This study investigates the effectiveness of ChatGPT feedback in enhancing the writing skills of Gen Z students, who constitute a significant portion of today's global population. Utilizing a mixed-methods approach, the research explores both quantitative and qualitative aspects of students' interactions with ChatGPT in the context of foreign language education. A quasi-experimental design was employed, involving 110 university students learning English as a Foreign Language (EFL). Through pre-tests, post-tests, questionnaires, and focus group interviews, the impact of ChatGPT feedback on students' writing proficiency was evaluated. Quantitative analysis revealed significant improvements in various aspects of writing, including conciseness, grammar, inclusion of key information, and the use of passive voice, following ChatGPT feedback. Qualitative insights from focus group interviews corroborated these findings, with students expressing positive perceptions of ChatGPT's role in enhancing their writing skills. Overall, the study demonstrates the potential of ChatGPT as an innovative educational tool for fostering writing proficiency among Gen Z students. The findings underscore the importance of integrating AI-driven technologies into language learning processes to meet the evolving needs of contemporary learners.