Brenn reached out via LinkedIn to share his experience with AI-driven software development and his new book, The Delivery Gap. Romain read a copy during a business trip and found it deeply aligned with how he guides customers through their AI transformation — and discovered a few new angles worth exploring, including a convergence on cost tracking that maps directly to Amazon's internal cost to serve software metric. In this episode, Brenn — Senior Manager at Delivery Hero (one of the world's largest food delivery companies, operating in 65 countries) — breaks down why most companies fail to see returns from AI coding tools despite individual developers feeling more productive. The core insight: generating code 10x faster means nothing if your verification infrastructure can't keep up. You're just driving 10x faster into a wall. Key takeaways: • The 96% waste problem — If you generate 100 PRs and only 4 make it to production and stay there, the other 96 are waste. Measuring PRs created is meaningless; measure what ships and survives. • The verification triangle — Your delivery speed is governed by verification infrastructure, not generation speed. Banks can't release faster than they can audit. Find your constraint — that's where investment should go, not more coding tools. • Cost per accepted change — Total token costs + human time for all PRs, divided by changes that reach production and stay there. This single metric reveals where waste accumulates and aligns with Amazon's cost to serve software model. • Specs as alignment documents, not source code — Specs align humans and AI on intent and why, not for deterministic code generation. The same spec produces different software each time. Focus on why; let the AI document the what. • Keep agents small and focused — Every MCP server re-injected into context is a cost multiplier per turn. The smallest, tightest, most precisely aimed agent outperforms a Swiss Army knife agent on both cost and accuracy. Apply cost per accepted action to measure agentic ROI.

With Brenn, Senior Manager at Delivery Hero & Author of The Delivery Gap