I would not have finished this thesis without the help and support from my professors, my family, and my friends, and my colleagues.First and foremost, I would like to thank my advisor, Prof. Christian Kästner, who is always supportive and patient, provides me guidance, and challenges me. I could have never been here without his countless and significant support for the last 6 years. Through him, I learned the spirit of academics. I will never forget when I was struggling with research, mentoring experiences, and my future plans, he said "I am here to help". I wish I could be a great advisor as Christian in the future.I would like to express my thanks to my 'informal' advisor and collaborator Prof. Bogdan Vasilescu, who is always positive, supportive, and optimistic. From him, I learned the power of passion and perseverance.I would like to say 'thank you' to Prof. Andrzej W ąsowski, who is a terrific collaborator, a mentor, and has been helping me since 2015, and always provides me valuable and helpful feedback.I would like to thank my thesis committee members Prof. James D. Herbsleb and Prof. Laura A. Dabbish. I have learned a great deal from this joyful experience.I am so grateful to Prof. Yingfei Xiong at Peking University. Without Yingfei's support, I would not have the chance to join Carnegie Mellon. Without his help and willing to sacrifice rest time over 2 years to attend my weekly meetings at night, I could not publish my first ICSE paper and get the motivation of pursuing my academic dream.I would like to express my deepest gratitude to Prof. Yuan Rao at Xi'an Jiaotong University who helped me, supported me, guided me for the last 12 years, in Xi'an and in Pittsburgh, as an advisor, a friend and family.I would like to thank my professors in ISR -Prof.