Top 15 Architecture Interview Questions

Browse 15 real-world technical and behavioral interview questions about Architecture. Review scenarios, edge cases, and architectural best practices.

How do you execute the Inverse Conway Maneuver on a 200-person engineering org that accidentally built a distributed monolith mirroring their dysfunctional silos?

A pragmatic guide to dismantling component teams, breaking database monoliths, and surviving the political fallout of organizational restructuring. Use this engineering leadership answer to show the decision, trade-off, and evidence rather than a memorised definition. It also connects org design to the point an interviewer is testing.

hardscenario

How do you implement local-first collaborative editing without the unbounded memory growth inherent to CRDTs crashing the client?

Assess the candidate's expertise in distributed systems within the browser, focusing on Conflict-free Replicated Data Types, memory optimisation, and peer-to-peer state synchronisation. Use this frontend answer to show the decision, trade-off, and evidence rather than a memorised definition. It also connects architecture to the point an interviewer is testing.

hardscenario

How do you architect and implement Dynamic Feature Modules in an Android application to reduce initial download size and deliver features on demand?

Evaluate the candidate's ability to reduce Android app size and optimise delivery using Dynamic Feature Modules, the Play Core Library, and reversed dependency injection structures. Use this MOBILE answer to show the decision, trade-off, and evidence rather than a memorised definition.

hardscenario

How do you implement a scalable architecture and tooling to automatically enforce strict WCAG 2.1 AA compliance across dozens of autonomous frontend teams without crippling developer velocity?

Assess the candidate's capability to shift accessibility left through automated enforcement pipelines, inherently accessible design systems, and systemic remediation strategies at scale.

hardscenario

How do you design a highly available envelope encryption architecture that protects billions of records without exhausting KMS API limits or crushing latency?

Envelope encryption at scale separates Data Encryption Keys (DEKs) from Key Encryption Keys (KEKs), caches plaintext DEKs only inside strict boundaries, and designs rotation so latency, KMS limits, and algorithm migration do not break availability.

hardscenario

Would you deploy LoRA adapters or a Mixture of Experts (MoE) architecture to serve hundreds of highly specialised enterprise domains from a single foundation model, and why?

An analysis of the cost, performance, and complexity trade-offs between LoRA fine-tuning and MoE architectures for multi-tenant domain adaptation. Use this cost optimization answer to show the decision, trade-off, and evidence rather than a memorised definition. It also connects finetuning to the point an interviewer is testing.

hardscenario

You're asked to break up a five-year-old iOS app that has become one enormous Xcode target - how would you approach modularising it, and what does it cost you?

Modularising means carving the app into Swift packages along feature and layer boundaries so build graphs and ownership become explicit, at the cost of slower initial builds, careful dependency direction, and real discipline about what each module exposes publicly. Use this IOS answer to show the decision, trade-off, and evidence rather than a memorised definition.

harddesign

How do you design the dependency graph, handle shared resources, and optimise build times when breaking down a massive iOS monolithic application into a modular architecture using Tuist?

Assess the candidate's ability to migrate a large-scale iOS application to a modular architecture using Tuist, managing dependency graphs, enforcing architectural boundaries, and optimising build times. Use this MOBILE answer to show the decision, trade-off, and evidence rather than a memorised definition.

hardscenario

How do you leverage WorkManager to guarantee execution, handle conflict resolution, and optimise battery usage in an offline-first Android application requiring bidirectional synchronisation?

Evaluate the candidate's understanding of offline-first principles, background processing using Android's WorkManager, conflict resolution strategies, and battery optimization techniques. Use this MOBILE answer to show the decision, trade-off, and evidence rather than a memorised definition.

hardscenario

How do you resolve severe performance bottlenecks in a complex React Native application caused by heavy bridge traffic, and how do you evaluate a migration to the JavaScript Interface (JSI)?

Assess the candidate's understanding of the React Native architecture, bridge performance limitations, profiling techniques, and modern solutions like JSI and the New Architecture. Use this MOBILE answer to show the decision, trade-off, and evidence rather than a memorised definition. It also connects cross platform to the point an interviewer is testing.

hardscenario

How do you safely rebuild a corrupted read model in an event-sourced architecture without incurring significant downtime?

Rebuild a corrupted CQRS read model by replaying the event store into a fresh projection, applying upcasters for old event versions, validating parity, and cutting over with a blue-green deployment.

hardscenario

How do you prevent a distributed frontend from becoming a single point of failure when remote modules inevitably crash or timeout?

Assess candidate's ability to architect fault-tolerant micro-frontends, manage distributed dependencies, and implement robust error handling in a Module Federation setup.

hardscenario

How do you architect a React Server Components migration without accidentally forcing the entire component tree back to the client?

React Server Components differ from SSR because they keep server-only work out of the client bundle instead of only rendering HTML on the server. The migration works when the use client boundary stays low and data fetching stays on the server.

hardscenario

When is an agent the wrong shape for a problem?

Whenever you can draw the flowchart. A fixed pipeline with a model at the two steps needing judgement is cheaper, testable and debuggable, and per-step error compounds across a planning loop. Reach for an agent when the tool sequence is open-ended and the environment verifies the work.

harddesign

Would you rely on VPNs and static credentials, or how do you architect a Zero Trust identity system for a globally distributed workforce accessing highly sensitive cloud workloads?

Assessing the architectural transition from legacy perimeter models to Zero Trust, focusing on continuous authentication, context-aware access, and the elimination of static credentials. Use this security answer to show the decision, trade-off, and evidence rather than a memorised definition. It also connects cloud security to the point an interviewer is testing.

hardscenario