precompiling

Precompiling is the process of producing a pre-made, ready-to-use artifact from source code or data before program execution. The goal is to reduce the amount of work a system must do at runtime, often to improve startup time, performance consistency, or resource usage.

In software development, precompiling can take several forms. One common form is ahead-of-time compilation, where source code is translated into machine code or an intermediate representation before the program runs, in contrast to just-in-time or interpreted execution. Examples include precompiled headers in C and C++, which compile commonly included headers into a single file to shorten subsequent compilations, and runtime environments that generate native images for faster startup, such as in certain .NET or JVM toolchains. Precompilation can also apply to web and template systems, where templates, components, or assets are transformed into optimized runtime representations before deployment, reducing parsing or interpretation at request time.

In practice, precompiling often involves a trade-off. It can improve runtime performance and predictability, but may increase build times, complicate deployment, and require platform-specific artifacts. Properly used, precompilation complements other optimization strategies such as caching, lazy loading, and just-in-time compilation.

Examples across domains include precompiled headers in compiled languages, ahead-of-time compilation or native-image generation in managed runtimes, and precompiled templates or assets in web frameworks. These techniques share the core idea of shifting work from runtime to an earlier phase in the development or deployment pipeline.