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126 questions, 454 terms and 400 topics in 20 areas.
60 results for “Trade-off Fundamentals”
Architecture Trade-off Analysis Method
A structured evaluation that scores an architecture against prioritised quality-attribute scenarios and identifies the points where those attributes conflict.
Cost vs Reliability Trade-off
The non-linear relationship between availability and spend, which makes each additional nine roughly an order of magnitude more expensive.
Trade-off Analysis
Making the costs of an architectural choice explicit and comparable, rather than presenting a recommendation as if it were free.
Security vs Usability
A trade-off that is usually resolved by varying the control with the value of the action, rather than by choosing a uniform level of friction.
Dropbox's Move Off S3
Dropbox moved the majority of its file storage off Amazon S3 onto custom infrastructure, reporting savings that its S-1 filing put at roughly $75 million over two years.
Abstraction
Exposing what a component does while hiding how it does it, so callers depend on the contract rather than the mechanism.
Architectural Driver
The small subset of requirements and constraints that actually shape the structure of the system.
Architecture Principle
A durable, agreed rule that constrains design decisions in advance, stated with its rationale and its implications.
Architecture Style
A named, coarse-grained way of organising a whole system, as distinct from a pattern that solves one recurring problem inside it.
Cohesion
The degree to which everything inside one component belongs together and changes for the same reason.
Conway's Law
Systems tend to mirror the communication structure of the organisation that builds them.
Coupling
The degree to which one component must know about, or change alongside, another.
Delivery vs Maintainability
Choosing where to take deliberate shortcuts, based on which kinds of debt are cheap to repay and which compound.
Denormalisation
Deliberately duplicating data across records to make reads cheap, accepting the write-time cost of keeping copies in step.
Encapsulation
Keeping a component's state private, so it can only be changed through operations that maintain its invariants.
Etsy's Continuous Deployment
Etsy moved from infrequent, risky releases to dozens of deploys a day, demonstrating that deployment frequency and stability improve together rather than trading off.
Evolutionary Architecture
Designing for guided, incremental change rather than trying to get the structure right once, up front.
Fitness Function
An automated check that an architectural characteristic still holds, run continuously rather than reviewed occasionally.
Instagram's Early Scaling
Instagram reached tens of millions of users on Django and PostgreSQL with a handful of engineers, by deliberately choosing boring technology and doing the simple thing first.
Modularity
The degree to which a system is composed of parts that can be understood, changed and replaced independently.
Monolith vs Microservices
A trade of deployment independence against distributed-systems complexity, decided by team topology far more often than by technology.
Negotiation
Reaching an agreement that both sides own, by trading on interests rather than arguing positions.
Non-Functional Requirement
A requirement about how well the system must behave rather than what it must do — latency, availability, throughput, security, cost.
Quality Attribute Scenario
A structured, testable statement of a non-functional requirement: source, stimulus, environment, artefact, response, response measure.
Separation of Concerns
Organising a system so each part addresses one concern, and a change to that concern touches one part.
Solution Architecture
The design of a specific system that satisfies a specific business problem under a specific set of constraints.
TCP/IP
The layered protocol suite underneath essentially all application traffic — IP routes packets, TCP turns them into a reliable ordered stream.
Netflix built its own CDN; Dropbox moved storage off S3. Both are usually wrong. What conditions made them right, and how do you test for those conditions?
What the interviewer is testing Whether you can extract the conditions from a famous decision rather than the decision itself. These two cases are the most comm
A team shows you a design with eight services. Without knowing the domain, what questions tell you whether the boundaries are right?
What the interviewer is testing Whether you can evaluate a structure from its properties rather than needing to be a domain expert in every system you review. T
Instagram served 14 million users with three engineers on Django and Postgres. What does that tell you about how to choose an architecture for a new product?
What the interviewer is testing Whether you can identify the binding constraint. For most products it is not traffic. What Instagram actually did Their 2011 pos
The team can ship in six weeks with an approach that will need rework, or five months with one that will not. How do you decide, and what do you do either way?
What the interviewer is testing Whether you can make a debt decision deliberately rather than by default, and whether you know which debts are cheap and which a
Trade-off Fundamentals
Why every architecture is a set of purchases, and how to state what you gave up.
Trade-off Analysis
Making costs explicit and comparable rather than asserting a preference.
Trade-off Analysis Methods
ATAM, scenarios, and naming the points where qualities conflict.
Architecture Fundamentals
General material on what solution architecture is and what an architect is accountable for.
Explaining Trade-offs
Naming what was given up, and the condition that would change it.
Abstraction & Encapsulation
Hiding mechanism behind contract, and protecting invariants by owning state.
Architectural Drivers
The small subset of requirements whose change would force the structure to change.
Architecture Documentation
What to write down, at what altitude, and what nobody will ever read.
Architecture Patterns
General material on architectural patterns and their trade-offs.
Architecture Principles
Durable agreed rules that rule options out, stated with rationale and implications.
Architecture Roles
Solution, enterprise, domain and platform architecture, and where each is accountable.
Architecture Styles
System-level organising shapes, and how they differ from problem-level patterns.
Capability Maps in EA
The stable frame for hanging investment, ownership and health off.
Cohesion
Whether the things inside a boundary belong together and change for the same reason.
Conway's Law
Systems mirroring the communication structure of the organisation that builds them.
Coupling
How much one component must know about, or change alongside, another.
DORA Metrics
Throughput and stability moving together rather than trading off.
Decommissioning
Actually switching the old system off, and proving nothing depended on it.
Evolutionary Architecture
Designing for guided incremental change rather than for correctness on day one.
Fitness Functions
Automated checks that an architectural characteristic still holds.
Functional vs Non-Functional
Behaviour versus quality of behaviour, and why only the second constrains structure.
Modularity
Composing a system from parts that can be understood and replaced independently.
Multi-Agent Systems
Coordination, hand-off and whether more agents actually help.
Quality Attributes
Availability, latency, throughput, security, cost — expressed as testable scenarios.
Reference Models
Shared conceptual frames — layering, tiers, viewpoints — and their limits.
Requirements to Constraints
Turning stated requirements into the constraints that actually bound a design.
Separation of Concerns
Organising so that a change to one concern touches one place.
Technical Constraints
Existing estate, skills, licences and platforms as inputs rather than obstacles.