Yesterday we held another great life michael meetup, this time dedicated to a topic that is quickly becoming central to modern software development: the contrast between Vibe Coding and Spec-Driven Development (SDD). The meetup took place online. Software developers from around the world participated. In addition, we had many team leads, architects, and tech managers, all eager to understand how GenAI is reshaping the way we build software.
Why This Topic Matters Today
GenAI has already become a standard part of the development workflow. As we discussed, developers increasingly rely on AI for code completion, generating project skeletons, reviewing code, writing tests, creating documentation, and even performing agentic coding tasks. This rapid evolution forces us to examine how we work, not just what we build. Two very different approaches have emerged: Vibe Coding (fast, intuitive, improvisational, and deeply compatible with AI-driven creativity) and Spec-Driven Development (structured, predictable, and aligned with AI-native workflows, where specifications serve as the control layer for agents and automation). Our goal in this meetup was not to declare a winner, but to understand when each approach excels – and what tradeoffs come with it. You can find more information about this meetup at https://www.meetup.com/lifemichael/events/311134931.
Vibe Coding: Speed, Flexibility, and Flow
Vibe Coding offers developers an outstanding sense of momentum and a flexibility that allows coding even if the programming language is not known. It is ideal when:
- You need rapid prototyping
- You are experimenting with new ideas
- You are building simple tools or personal automations
- You want minimal friction and maximum creative flow.
With AI tools boosting the experience, developers can iterate extremely quickly and keep their focus on behavior and user experience rather than formal structure. However, we also emphasized the downsides: long-term maintainability, code quality, and the risk of creating “black box” codebases that are difficult to debug or extend
Spec-Driven Development: Structure, Alignment, and AI-Native Engineering
SDD places structured, machine-interpretable specifications at the center of the development lifecycle. These specs—expressed as EARS requirements, UML diagrams, state machines, scenarios, constraints, and data contracts – become the single source of truth, guiding:
- Architecture & Design
- Code Generation
- Testing Generation
- Documentation
- Multi-Agent Workflows in IDEs such as Kiro
This results in systems that are more consistent, easier to onboard new developers into, and significantly more transparent and maintainable. At the same time, SDD introduces challenges: upfront effort, increased formality, initial complexity, and the need for a mindset change in teams that so far were used to jumping straight into coding
When Each Approach Fits?
The key takeaway from the meetup was that there is no universal methodology for every situation.
Vibe Coding shines for prototypes, disposable tools, and early exploration. It allows developers to iterate quickly, experiment freely, and validate ideas without the overhead of formal specifications.
Spec Driven Development becomes essential for large, long-lived, multi-team, AI-driven systems that require traceability, governance, reliability, and strict alignment between specifications, code, and tests.
The real skill for tomorrow’s developer is knowing when to use each, and sometimes even blending them effectively within the same workflow.
The Talk Was Captured on Video
The video clips of all the talks I deliver, including the one that took place in this meetup, are available online for free on YouTube.
The Slides are Available Online
The slides of all the talks I deliver, including the one that took place in this meetup, are available online for free at slideshare.net.
Thanks for Attending The Meetup
It was inspiring to see so many developers and managers from around the world (including countries with whom Israel still doesn’t have a peace agreement, such as Oman and Saudi Arabia) engaging with the material, asking questions, and exploring how these methodologies can improve their teams’ productivity and code quality.
