Shipping Stock CLIs as Subprocess Instead of Static-Linking SDKs

I'm building yyzTools, which bundles 9 third-party engines (OpenSSL, FFmpeg, ImageMagick, pdfcpu, Aria2, 7-Zip, RapidOCR, Everything...). I chose to spawn them as subprocesses rather than static-link their SDKs. Here's why—and the cost. The conventional approach When your app needs OpenSSL crypto, FFmpeg video processing, ImageMagick image ops—you reach for the SDK. Link libssl, link libav*, link libMagick. One binary, no external deps, fast function calls. It's the textbook answer. I did the opposite. yyzTools ships the stock CLI binaries (openssl.exe, ffmpeg.exe, magick.exe, pdfcpu, aria2c, 7z) and spawns them as subprocesses. The C++ layer is a thin loop: build args → CreateProcess → read stdout → wrap as JSON → return. It doesn't know what -gravity southeast or sm4-cbc means. It just passes the algorithm name through. Why I went this way Upgrades without recompiling This is the big one for a desktop app. OpenSSL ships a CVE, or adds sm2/sm3/sm4 support in 3.x. If you've static-linked, you recompile the whole app, run full regression, re-release, and every user reinstalls. With the subprocess model, I drop in a new openssl.exe. Zero C++ changes. The update is a few-MB delta, not a full reinstall. For a product where users won't tolerate reinstalling for a library bump, this is the deciding factor. No symbol conflicts OpenSSL, zlib, libpng—multiple libraries want to own these symbols. Static linking them all into one binary is a recipe for "which inflate did I just call?" With subprocess CLIs, each tool brings its own dependencies in its own process. No conflict. Transparent supply chain openssl version, ffmpeg -version—auditing which version of each tool is live is trivial. It's an independent binary. Far easier than digging symbols out of a statically-linked blob. Free crash isolation If ffmpeg.exe misbehaves, it exits non-zero and my host wraps that as an error. My main process keeps running. A static-linked bug can take down the whole app. The process boundary