Kinerja karyawan memegang peran kunci bagi kesuksesan perusahaan dan pertumbuhan bisnis. Meski demikian, hasil studi eksplorasi pada perusahaan XYZ menunjukkan adanya penurunan nilai rata-rata Key Performance Index (KPI) pada tahun 2024 meskipun tingkat turnover karyawan menurun. Hal ini menunjukkan bahwa rendahnya niat karyawan untuk keluar perusahaan belum tentu diikuti dengan peningkatan kinerja. Penelitian ini bertujuan untuk menganalisis pengaruh Human Resources Management Practices, Knowledge Management, Talent Management terhadap Employee Performance dengan variabel Employee Development sebagai variabel mediasi pada PT XYZ di Jakarta. Metode yang digunakan adalah penelitian kuantitatif dengan teknik Partial Least Square -Structural Equation Modeling (PLS-SEM). Data dikumpulkan dari 150 responden yang merupakan karyawan tetap perusahaan. Hasil penelitian menunjukkan bahwa Knowledge Management dan Talent Management berpengaruh positif dan signifikan terhadap Employee Development dan Employee Performance, sedangkan variabel Employee Development sebagai variabel mediasi tidak memiliki pengaruh terhadap Employee Performance. / Employee performance plays a key role in the success of a company and business growth. However, the results of an exploratory study at XYZ company showed a decrease in the average value of the Key Performance Index (KPI) in 2024 even though the employee turnover rate decreased. This shows that the low intention of employees to leave the company is not necessarily followed by an increase in performance. This study aims to analyze the effect of Human Resources Management Practices, Knowledge Management, Talent Management on Employee Performance with the Employee Development variable as a mediating variable at PT XYZ in Jakarta. The method used is quantitative research with the Partial Least Square - Structural Equation Modeling (PLS-SEM) technique. Data were collected from 150 respondents who were permanent employees of the company. The results of the study indicate that Knowledge Management and Talent Management have a positive and significant effect on Employee Development and Employee Performance, while the Employee Development variable as a mediating variable has no effect on Employee Performance.