Quiz

2627 questions of the kind that actually get asked — in interviews, in architecture review boards, and by the person who has to run the thing at 3 AM. Every answer states the trade-off rather than the slogan, and says when the obvious choice is the wrong one.

All areas2627 Architecture Fundamentals81 Distributed Systems101 Data Architecture90 Cloud Architecture77 Networking86 API & Integration Architecture78 Reliability & Resilience88 Observability81 Performance & Capacity Engineering90 Security Architecture85 Cost Architecture & FinOps82 Business Architecture93 Architecture Communication91 Enterprise Architecture91 Legacy Modernization82 AI-Era Architecture86 Software Architecture & Engineering84 Architecture Patterns84 Architecture Decision-Making91 The Architect's Meta-Skills92 Delivery & Release Engineering93 Platform Engineering & Developer Experience92 Testing & Quality Architecture90 Data Platform Architecture88 Streaming & Real-Time Data93 Data Governance & Semantics81 Frontend & Experience Architecture91 Edge, Mobile & IoT88 Regulatory & Data Protection Architecture90 Assurance, Audit & Model Risk88

Difficulty Any beginner intermediate advanced

53 questions in Legacy Modernization.

Quiz

A legacy system has no clean boundaries to extract — one shared database, entangled modules, no tests. What is the first move, and in what order should capability be recovered?

A platform decomposes a monolith into services. Which boundaries should be extracted first, and which extraction produces a distributed monolith?

During a monolith decomposition, the new search service needs data owned by five other services. What do you do?

How would you identify where to split a large application, using evidence rather than opinion?

A migration will take eighteen months, during which old and new systems both serve production. How should the coexistence period be designed?

During a multi-year migration, old and new systems must coexist. Which coexistence patterns are sustainable and which accumulate debt?

Eighteen months into a coexistence period, customer records are authoritative in the new system and order records are still authoritative in the old one. A refund credits the customer and cancels the order line. What happens the first time the credit commits and the cancellation is rejected?

Your cutover plan says switch reads, then switch writes, then decommission. A reviewer asks what happens at 02:00 if the new store turns out to be wrong after writes have moved. What mechanism makes the write switch reversible, and what is the honest unavailability window?

Alibaba Cloud reported a peak of 583,000 orders per second during Singles' Day on 11 November 2020. Your own platform is far smaller but its annual peak is roughly 40 times a median day and its date is known a year in advance. How does that one fact reshape an eighteen-month migration plan?

A platform must migrate very large volumes of file data between storage systems. Which strategies apply, and what dominates the schedule?

A shipping platform must migrate years of order and tracking data to a new store. What strategy handles both the historical bulk and the ongoing changes?