Contract at the boundary
Making the agreement between a service and its consumers explicit, with an interface, a versioning and deprecation policy, and automated contract tests that catch a breaking change before integration does. It is the technical half of ownership and contract at the boundary.
Evidence grade: practice A widely adopted practitioner model with clear provenance.
Use it when
Teams that keep breaking each other's integrations; any widely consumed interface.
Where it stops working
It verifies only the contract that was written down and cannot create interface discipline where there is none. At a boundary with a single consumer and no history of breakage, it is overhead.
Where the standard uses it
- DE-4Managing scope, risk, and dependencies across workstreamsSeeing the whole, naming the risk, negotiating the boundary.
- TJ-3Code review and quality standardsIncluding standards for AI-generated code.
Sources
- Matthew Skelton and Manuel Pais. Team Topologies: Organizing Business and Technology Teams for Fast Flow. IT Revolution Press, 2019. In the bibliography
Used alongside it
- Aligned autonomy practice
- Code review as knowledge transfer research
- Conway's law practice
- Ground truth and status criteria practice
- One-way and two-way doors practice
- Quality as a system practice
Cite this model
Chicago, BibTeX and licence →Engineering Management Academy. (2026). Contract at the boundary. In Engineering Management Academy Body of Knowledge (Version 3.1, TEC.contract-at-the-boundary). https://www.engineeringmanagement.academy/body-of-knowledge/techniques/contract-at-the-boundary