Quiz

2667 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 areas2667 Architecture Fundamentals81 Distributed Systems101 Data Architecture90 Cloud Architecture87 Networking86 API & Integration Architecture78 Reliability & Resilience88 Observability81 Performance & Capacity Engineering90 Security Architecture95 Cost Architecture & FinOps92 Business Architecture93 Architecture Communication91 Enterprise Architecture91 Legacy Modernization92 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

56 questions in Legacy Modernization.

Quiz

A financial calculation engine is being replaced and the results must be proven equivalent before cutover. How should a parallel run be designed, and how are discrepancies triaged?

A logistics platform is replacing its core routing system. Should it run the old and new systems in parallel, and for how long?

You are reimplementing a legacy capability. What does running old and new in parallel find that testing cannot?

A 15-year-old system is unmaintainable. The team wants a full rewrite. What do you advise?

A platform's core system cannot support a capability the business needs. The team proposes a rebuild. What must be true for rebuild to beat incremental re-architecture?

An organisation running Kafka at trillions of messages per day concludes the coordination and rebalancing model no longer fits and builds a replacement. What evidence should exist before replacing a proven system rather than tuning it?

A high-change application is constrained by its structure. What distinguishes refactoring from re-architecting here, and how do you choose?

A team proposes rewriting a critical system from scratch, arguing the existing one is unmaintainable. How do you evaluate this?

Six months into a two-year re-architecture you become convinced the target architecture is wrong. Walk me through how you raise it and what you propose.

When would you re-architect rather than replatform, and how would you sequence it?

You have twelve weeks and a large estate. Which replatforming changes do you make and why those?