200apps · how we work
Glossary
The corpus uses a small, deliberate vocabulary. Words mean what is written here — not what they mean elsewhere. When the corpus says prediction, it does not mean guess. When it says witnessed, it does not mean researched.
ADR — Architecture Decision Record
A constrained technical choice with at least two options considered, the chosen option named, the trade-offs explicitly accepted, and the consequences listed. Lives next to the system it constrains. See Volume III · ADR.
Amigos
A trio session — PO, Developer, QA — that takes one story and produces named Gherkin scenarios in 45 minutes. Not a workshop. The smallest unit of shared meaning before code begins. See Volume III · Amigos & Gherkin.
Brief
A written prediction. Has a baseline, a target, a check date, a check method, and an owner. Three flavors — Initiative, Feature, Technical Design — each one cross-referenced.
Chain
The sequence Strategy → Discovery → Scope → Execution → After We Build. Each phase produces the artifact the next phase needs. Defects trace to a level in the chain.
Check
The act of reading the signal a prediction asked to be measured against. Not a survey. Not an impression. The specific measurement named in the brief.
DoR — Definition of Ready
A nine-point checklist a story must pass before it can be pulled into a sprint. See Volume III · Story Writing.
Domain language
The named-thing vocabulary of the person whose problem we are solving. The same words that appear in the brief should appear in the code, the API, the database, and the analytics events. See Volume IV · Domain Language in Code.
DORA
Four system signals — lead time, change failure rate, deploy frequency, MTTR. Tracked at portfolio level, not story level. See Volume V · System signal tracking.
Epic
A coherent activity that produces a user-visible outcome and contains a small number of stories. Epics are named for what the person does, not what the system builds.
Feature flag
A runtime switch that wraps new behavior. Enables release without deploy and rollback without rebuild. Has a lifecycle: create → wire → test → enable → clean up.
Five Stations
The Discovery sequence — Vision & Context, Problem Framing, User Journey & Slices, Solution Options, Decision & Scope. Walked top to bottom. Stations are not skipped.
Gherkin
Given/When/Then scenario language. The Given describes the person's situation, not the system state.
Gate
A named condition the chain must satisfy before the next phase begins. The release gate is the most familiar. Each phase has one.
Ility
A non-functional requirement — accessibility, performance, security, learnability, durability. Selected per Epic by the Tech Lead and the PO. The chosen ilities go in the ADR.
Journey
The ordered set of steps a named person takes to accomplish an activity. Numbered J1, J2, …. Stories reference the journey step they belong to.
Maturity
A self-declared status on every page — gap, seed, draft, stable, reviewed. Used to surface gaps in the corpus.
Model
The team's current best understanding of the situation. Updated by check, not by talk. The act of writing down what was learned is the model update.
Moment
A specific point in a journey where the friction or failure occurs. Discovery names the moment, not the average experience.
Owner
The role that produces or stewards an artifact. Not the person — the role. Roles can combine in small teams; they cannot disappear.
PDR — Product Decision Record
Scope or priority decision with rejected options. The product analogue of an ADR.
Person
A named individual the chain is for. Dina, Miri, Avi. Not the user.
Phase
One of the five volumes — Strategy, Discovery, Scope, Execution, After We Build.
Portfolio
The collection of initiatives, products, and features the organization is currently funding. Reviewed quarterly. Initiatives can be funded, continued, or killed.
Prediction
A claim about what will change, written before the cycle runs. Has a baseline, a target, a check date, a check method, and an owner. A claim without these is not a prediction.
Resolution gate
A named end-of-phase checkpoint. Each volume has one or more. They confirm the chain is allowed to continue.
Retrospective
A three-question conversation — what carried, what broke, what changes. One change. Owned and dated.
Runbook
A written procedure for a known operational situation. Authored before the situation occurs and rehearsed in staging. Lives next to the service it covers.
Signal
A measurement. Three classes — leading (adoption, completion, error encounter rate), lagging (the prediction metric, support volume, retention), system (DORA).
Slice
A subset of stories that together change the situation enough to be released. The walking skeleton is the first slice.
SLA
A written promise to a client about availability, response time, resolution time, and data integrity. Reviewed quarterly with the client.
SLO
A measurable target inside the team — error rate, latency, queue depth — that triggers action when crossed. Defined in ADRs.
Story
A unit of work — one named person, one moment, one outcome — sized 1–3 days, with at least three testable acceptance criteria.
Trio
The smallest decision unit — PO, Developer (often Tech Lead), QA. Decides scope at amigos, names epic kickoff, owns the slice.
VRI
Value-to-Rework Index. The financial-translation metric. The ratio of value declared to rework produced — a portfolio-level measure of chain health.
Walking skeleton
The smallest end-to-end release that changes the situation. Not the smallest feature — the smallest coherent slice.
Witnessed
Observed in person, in the moment, doing the activity. The opposite of described. Discovery is witnessed, not interviewed.