Code Editor in Python or C# or Flutter

I am looking for a code editor built in Python, C# or Flutter programming language with autocompletion feature and intended for commercial use. The ideal candidate will possess a comprehensive understanding of the chosen language and be able to provide robust, well-functional code editor. They should also understand the user experience (UX) requirements and be competent in software development techniques such as syntax highlighting, debugging, autocompletion and other features that will provide a rich user experience. The coding standards must meet customer-driven expectations and the code should be prepared to be released to the clients in the shortest possible time. The ideal candidate should provide not only the necessary technical expertise but also have considerable experience in the area of software development.