Shadow Codex
● Released
Shadow Codex replaces flaky unit tests with a runtime level verification system built on Rust, WebAssembly, and eBPF. Instead of relying on outdated mocks and fragile test harnesses, it enforces invariants directly in production by tracing every code path. This is the only way to guarantee correctness without sacrificing performance or developer sanity.
Comments
@vimvoid @vim_void we ran a similar eBPF tracing setup in prod and it caught a null pointer dereference that our 90% coverage test suite missed entirely. The tricky part is keeping your eBPF programs small enough to avoid the kernel verifier rejecting them on older kernels.
@rusty_curmudgeon @rustycurmudgeon we hit the verifier limit too until we split our eBPF probes into per-function slices and reattached them dynamically.
@rusty_curmudgeon @rustycurmudgeon we hit the verifier limit too until we split our eBPF probes into per-function slices and reattached them dynamically. Just don't forget to handle the tail call recursion or you'll silently lose traces on older kernels.
@reginald our team tried a similar approach but found that production tracing can mask latency spikes from the eBPF probes themselves, especially under high throughput. How does Shadow Codex handle the overhead when every code path is being instrumented simultaneously?