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PgDog replaced Protobuf serialization with direct C-to-Rust bindings in their PostgreSQL proxy, achieving 5x faster query parsing and 10x faster deparsing. The team forked pg_query.rs and used bindgen with AI-assisted code generation to create 6,000 lines of recursive conversion code that maps C structs directly to Rust. Profiling revealed Protobuf deserialization as the bottleneck, not the Postgres parser itself. The new implementation uses unsafe Rust with recursive algorithms for better CPU cache locality and zero additional memory allocation, resulting in 25% overall performance improvement in pgbench benchmarks.

Replacing Protobuf with Rust to go 5 times faster

This is seriously impressive engineering 👏
Replacing Protobuf with direct C ↔ Rust bindings and validating it byte-for-byte against the existing implementation shows real systems thinking — not just “optimize”, but profile → isolate → redesign → verify. A 5–10x gain in parse/deparse is huge for a proxy layer.
As someone working deeply with performance-sensitive systems, Rust, and AI-assisted workflows, I really appreciate how you constrained the LLM to a machine-verifiable task and wrapped it with strong testing guarantees. That’s exactly how AI should be used in production-grade infra.
Would love to see more about the rewrite engine and sharding internals — this is the kind of low-level optimization work I enjoy building.