The April 2026 Anthropic Claude Code regression is the canonical case study for vendor capture as a live architectural risk. Three product-layer changes stacked between March 4 and April 20 — reasoning effort silently dropped high→medium, thinking-history cleared every turn, system-prompt updates between tool calls — and AMD's 234,760-tool-call dataset documented read-to-edit ratio dropping 70%, daily costs spiking 125x, BridgeBench accuracy losing 15 points. Critical finding: the raw Anthropic API was unaffected throughout. AMD's response was thin abstraction + provider switch within a week, not a thick-sovereignty migration. Phase 2 cross-provider verification finds zero 25-100 person firms have executed thick sovereignty; the expected-value math is -$700K to -$2M over 5 years. The thin pattern at ~0.25 FTE delivers ~80% of optionality at ~17% of cost. Product.ai today calls Anthropic and OpenAI directly across multiple surfaces with vendor SDK imports in business logic. That makes us non-defensible against the next vendor regression. The candidate ships the constitutional pattern that closes that exposure.
LLMAdapter interface — a small, opinionated surface area: completion, streaming, tool-use, structured-output. Strict typing. Pinned versions. Explicit reasoning effort. System prompts loaded from repo filesLLMAdapter callsLLMAdapterops/scripts/model_router.py — context for the routing layer; the LLMAdapter sits BENEATH itaxioms/Engineering/Engineering Backend Frontier Practice Phase 2 (2026-04-28).md
import anthropic outside the adapter is a failclaude-sonnet-latest or equivalent floating tagsmodel_router.py for routing AND LLMAdapter for the call itself — these are different layers, not duplicatesThe operating principles we work by. If they resonate, the rest of this will land. Open the Codex →
Hireflix, async. Questions are calibrated to this project specifically.
Direct call with the CEO. Strategic alignment and mutual fit. No problem-solving exercise.
1099 contractor agreement, NDA, paid at your stated rate. Day 1 in Santa Monica.
Alpha Team members can take this project without the screen-and-call sequence. Reach out via the Alpha Team channel.