Pattern: Determinism-Over-Probabilism Kits Are Hardening Agentic Coding Into Engineering
Simon Willison·medium signal
A cluster of new kits (teaql-agent-kit's 'deterministic execution for non-deterministic AI,' spec/DDD-driven scaffolds, growthxai/output's best-practices-baked TS framework) all attack the same problem: free-form vibe coding produces output you can't trust or reproduce. The shared move is to fix the deterministic structure — types, specs, tests, bounded operations — and let the model fill only the gaps. This is the concrete mechanism behind the 'vibe coding → agentic engineering' maturation Simon Willison flagged: guardrails, not just prompts.