new experience is to me as I have never did this before.
Though the code was structured well but one key aspect i.e. the output was not getting generating well. Concept of Modularity made it easy for me to jump from one part to another without me feeling lost into it.
The project had no tests whatsoever, making it impossible to verify functionality or catch regressions. And this matters because Without tests, every change becomes a potential breaking change. The developer can't be confident that modifications work correctly, and contributors can't verify their changes don't break existing functionality.
The project lacked any build system (Makefile, CMake, etc.) and had minimal documentation for setup and usage.A project without proper build instructions is essentially unusable by others. It creates a barrier to entry that prevents adoption and contribution.
To perform the review of any project one must have to have wide range of knowledge regarding that language as well as its practical implementation. Insights from this were - Without tests, fundamental issues can go unnoticed and Approaching code from a user's perspective reveals usability issues that developers might overlook.