Context: Writing Clean Code understandable by other collaborators has become crucial to enhancing collaboration and productivity. However, very little is known regarding whether developers agree with Clean Code Principles and how they apply them in practice.\\ Objectives: In this work, we investigated how developers perceive Clean Code principles, whether they believe that helps reading, understanding, reusing, and modifying Clean Code, and how they deal with Clean Code in practice. Methods: We conducted a Systematic Literature Review in which we considered 771 research papers to collect Clean Code principles and a survey among 39 practitioners, some of them with more than 20 years of development experience.\\ Results: So far, the results show a shared agreement with Clean Code principles and its potential benefits. They also show that developers tend to write messy code to be refactored later.