Episode #260
AWS Veteran: How Real Engineering Teams Run Agents
"I need to stop using Opus. This doesn't work." That was Heitor Lessa's conclusion after a refactor cost him 200 million tokens, and it forced him to rebuild the entire agent workflow now used across 1,400 engineers. Heitor spent 11 years at AWS, built Lambda Powertools to 230 billion API calls a week, and in this episode he walks through the full SDLC workflow on screen, from discovery to merge check. In this episode, we cover: The product loop: discovery, whiteboarding, and the /roadmap command Spec-driven development with Open Spec and why vanilla setups fail Three model tiers: SOTA for planning, mid-tier for implementation, cheap models for reviews Merge checks with adversarial reviewers and attestations that catch agents fabricating test results The /retro command: using the Socratic method to make your workflow more deterministic If you're an engineer figuring out how to work with agents at team scale without losing trust in your codebase, this is the workflow to steal. This is also the first Beyond Coding episode with visuals on screen, so let me know what you think of the format. Timestamps: 00:00:00 - The Math Doesn't Add Up 00:00:43 - Amazon Hypergrowth: 11 Years, 8 Different Roles 00:03:29 - Learning From the Trenches as a Technical Account Manager 00:08:38 - Developer Identity and the Birth of Lambda Powertools 00:10:20 - The Hard Parts of Working in Public 00:13:12 - How Powertools Hit 230 Billion API Calls a Week 00:16:42 - Career Advice: Learn Adjacent Roles, Not More Tech 00:19:37 - When Leadership Decisions Don't Make Sense to You 00:23:21 - The Product Loop Starts With Discovery 00:25:22 - From Whiteboard to /roadmap 00:27:37 - Why Humans Plan First and Agents Come Second 00:30:33 - Commands vs Skills Across 32 Different Models 00:33:38 - Adversarial Reviewers on Every Plan 00:36:07 - The Socratic Method, Explained 00:40:29 - Why He Only Takes Paper Notes 00:44:43 - The Five-Line Paper Trick for High-Stakes Meetings 00:48:18 - /new-work: Capturing Scope Creep Without Derailing 00:54:03 - The Dev Loop Begins: Open Spec Explore 00:56:34 - Three Model Tiers: SOTA, Mid, Cheap 00:57:43 - The $5,000/Month Per Engineer Question 00:58:57 - Guardrails vs Autonomy for 1,400 Engineers 01:04:22 - Auto-Sizer: Does This Task Even Need a Spec? 01:07:26 - Decision Fatigue and Why Frameworks Win 01:09:10 - The Plan Phase: Specs, Design, Formal Verification 01:13:07 - The Refactor That Cost 200 Million Tokens 01:15:11 - When Agents Forge Evidence They Ran Your Tests 01:17:27 - Local-First Architecture Explained 01:23:04 - The Apply Phase: Fully Autonomous Loops 01:24:30 - Coding Was Never the Bottleneck 01:26:39 - Why This Workflow Is an Investment 01:27:39 - Decision Logs and the /onboarding Command 01:29:06 - Running Agents Locally With Enterprise Governance 01:32:42 - Hooks: Making Quality Gates Deterministic 01:36:02 - Merge Checks: 15 Adversarial Reviewers Per Change 01:38:30 - /retro: Interviewing Yourself to Improve the Loop 01:43:12 - Trust, Loss of Trust, and Recovery With Agents 01:48:02 - Experience, Scars, and Critical Thinking 01:49:32 - Why Right Now Is the Time to Experiment 01:52:04 - Conviction Comes From Being in the Loop #softwareengineering #aiagents #aws