We are uncovering better ways of developing software alongside AI. Through this work we have come to value:
Shared understanding over working software
Independent challenge over efficient agreement
Teaching the why over delivering the what
Pace of learning over pace of shipping
That is, while there is value in the items on the right, we value the items on the left more.
"Individuals and interactions over processes and tools" argues that people matter more than process. This addendum argues that what those people understand matters more than what they produce with AI.
"Working software over comprehensive documentation" argues that working software is more important than documentation. This addendum argues that the way we arrive at working software matters. It is no longer the case that working software is proof that the team understood the problem.
"Customer collaboration over contract negotiation" argues that understanding develops in conversations with the customer, not in the contract. This addendum extends this argument inward to the conversations between team members.
"Responding to change over following a plan" argues we should respond to change rather than following a rigid plan. This addendum argues that people cannot respond to change if they do not understand what they already built.
The twelve principles behind the Agile Manifesto still hold. Three need refinement:
3. Deliver working software frequently, but never faster than it can be deeply understood.
7. Shared understanding of the systems we build, demonstrated through working software the team can explain, is the primary measure of progress.
8. Agile processes promote sustainable development. Sponsors, developers, and users should be able to maintain a constant pace of building shared understanding indefinitely.
"Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale." The original optimizes for delivery speed because delivery and understanding were intertwined. The update acknowledges that AI broke this assumption, and requires the team to understand a solution before delivering it.
"Working software is the primary measure of progress." The original assumed that working software was a proxy for understanding. The update makes explicit what the original was tracking by proxy.
"Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely." The original protects against burnout from overwork. The update recognizes that burnout also comes from the accumulated cost of maintaining code the team doesn't understand.
Matthew Cullum
VP of Engineering, thatDot Inc.
March 13, 2026
Twenty years leading software engineering teams, from system architecture to organization design.
