The Open Dylan compiler, DFMC, was originally designed in the 1990s to compile Dylan language code targeting the 32-bit Intel x86 platform, or other platforms via portable C. As platforms have evolved since, this approach has been unable to provide efficient code generation for a broader range of target platforms, or to adequately support tools such as debuggers, profilers, and code coverage analyzers. Developing a code generator for Open Dylan that uses the LLVM compiler infrastructure is enabling us to support these goals and modernize our implementation. This work describes the design decisions and engineering trade-offs that have influenced the implementation of the LLVM back-end and its associated run-time support.