Search the practice set
126 questions, 454 terms and 400 topics in 20 areas.
60 results for “Systems Thinking”
Systems Thinking
Reasoning about a system in terms of the interactions and feedback loops between its parts, rather than the parts individually.
Constraint Thinking
Designing for the budget, timeline, skills, regulations and existing estate that actually exist, rather than for the ones a textbook assumes.
Failure Thinking
Making "what happens when this fails?" a standing question applied to every component and every dependency in a design.
Product Thinking
Treating what you build as something with users, a value proposition and a lifecycle, rather than as a project that completes.
Backpressure
A mechanism by which a component under load tells its callers to slow down, rather than accepting work it cannot complete.
Bulkhead
Partitioning resources so that exhaustion caused by one dependency or tenant cannot starve the others.
CAP Theorem
During a network partition a distributed system must choose between consistency and availability; it cannot have both.
Circuit Breaker
A proxy that stops calling a failing dependency after a failure threshold, failing fast instead, and periodically tests whether it has recovered.
Consistent Hashing
A hashing scheme where adding or removing a node remaps only a small fraction of keys, instead of nearly all of them.
Continuous Compliance
Producing compliance evidence automatically and continuously from the systems themselves, rather than reconstructing it before an audit.
Conway's Law
Systems tend to mirror the communication structure of the organisation that builds them.
Event Stream
An append-only, retained log of events that many independent consumers read at their own position, and can re-read.
Event-Driven Integration
Systems integrating by publishing and consuming events rather than by calling each other's APIs.
Eventual Consistency
A guarantee that replicas will converge to the same value if updates stop, with no bound on how long reads may be stale.
Exponential Backoff
Increasing the wait between retries geometrically, with random jitter, so that failures do not synchronise into a stampede.
Fan-Out
One incoming request causing many outgoing ones, which multiplies both load and tail latency.
Fault Tolerance
Continuing to operate correctly despite the failure of some components, by design rather than by luck.
Graceful Degradation
Continuing to deliver reduced but useful function when a dependency fails, instead of failing the whole request.
Idempotency
The property that performing an operation many times has the same effect as performing it once.
Leader Election
The process by which a group of nodes agrees which one of them is currently in charge of a task that must not run twice.
LinkedIn and the Origin of Kafka
Kafka was built to replace point-to-point data integration between many systems with a single durable log that any system could publish to and any number could read.
In the 2017 AWS S3 outage, the status page could not report the outage because it depended on S3. What does that tell you about designing status and control systems?
The case, as publicly reported On 28 February 2017, an authorised engineer running an established playbook to debug an S3 billing issue in us east 1 entered a c
In the October 2021 Meta outage, engineers reportedly struggled to physically access equipment because the access-control systems were also down. What class of dependency is that, and how do you find yours?
The case, as publicly reported On 4 October 2021, a command issued during routine backbone capacity assessment took down all connections between Meta's data cen
PCI DSS assessment covers 40 systems and costs a fortune annually. How would you reduce that architecturally?
The principle Scope follows the data. Any system that stores, processes or transmits cardholder data is in scope and inherits the full control set. Reducing sco
A 43-second network partition caused GitHub over 24 hours of degraded service in 2018. How does a 43-second event become a day-long incident?
The case, as publicly reported On 21 October 2018, routine maintenance replacing failing optical equipment caused a 43 second loss of connectivity between GitHu
A card payment authorisation service runs active-active across two regions. A network partition splits them. Do you keep accepting authorisations, and what breaks either way?
What the interviewer is testing Whether you can apply CAP to a domain where the cost of each choice is concrete, and whether you recognise that "it depends" has
A downstream service slows from 50 ms to 3 s. Within two minutes every service in the request path is down, including ones that do not call it. Explain the mechanism and how you would have prevented it.
What the interviewer is testing Whether you understand that most outages are amplification, not failure — and whether you can name the specific mechanism rather
An order service must notify inventory, billing, shipping and analytics when an order is placed. Synchronous calls or events? Justify your choice per consumer.
What the interviewer is testing Whether you apply the decision per interaction rather than adopting one style globally. The framing that matters Synchronous cal
Design an order submission API that is safe when the client cannot tell whether its request succeeded. What exactly do you store, and when?
What the interviewer is testing Whether you know that "make it idempotent" is a design with specific failure modes, not a checkbox. The core design The client g
Systems Thinking
Interactions and feedback loops rather than isolated components.
Constraint Thinking
Designing for the budget, skills and regulations that actually exist.
Debugging Distributed Systems
Localising a regression when every service reports healthy.
Distributed Systems
General material on partial failure, coordination and distributed reasoning.
Failure Thinking
Asking of every box and arrow how it fails and how you would know.
Multi-Agent Systems
Coordination, hand-off and whether more agents actually help.
Product Thinking
Treating platforms and services as products with users and a lifecycle.
AI-Era Architecture
General material on architecting systems that include models.
API & Integration
General material on integrating systems through contracts.
Backpressure & Flow Control
Telling callers to slow down instead of buffering into congestion collapse.
Bulkheads & Isolation
Partitioning resources so one dependency cannot starve the others.
CAP & PACELC
What you must give up during a partition, and the latency choice the rest of the time.
Capability Mapping
Overlaying systems onto capabilities to expose duplication and gaps.
Circuit Breakers
Failing fast on a broken dependency, and what you fail fast to.
Clocks & Ordering
Why wall clocks lie, and how logical clocks and versions restore order.
Consensus Protocols
Raft, Paxos and quorums — what they guarantee and what they cost.
Consistency Models
Linearizable, sequential, causal, eventual, and the session guarantees between them.
Context Diagrams
The system as one box, with its users and external systems.
Conway's Law
Systems mirroring the communication structure of the organisation that builds them.
Distributed Locking
Mutual exclusion across machines, and why it is harder than it looks.
Distributed Transactions
Two-phase commit, its blocking failure mode, and when it is still reasonable.
Event Streaming
Retained ordered logs, consumer offsets, partitions and replay.
Failure Modes
Slow rather than down, partial, grey, and failing while reporting success.
Idempotency
Making an operation safe to repeat, because a client that times out cannot know.
Leader Election
Agreeing who is in charge, and fencing the one who no longer is.
Legacy Integration
Reaching systems that cannot change, without importing their model.
Legacy Integration Patterns
Anti-corruption layers, adapters and CDC against systems that cannot change.
Legacy Modernization
General material on modernising existing systems.
Distributed Systems
Many machines, partial failure, and the coordination problems that follow.
API & Integration Architecture
Contracts between systems, and the compatibility discipline that keeps them working.
Legacy Modernization
Real-world architecture is usually about improving systems that already exist.