Search the practice set
126 questions, 454 terms and 400 topics in 20 areas.
60 results for “Multi-Agent Systems”
Shuffle Sharding
Assigning each customer a random combination of workers rather than a fixed shard, so that any two customers rarely share their whole set.
Multi-Cloud
Deliberately running across more than one cloud provider — a decision with a much higher cost than the lock-in it is usually adopted to avoid.
Multi-Factor Authentication
Requiring evidence from more than one category — something you know, have, or are — so a single stolen credential is insufficient.
Multi-Leader Replication
Accepting writes at more than one node and replicating between them, which removes the single-primary bottleneck and introduces write conflicts.
Salesforce's Metadata-Driven Multi-Tenancy
Salesforce serves every customer from shared infrastructure with a single physical schema, storing customer-specific data structures as metadata rather than as separate tables.
Systems Thinking
Reasoning about a system in terms of the interactions and feedback loops between its parts, rather than the parts individually.
Active-Active vs Active-Passive
Whether all regions serve traffic simultaneously, or one serves while another waits to take over — a choice about which failure mode you would rather have.
Availability Zone
One or more physically separate data centres inside a cloud region, with independent power, cooling and network, connected by low-latency links.
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.
Cloud Exit Plan
A documented, costed assessment of what leaving a provider or service would require — increasingly a regulatory expectation and a better lock-in control than portability itself.
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.
Data Residency
A requirement that specific data be stored and sometimes processed only within a defined geography.
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.
A multi-tenant SaaS product has outgrown one database. You must shard. How do you choose the partition key, and what makes this decision so expensive to get wrong?
What the interviewer is testing Whether you exhaust cheaper options first, and whether you understand that a shard key is close to irreversible. First: do not s
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
Leadership asks for multi-region "for resilience". What do you establish before designing anything?
First: is multi region the right answer to the actual problem? Multi region defends against a region wide failure . Most outages are not that — they are bad dep
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
The business asks for "multi-region" after a regional outage. Before agreeing, what do you need to establish, and what are you actually signing up for?
What the interviewer is testing Whether you convert a vague requirement into numbers before designing, and whether you know that multi region is primarily a dat
You are asked to give an internal AI agent access to the customer database, the ticketing system and outbound email so it can resolve support tickets. What is your response?
What the interviewer is testing Whether you recognise a specific and well documented security pattern, and whether you can propose a workable design instead of
You are asked to make a multi-tenant SaaS resilient to "any single failure". You propose cells. What must you find before that claim is true?
What must be found: every shared dependency A cell is isolated only if nothing inside it depends on something shared with another cell. The work of adopting the
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
Multi-Agent Systems
Coordination, hand-off and whether more agents actually help.
Agent Architectures
Loops, planning, memory and the boundaries an agent must not cross.
Debugging Distributed Systems
Localising a regression when every service reports healthy.
Distributed Systems
General material on partial failure, coordination and distributed reasoning.
Multi-Cloud
Best-of-breed, portfolio and portable — three very different costs.
Multi-Region Architecture
Surviving a region, and the data consistency price of doing so.
Single vs Multi-Region
Driven by RTO, RPO and residency rather than by ambition.
Systems Thinking
Interactions and feedback loops rather than isolated components.
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.