Introduction. Introduction. The integration of digital technologies into the educational system transforms the educational process and stimulates the interest of all its participants in professional development. The research problem lies in the need to adapt the teacher's professional development system to the changing requirements of the digital era. Traditional models undoubtedly have high theoretical and practical significance. However, they are uniform in nature and do not always take into account the individual experience, interests, and preferences, as well as the current needs and career expectations of the teacher. This leads to a narrowing of their educational opportunities and a decrease in the overall quality of education. The purpose of the study is to identify the possibilities and levels of personalization of a teacher's professional development through digital educational platforms (DEP). Materials and methods. The study used theoretical, systematic, and comparative analysis methods. Research results and discussions. The study substantiated the need for a systematic approach to organizing a teacher's professional development through digital platforms and conducted a comparative analysis of their advantages and disadvantages. In conclusion, the article concludes that personalizing a teacher's professional development in a digital environment is not just about updating technology, but also about transitioning from a centralized management model to a flexible, personalized system. The elements of the formula («MIR») for optimizing this system are interconnected. Going through the levels of personalization turns them into an end-to-end creative flow of professional development for teachers.