Originally written in French. Translated by AI — the meaning has been preserved, not the prose.
Short definition
A perimeter inside which a set of terms has a single meaning and a local truth, and at whose border any information coming from elsewhere is translated before entering.
Full definition
The term comes from Domain-Driven Design, where it designates the limit of application of a domain model. One and the same word — "customer", "leave", "order" — receives there a definition that holds only within that perimeter; another bounded context may use the same word for something else, and that is accepted. The border is what makes those two definitions compatible: each stays coherent at home.
In the articles on this blog, the term is taken up outside code, for the workspace of a product opportunity: a directory, its files, its vocabulary, its established facts, its decisions. What comes from another subject is copied there and reformulated in the opportunity's terms, never dynamically linked to its source. The sense of the term is the same as on the development side; only the bounded object changes — a business domain there, a scope of study here.
Usage in the field
The term comes into play as soon as it is a matter of deciding what a workspace contains and what it excludes: sizing a context entrusted to an AI, dividing up an opportunity study, architecting a team knowledge base, integration between two systems.
Synonyms and variants
"Bounded context", "delimited context", "bounded space". In the articles on this blog, "context" used alone most often designates the neighbouring notion of a working goal, not this perimeter of a model.
Not to be confused with
- Context — the perimeter of information mobilized for a given working goal, which may cross several applications and several domains. The bounded context, by contrast, bounds a model and its vocabulary.
- Context window — the amount of text a language model actually has in front of it to answer with. That is a capacity constraint, not a border of meaning.
- Second brain — an apparatus that connects all the notes with no internal border; it is the form of organization the bounded context stands against.
- Silo — an imposed separation that prevents circulation. The bounded context on the contrary organizes that circulation, by translation at the border.
Examples
A payroll system that needs the month's leave doesn't call the leave-management system: it integrates that leave into its "payroll variables" domain, in the form payroll knows how to handle.
A product opportunity worked through in a dedicated directory of thirty to forty files, where all outside information is copied over and adapted to the opportunity's vocabulary.
Ambiguities / debates
Using the term outside software is contested: in Domain-Driven Design, the bounded context delimits a model shared by a team, not an individual working folder. The borrowing made here keeps the principle of border and translation, and leaves aside the modelling apparatus that ordinarily accompanies it.