If you are developing a large-scale Perl module or a native extension (XS/SPVM), build and test times can become a bottleneck. While we often manually pass -jN to make , I wanted a way to bake parallel execution directly into the Makefile.PL . Today, I want to share a rather "aggressive" hack to achieve parallel builds and tests by injecting logic into WriteMakefile . The Snippet WriteMakefile( macro => { # Force parallel builds MAKEFLAGS => "-j$jobs", # Inject parallel test execution by overriding TEST_VERBOSE # Constraints for Windows shell compatibility (pwsh/cmd.exe): # 1. The entire command is wrapped in double quotes. # 2. No backslashes (\) to avoid escape hell. # 3. No dollar signs ($) to prevent pwsh variable expansion. # 4. No nested parentheses to avoid pwsh tokenization errors. # 5. Only '();. are used for maximum safety. # 6. Minimal symbols to avoid edge cases in shell parsing. 'override TEST_VERBOSE' => "scalar (eval chr(36) .…