Novice teachers' professional contexts may have important implications for their effectiveness, development, and retention. However, descriptions of these contexts suffer from data limitations, resulting in unidimensional or vague characterizations. Using 10 years of administrative data from the Los Angeles Unified School District, we describe patterns of new teacher sorting using 27 context measures organized along three distinct dimensions -- intensity of instructional responsibilities, homophily, and colleague qualifications -- and use school-level survey data to measure a fourth dimension (professional culture). Relative to more experienced teachers, novice teachers have placements that are more challenging along the first three dimensions, and composite measures are differentially predictive of teachers' outcomes. This suggests that policymakers should consider placements to better retain and develop novice teachers.