[P] Unix philosophy for ML pipelines: modular, swappable stages with typed contracts

We built an open-source prototype that applies Unix philosophy to retrieval pipelines. Each stage (PII redaction, chunking, dedup, embeddings, eval) is its own plugin with a typed contract, like pipes between Unix tools. The motivation: we swapped a chunker and retrieval got worse, but could not isolate whether it was the chunking or something breaking downstream. With each stage independently swappable, you change one option, re-run eval, and compare precision/recall directly.