Search the practice set
126 questions, 454 terms and 400 topics in 20 areas.
60 results for “Cloud Migration”
Migration Wave
A batch of applications migrated together, sequenced so that dependencies move in a workable order and each wave delivers learning for the next.
Six Rs of Migration
The standard menu of options for each application in a migration — rehost, replatform, refactor, repurchase, retire, retain.
Slack's Cellular Migration
After repeated availability-zone-level incidents, Slack rebuilt its infrastructure into per-zone cells with the ability to drain traffic away from a failing zone in minutes.
Application Discovery
Establishing what applications exist, what they depend on, who owns them and whether anyone uses them — the step whose absence makes every later step a guess.
Capital One's Data Centre Exit
A major US bank closed all eight of its data centres and moved fully to public cloud, treating governance automation as the enabling technology rather than a constraint.
Replatform
Migrating an application largely as-is while making targeted changes to exploit the target platform — usually the best return per unit of effort.
Airbnb's Service-Oriented Migration
Airbnb decomposed a large Rails monolith by first extracting a unified data-access layer, so that services were built on owned data rather than on shared database tables.
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.
Cloud Pricing Models
The purchase options for cloud compute — on-demand, committed use, and spot — which differ by up to 90% for identical hardware.
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.
Virtual Private Cloud
A logically isolated network inside a cloud provider, with an address range you control and explicit rules for what may enter and leave.
Zero-Downtime Migration
Changing a schema or system while it stays in service, by adding the new alongside the old, migrating, then removing the old.
Account Vending
Automated creation of new cloud accounts pre-configured with the organisation's networking, identity, logging, guardrails and cost allocation.
Autoscaling
Adding and removing capacity automatically in response to a demand signal, to track load without paying for peak all the time.
Availability Zone
One or more physically separate data centres inside a cloud region, with independent power, cooling and network, connected by low-latency links.
Backup Strategy
A plan for what is copied, how often, where to, how long it is kept, and — the part that decides whether it is real — how the restore is verified.
Blast Radius
The set of things that break, or become reachable, when one component fails or is compromised.
Blast Radius Reduction
The set of deliberate partitions — accounts, regions, zones, cells, tenants, deployment stages — that bound how far any single failure or compromise can reach.
Block Storage
A virtual disk attached to one instance at a time, presented as raw blocks and formatted with a filesystem — the storage databases and stateful workloads run on.
CDC Initial Snapshot
The consistent full copy taken when a CDC pipeline starts, before streaming begins — and the step that determines whether the target is correct.
Chargeback and Showback
Attributing cloud cost to the teams that generate it — either informationally (showback) or by moving it onto their budget (chargeback).
Connection Proxy
A pooling layer between applications and a managed database that multiplexes many client connections onto a small number of database connections.
Control Plane and Data Plane
The separation between the machinery that makes changes to a system and the machinery that serves its traffic.
Cross-Zone Data Transfer
Charges incurred when data moves between availability zones within a region — invisible on architecture diagrams and a recurring surprise on cloud bills.
Dual Write
Writing the same change to both the old and new stores during a migration, and the reconciliation that makes it trustworthy.
Durability vs Availability
Two different storage guarantees — whether data survives, and whether it can be reached right now — routinely conflated because both are quoted in nines.
Egress Cost
The charge for moving data out of a cloud provider or across its zones and regions — usually the least-anticipated line on a cloud bill.
You are asked to lead a migration of 300 applications to cloud. What happens in the first ninety days?
Days 1–30: discovery, and the foundation in parallel Discovery from evidence, not interviews. Network flow logs for dependencies (the only trustworthy source),
An estate has database passwords in environment variables across 200 services. Design the migration to a secrets manager.
Sequence it by risk, not by convenience Phase 0 — stop the bleeding. Secret scanning in CI and on the existing repositories, blocking new commits containing cre
An organisation is starting cloud adoption. Three teams want to deploy next month. What must exist first, and what can wait?
What must exist before anything reaches production Account structure. Separation by environment and by workload, because an account is the strongest isolation b
Design the network layout for a three-tier application in one cloud region. What are the decisions you cannot easily change later?
What the interviewer is testing Whether you know which network decisions are cheap and which are effectively permanent. This is a knowledge question with a clea
Finance wants to cut cloud spend by committing to one-year and three-year reservations. What do you commit to, and what could go wrong?
What the interviewer is testing Whether you can turn a blunt cost mandate into a portfolio decision with a stated risk, rather than either refusing it or over c
TSB's 2018 core banking migration moved 1.9 million customers in a single weekend and failed publicly. What would you have required before approving that cutover?
The case, as publicly reported In April 2018 TSB migrated from a platform rented from Lloyds Banking Group to Proteo4UK, built by its parent Banco Sabadell. The
The cloud bill has tripled in six months while traffic grew 40%. How do you find out why, and what do you expect to find?
What the interviewer is testing Whether you approach cost with the same rigour as latency, and whether you know where cloud money actually goes. How to find out
You are asked to choose between a cloud data warehouse and a lakehouse for a new analytics platform. How do you decide?
What actually differs The gap has narrowed considerably, so the decision turns on fewer things than the marketing suggests. Format ownership. In a lakehouse, da
A DR test fails: the secondary region cannot launch enough instances. What happened, and what standing checks prevent it?
What happened Service quotas in the secondary region are far lower than in the primary , because nothing has ever run there at scale. Quotas are per account and
A serverless API works in testing and fails under load with connection errors. The database is at 5% CPU. Explain and fix.
The mechanism Serverless functions scale by creating independent execution environments , each with its own process and its own connection pool. Two hundred con
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 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
Choose storage for four workloads: a Postgres data directory, user-uploaded images, a shared build cache, and seven years of audit records.
Postgres data directory — block storage It needs low latency random reads and writes and a filesystem, and it attaches to one instance. That is precisely block
Cloud Migration
Per-application disposition, sequencing and the capability change underneath.
Cloud Architecture
General material on designing for cloud platforms.
Cloud Databases
Managed relational, key-value, document and analytical services.
Cloud Governance
Preventive policy, tagging, quotas and cost and security guardrails.
Cloud Pricing Models
On-demand, committed and spot, and the crossover arithmetic.
Cloud Storage
Object, block and file storage, and the access patterns each suits.
Data Migration Strategies
Backfill, dual-write, reconciliation and verification.
Database Migration
Moving engines, versions and schemas without losing data or uptime.
Migration Risk
Bounding blast radius, staging by cohort, and honest readiness reporting.
Multi-Cloud
Best-of-breed, portfolio and portable — three very different costs.
Zero-Downtime Migration
Expand, migrate, contract — and the contract phase that never happens.
Autoscaling
Signals, delays and bounds — and the maximum that caps a runaway bill.
Availability Zones
The unit of correlated physical failure, and what zones do not protect against.
Backup Strategies
Scope, immutability, separation, and the restore drill that makes it real.
Compute Models
Instances, containers and functions, and what each is priced and shaped for.
Containers
Images, registries, immutability and the deployment model they enable.
Disaster Recovery
Backup-restore, pilot light, warm standby and active-active postures.
Edge Computing
Moving compute towards the user, and what cannot follow it.