AI-DLC · The AI Development Lifecycle · Draft 0.1

When the build takes a night, the thinking is the work.

Agile was a response to waterfall: projects took so long to show results that teams learned to build in small slices and check often. AI agents change the economics again. Building is becoming fast and cheap. Knowing exactly what to build, and proving that what was built is right, is not. The AI-DLC is a way of working for that world. It belongs to no product, and you can run it with the tools you already have.

The shift

The bottleneck has moved upstream, and downstream.

For twenty-five years, the expensive part of software was writing it. Agile, sprints and the backlog were all ways of managing that cost: build a little, show it, learn, repeat.

Agents can now write large parts of a product overnight, and models and token prices are both moving in one direction. It is reasonable to expect agents, in time, to build exactly what they are asked for. At that point the main source of defects is no longer the builder. It is the ask.

So human effort moves to the two ends of the lifecycle. Upstream, people must be precise about intent, and design must be challenged before anything is committed. Downstream, verification must be strong enough to trust work no person typed. Agile's values about people, customers and change still hold. What has changed is where the scarce effort sits.

The manifesto

Building software with agents, we have come to value:

  1. Precise intentoverdetailed task plans
  2. Challenged designsovercorrected builds
  3. Trusted, ranked contextovermore context
  4. Verified outcomesoverdelivered output
  5. Recorded reasonsoverremembered ones

In the spirit of the Agile Manifesto: there is value in the items on the right, but we value the items on the left more.

The lifecycle

The V-model comes back, at agent speed.

When large pieces of a product are built in one pass, you can't rely on catching problems sprint by sprint. Each level of intent needs its matching check, agreed before the build starts. The V was right about that. What was wrong was the months it took to travel. Agents shrink the bottom of the V to hours, so the whole loop can run in days.

The AI-DLC V Four human-led stages descend on the left: Intent, Shape, Challenge, Specify. Agents build at the bottom. Four stages rise on the right: Verify, Validate, Accept, Learn. Each right-hand stage checks its matching left-hand stage. Learning from production feeds back into the next Intent and into test data. production evidence feeds the next intent and the test data 01Intentoutcome and why 02ShapeAI asks, humans decide 03Challengetest the design first 04Specifychecks before code 05 Build agents · hours, not sprints 06Verifymeets the spec 07Validatedesign holds as a whole 08Acceptnamed person signs off 09Learndid it work? human-led evidence-led
  1. 01 · Intent

    Say what outcome you want, and why

    A named person states the outcome, who it is for, the constraints, and how anyone will know it worked. One Intent may change code, documents, training or anything else the organisation produces.

    Owner: a person
  2. 02 · Shape

    Let AI find the gaps

    AI interrogates the Intent: missing cases, conflicts with earlier decisions, unstated assumptions, scope that should be split. People answer and decide. The result is precise enough to be built literally.

    AI proposes · people decide
  3. 03 · Challenge

    Challenge the design before committing

    The design faces structured challenge from AI and from specialists such as security, data protection, architecture and regulation. Each challenge gets an answer or a reason for dismissing it, and both are recorded.

    Challengers: AI and specialists
  4. 04 · Specify

    Write the checks before the code

    For each level of intent, agree how it will be proven: acceptance criteria, system and integration tests, component tests, and the test data they need. Ideally these are written by someone, or something, other than the builder.

    People and test agents
  5. 05 · Build

    Let agents build, often overnight

    Agents build against the specification and generate the documentation and trace links as they go. Throwaway prototypes are welcome at any earlier stage. They sharpen the spec, and the spec is what you keep.

    Agents, with people on call
  6. 06–07 · Verify and validate

    Prove it, continuously

    Automated checks run at every level on production-representative data. Verify asks "was it built as specified?" Validate asks "does the design hold up as a whole: performance, resilience, security?"

    Automated, independent
  7. 08 · Accept

    A person accepts against the Intent

    A named person reviews the evidence against what was asked for and signs off. Agents can recommend, but they never approve their own work.

    Accountable: a person
  8. 09 · Learn

    Release in steps, then measure the outcome

    A one-pass build is not a big-bang release. Ship progressively behind flags or canaries, measure whether the outcome happened, and feed what production teaches back into the next Intent and into the test data.

    Evidence closes the loop
Principles

Twelve principles behind the AI-DLC.

  1. Human effort moves to the front

    When building takes hours, the time people spend getting the Intent right is the best investment in the lifecycle. A day of clear thinking now saves a night of precise, wasted building.

  2. Write as if it will be built literally

    Expect agents to do exactly what is asked, and increasingly to do it without mistakes. Ambiguity becomes the main source of defects, so treat vague language in an Intent as a defect in its own right.

  3. AI shapes intent, people own it

    AI is excellent at asking the questions people forget: edge cases, conflicts, missing acceptance criteria. Use it to sharpen every Intent, but keep a named person accountable for what it says.

  4. Challenge before you commit

    Every significant design is challenged before the build, by AI and by the specialists who would otherwise find the problem later. Challenges that are dismissed need a reason, and the reason is kept.

  5. Context has an order of authority

    AI can read everything, so what it reads must be trusted. Rank sources, mark where each one came from, and treat stale or unverified material as a risk rather than more input. See the ranking.

  6. Newer, informed decisions win

    A recent decision overrides an older one only if it was made knowing about the older one. Decisions are superseded explicitly, never silently edited, so anyone can follow the chain.

  7. Code is the truth, so the repository explains itself

    People are poor at maintaining code documentation, and AI is good at it. Agents generate and update architecture notes, module docs and decision records in the repository with every change. Documentation that drifts from the code fails the build.

