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

92 questions in Legacy Modernization.

Quiz

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?

Review this plan. Eighteen months to rebuild the policy engine. Feature parity is required before any traffic moves. The legacy team is frozen to bug fixes only so that no effort is wasted on code that will be thrown away. What would you remove, what would you change, and what would you leave alone?

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?

Figma's database stack grew roughly 100x between 2020 and 2024. Rather than shard, the team first moved groups of related tables onto their own databases, and only later sharded horizontally. What did the cheaper structural change buy, what did it leave untouched, and when does that bill arrive?

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?

A data-centre exit must move about 600 virtual machines in nine months. The first wave moved 40 machines chosen because they were the least busy and three business applications became unusably slow overnight. What should decide which machines travel in the same wave?

A data-centre lease expires in eleven months and will not be renewed. The team plans to rehost about 300 virtual machines with no application changes. Which benefit is the one rehosting reliably delivers and therefore the one the plan should be justified on?