Search the practice set
126 questions, 454 terms and 400 topics in 20 areas.
32 results for “Team Topologies”
Cognitive Load
The total amount a team must hold in its head to work effectively, and a real constraint on how many services or domains one team can own.
Two-Pizza Team
Amazon's heuristic that a team should be small enough to be fed by two pizzas, and — the substantive part — should own its service end to end.
WhatsApp's Small-Team Scale
WhatsApp served hundreds of millions of users with a few dozen engineers by matching one technology choice precisely to the workload and refusing to add anything else.
Conway's Law
Systems tend to mirror the communication structure of the organisation that builds them.
Game Day
A scheduled exercise in which a failure is deliberately introduced and the team responds as though it were real, to test the system and the response together.
Monolith vs Microservices
A trade of deployment independence against distributed-systems complexity, decided by team topology far more often than by technology.
Spotify's Squad Model and Its Retrospective
The widely-copied Spotify model of squads, tribes, chapters and guilds was a snapshot that did not work as documented even at Spotify — a caution about importing organisational design.
A downstream team needs to react to order changes. The order service can publish events, or they can consume CDC from its database. Which, and why?
The recommendation: published events, with CDC as the mechanism if needed The distinction that matters is what the consumer becomes coupled to . CDC consumed di
A nightly job occasionally runs twice, producing duplicate charges. The team proposes a distributed lock. What do you say?
The first response A lock will reduce the frequency and will not eliminate it , and if the team believes otherwise they will stop looking for the real fix. The
A regulator asks whether customer data is encrypted. The team says yes, disks are encrypted. Is that a sufficient answer?
What disk encryption actually protects against Someone obtaining the physical medium or a raw storage snapshot. In a cloud context that means a provider employe
A team is launching a new service and asks what its SLO should be. How do you help them decide, and why is "99.99%" usually the wrong first answer?
What the interviewer is testing Whether you treat reliability as a cost benefit decision with a budget, or as a virtue to maximise. Why not four nines It costs
A team proposes CQRS for a CRUD admin panel because reads are slow. Is that the right call?
Why not CQRS here "Reads are slow" is a symptom with many causes, and CQRS addresses only one of them: the read and write models having genuinely different opti
A team proposes circuit breakers on every downstream call. What would you add, and why is the breaker not the most important control?
Why the bulkhead matters more A circuit breaker acts after it has detected a pattern of failure. During the seconds before it trips — and while its threshold is
A team proposes moving personalisation to edge functions to cut latency. When does that work and when does it backfire?
The principle that decides it The edge is near the user and far from your data. Edge compute pays off for work that needs the request but not your state . The m
A team proposes storing the customer's address on every order row "so order history is accurate". Is that denormalisation or a modelling error?
The distinction that matters It is neither, quite — it is a temporal modelling requirement being solved by accident. Denormalisation duplicates a fact for perfo
A team says "backups run nightly and are retained for 30 days". You have one hour to assess whether they could actually recover. What do you check?
The checks, in the order that finds problems fastest 1. When was a restore last performed, and how long did it take? The single most informative question. If th
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
A team tells you backups run nightly and are retained for 30 days. What is missing from that answer?
What the interviewer is testing Whether you know that a backup is not a control until it has been restored — one of the most reliable ways to find an unrecovere
A team wants event sourcing for a new order service, citing audit requirements. What do you recommend?
The recommendation: probably an audit log, not event sourcing If the requirement is audit , event sourcing is a very expensive way to obtain it. An append only
A team wants to build a new internal API on serverless functions. It will serve steady traffic of about 200 requests per second during business hours. What do you advise?
What the interviewer is testing Whether you can apply the serverless trade off to a specific workload rather than treating it as a default good or a default bad
A team wants to move a workload from PostgreSQL to a document store because "the schema keeps changing". What do you ask?
The questions 1. What is actually changing — the shape, or the schema management process? "The schema keeps changing" usually means migrations are painful, not
A team wants to self-manage Kafka on Kubernetes to save money against the managed service. Evaluate.
The comparison they have probably made Instance cost versus managed service list price. That comparison usually favours self managing by a wide margin, and it o
Every deployment produces a small spike of 502s that the team has learned to ignore. Fix it.
The cause In flight requests are being severed because the instance terminates before the load balancer has stopped sending to it, or before existing requests c
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
You must choose a data store this week. The product team cannot tell you the expected query patterns or the growth rate. What do you do?
What the interviewer is testing How you behave when the information you would like does not exist — which is the normal condition, not the exception. Both "refu
Team Topologies
Stream-aligned, platform, enabling and complicated-subsystem teams.
Backend for Frontend
A narrow backend per client experience, owned by that client's team.
Centralised vs Distributed
Shared platform leverage against team autonomy.
Monolith vs Microservices
A team-topology decision far more often than a technology one.
Organisational Constraints
Team structure, skills and budget cycles as architectural inputs.
Technical Leadership
Setting direction and carrying accountability without a team reporting to you.