Spec Drivent Development

Spec-Driven Development is not a revival of V model or Waterfall, it's a new approach to give enough context to a coding agent (LLM) for a small scope task.

Presentation given at "AI in the SDLC - rethinking how we build" event in Geneva

Also see my blog post.

Transcript

1. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 1 © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. Jerome Van Der Linden Sr AI Engineer, DevTx Spec Driven Development
2. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 2 The “prompt-and-pray” loop aka Vibe Coding
3. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 3 Coding agents need more context
4. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 4 What is Spec-Driven Development? Set of Ar)facts Document requirements, design decisions, and current progress in a consistent way. Structured Workflow Plan first, then build. Build the right thing the first <me.
5. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 5 WHAT IS SPEC-DRIVEN DEVELOPMENT? Set of Artifacts Document requirements, design decisions, and current progress in a consistent way. Requirements Design Tasks
6. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 6 What is Spec-Driven Development? Set of Ar)facts Document requirements, design decisions, and current progress in a consistent way. Structured Workflow Plan first, then build. Build the right thing the first time.
7. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 7 WHAT IS SPEC-DRIVEN DEVELOPMENT? Structured Workflow Plan first, then build. Build the right thing the first time. Create Spec Define Requirements Happy? Draft Design Happy? Generate Tasks Happy? Execute
8. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 8 DEMO
9. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 9 Spec-Driven Development in the SDLC Requirements Design Planning Implementation Tes4ng & QA Deployment Maintenance Spec-driven development Vibe coding
10. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 10 REQUIREMENTS GATHERING & ANALYSIS SYSTEM DESIGN IMPLEMENTATION TESTING DEPLOYMENT MAINTENANCE Back to the V-model or Waterfall?
11. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 11 Do not specify a complete application
12. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 12 Coding agents need the right amount of context Too detailed - Context saturation - Loss of quality - Token consumption Single prompt Full applica<on specifica<ons Balanced - Task-oriented context - One task per session - Precise constraints provided Too vague - Incomplete - Ignore constraints - Lengthy conversa@ons
13. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 13 Adjust the size of your specs Adjust the size of your tasks Application level Epic / Feature level
14. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 14 What granularity? Task complexity, coupling, dependencies Must fit in one iteration Must deliver business value Independent & Autonomous teams
15. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 15 Don’t throw Agile out with AI bathwater Requirements Design Planning Implementation Tes4ng & QA Deployment Maintenance Spec-driven development Vibe coding Specify and ship fine-grained tasks, collect feedback, iterate
16. © 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved. Amazon Confidential and Trademark. 16 AI doesn’t change those principles, it accelerates them. - Agile Manifesto - Working software over comprehensive documentation Responding to change over following a plan