Architectural Drivers
The small subset of requirements whose change would force the structure to change.
4 to work through
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intermediate
You are designing a payments API. Peak volume is modest - a few thousand requests per second. What is the dominant architectural driver and what does it force into the design?
2 min answer -
intermediate
Zepto's product promise is a ten-minute grocery delivery. An architect is handed a backlog of forty requirements. Which one is the architectural driver, and what does that classification actually change?
2 min answer -
advanced Multiple choice
A large ERP programme was designed around performance and integration. Eighteen months in it fails audit - not because it is slow or badly integrated, but because it cannot demonstrate who changed a financial record and why. Which architectural driver was missed, and why is this structural rather than a missing feature?
1 min answer -
advanced
A system meets every SLO but the business is unhappy because feature delivery has slowed to a crawl. What is being measured wrongly, and when is reducing distribution the right scalability investment?
2 min answer
4 terms in this topic
Architectural Drivers
The handful of requirements whose change would force the structure to change — the only ones worth designing against.
practiceArchitecturally Significant Requirement
The small subset of requirements whose change would force the structure to change - the only ones an architecture document owes an answer to.
practiceCapacity Borrowing
Serving an unpredictable new load from an existing shared fleet by displacing lower-priority work, which requires that the displaceable work be ident…
practiceCounterfactual Structure Test
The one-question test that separates architectural drivers from important features - remove this requirement, and would the structure of the system change?
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.
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.
Coupling
How much one component must know about, or change alongside, another.
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.