Coupling
How much one component must know about, or change alongside, another.
4 to work through
-
intermediate Multiple choice
At Meesho-scale marketplace growth, catalogue, pricing, order and logistics teams all read and write one shared product table, each deploying schema changes independently. Which kind of coupling is this, and why does it get worse rather than plateau?
2 min answer -
advanced
A communications API platform finds that adding a new messaging channel requires coordinated changes in the gateway, the billing service, the webhook dispatcher and the console UI, across four teams. What would you change about the coupling, and what should you deliberately leave alone?
2 min answer -
advanced
A company split its monolith into 14 services. Deployments now require a coordinated release plan across teams and one user action traverses six synchronous hops. What went wrong and what would you do?
2 min answer -
advanced
A social product is launched on top of an existing platform's identity, graph and infrastructure, and reaches 100 million users in five days. Which components are safe to borrow, which must be isolated, and what does this say about coupling?
2 min answer
5 terms in this topic
Afferent and Efferent Coupling
The counts of components depending on a module and of components it depends upon, used together to identify which parts of a system are expensive to …
conceptBoundary Traffic Cost
The recurring cost of the data and coordination that cross a component boundary - paid on every request forever, and the number that decides whether …
conceptCommon Coupling
Coupling through shared mutable state, where every participant constrains every other participant's ability to change - the one form of coupling with…
conceptCoupling in Practice
The kinds of coupling that actually hurt, ranked by how much they constrain independent change.
conceptTemporal Coupling
A dependency in which one component requires another to be available at the same moment, so the availability of both is required for either to work.
Neighbouring topics
Architecture Fundamentals
General material on what solution architecture is and what an architect is accountable for.
Requirements to Constraints
Turning stated requirements into the constraints that actually bound a design.
Functional vs Non-Functional
Behaviour versus quality of behaviour, and why only the second constrains structure.
Architectural Drivers
The small subset of requirements whose change would force the structure to change.
Quality Attributes
Availability, latency, throughput, security, cost — expressed as testable scenarios.
Architecture Principles
Durable agreed rules that rule options out, stated with rationale and implications.
Cohesion
Whether the things inside a boundary belong together and change for the same reason.
Modularity
Composing a system from parts that can be understood and replaced independently.
Separation of Concerns
Organising so that a change to one concern touches one place.
Abstraction & Encapsulation
Hiding mechanism behind contract, and protecting invariants by owning state.
Architecture Styles
System-level organising shapes, and how they differ from problem-level patterns.
Evolutionary Architecture
Designing for guided incremental change rather than for correctness on day one.
Fitness Functions
Automated checks that an architectural characteristic still holds.
Architecture Documentation
What to write down, at what altitude, and what nobody will ever read.
Conway's Law
Systems mirroring the communication structure of the organisation that builds them.
Trade-off Fundamentals
Why every architecture is a set of purchases, and how to state what you gave up.
Technical Constraints
Existing estate, skills, licences and platforms as inputs rather than obstacles.
Architecture Roles
Solution, enterprise, domain and platform architecture, and where each is accountable.
Reference Models
Shared conceptual frames — layering, tiers, viewpoints — and their limits.