  8. Every change carries its why

    Each commit and merge links to the Intent and decisions behind it, using plain text in the commit itself. Git history then answers "why was this changed?" without needing any particular tool. See an example.

  9. Verification is designed with the intent

    Each level of intent has a matching check, agreed before the build. The checks should be independent of the builder: a different agent, a different model, or a person.

  10. Test data is a product

    Generate synthetic test data from the data model before anything is built. Keep it honest with a feedback loop from production: shapes, volumes, distributions and edge cases, never raw customer data. Drift between test and production data is a defect.

  11. The MVP becomes the minimum verified product

    The "minimum" in MVP was about the cost of building. When building is cheap, build several variants to learn, keep the best specification, and throw the code away. What you ship is still small, but it is fully verified and carries its controls from day one.

  12. Tool-agnostic by design

    The AI-DLC is a way of working, not a product. Keep its records in open formats that live with the work: markdown in the repository, links in commits, tests in the pipeline. Your evidence should outlast any vendor, including us.

Context authority

Not all knowledge is equal.

Agents can take in every document, chat and wiki page an organisation has ever written. Most of it is out of date, and some of it contradicts the rest. Feeding all of it to an agent with equal weight is how confident, wrong work gets built.

A starting order of authority, highest first. Each organisation should set its own, write it down, and give it to every agent it uses.

  1. Running code and passing tests
    What the system actually does today.
  2. The latest informed decision
    Recorded, attributed, and made with knowledge of what it replaces.
  3. The approved Intent and its specification
    What was agreed for this change.
  4. Documentation kept in the repository
    Trusted to the extent that checks keep it in step with the code.
  5. Conversations and transcripts
    Useful evidence, but not a decision until someone confirms it.
  6. External and generated material
    Use with care, cite the source, and verify before relying on it.
Traceability without lock-in

Put the why in the history.

The simplest way to make every change traceable is to write the links into the commit itself. Git trailers are plain text, every tool can read them, and they stay with the code wherever it moves.

The identifiers can point at anything: a markdown file in the repository, a page in a wiki, or a record in a work management tool. The AI-DLC only asks that they exist and that they resolve.

Raise daily payment limit for business accounts

Applies the new limit to the business tier only and
adds limit checks to the payment validation service.

Intent: INT-142 Raise business payment limits
Decision: DEC-311 Limit set at £250k (risk review)
Decision: DEC-298 superseded by DEC-311
Verified-by: tests/payments/limits_spec
Agent: coding-agent, approved model, skill v1.4
Reviewed-by: A. Person <a.person@example.com>
# Illustrative example
From agile to AI-DLC

What changes, and what doesn't.

Agile got the important things right: people over process, working software, close collaboration with customers, and responding to change. The AI-DLC keeps those values and changes the practices built around the cost of writing code.

In agile practiceIn the AI-DLC
SprintIntent: work moves when it is clear and verified, not when the calendar says so
Backlog grooming and story pointsShaping and challenge: effort goes into precision, not estimation
User storyIntent with acceptance checks agreed before the build
Definition of doneVerified against the Intent and accepted by a named person
Daily stand-upLive status from the work itself; people meet to decide, not to report
VelocityTime from Intent to verified outcome, and rework caused by ambiguity
Minimum viable productMinimum verified product, informed by cheap throwaway variants
Wiki pages and tribal knowledgeA repository that explains itself, with decisions linked to every change
Similar names, different things

AI-DLC, ADLC, and AWS's AI-DLC are not the same thing.

Several lifecycles for the AI era have names that sound alike, and one shares our acronym. They solve different problems.

ADLC

Agent Development Lifecycle

A lifecycle, used by several vendors, for building AI agents as products: scoping an agent, evaluating its behaviour, and monitoring it in production. Its subject is the agent itself. Ours is about the work that people and agents do together.

AI-DLC, from AWS

AI-Driven Development Life Cycle

AWS's method for building software with AI as a central collaborator. It runs in three phases (Inception, Construction and Operations), replaces sprints with short "bolts", and elaborates requirements with the whole team in the room. We share its view that intent comes first, and we cite it below.

AI-DLC, on this page

AI Development Lifecycle

A way of working for building any software, document or change with agents, owned by no vendor and tied to no tool. It adds a challenge stage before commitment, a ranked order of trusted context, verification agreed before the build, and evidence that a regulator can follow.

Standing on others' thinking

What we built on, and where we differ.

Plenty of people are rethinking the lifecycle for AI. Spec-driven development, AWS's own AI-DLC and recent agile manifestos for AI all agree that intent and verification matter more than ever. We have learned from all of them.

Where our AI-DLC differs: it is not tied to any tool or vendor; it treats the trustworthiness of context as a first-class problem; it adds an explicit challenge stage before commitment; and it is written for organisations that must prove how every change was made.

Tolvane and the AI-DLC

You don't need Tolvane to work this way.

A repository, markdown, commit trailers and a good pipeline will take you a long way. Tolvane is being built for teams that want the AI-DLC to run at enterprise scale, with people and agents working on Intents together, challengers your specialists configure, a decision record for every change, and evidence a regulator can follow.

This is a draft, and we'd welcome challenge on it. Tell us what we've got wrong.

  • Intents as the unit of work, not tickets
  • AI challengers configured by your own specialists
  • Decisions superseded, never silently edited
  • Links from every change back to its Intent, in your own Git history
  • Works alongside the tools you already use