Senior iOS questions
Senior iOS Interview Questions
Questions matter less than the structure used to answer them. These prompts reveal whether your judgment is calibrated.
Short answer
What matters most
Senior iOS interview questions usually test tradeoffs rather than definitions. Expect prompts about state ownership, UIKit and SwiftUI interoperability, async task lifetime, memory behavior, persistence, networking, testing, app performance, modularization and production incidents. Answer by clarifying the context, stating a default choice, comparing the nearest alternative, naming failure modes and explaining what evidence would change your decision. Use a concrete example when possible. Avoid universal claims such as always use SwiftUI or actors make code thread-safe. A credible senior answer shows where a tool works, where it stops working and how the team would detect a bad assumption after release.
Platform and architecture prompts
Practice questions that force boundaries to become explicit.
- How would you migrate a large UIKit flow to SwiftUI?
- Who should own navigation and long-lived state?
- When would you avoid a shared repository?
- How do you keep a modular app from becoming a dependency graph problem?
- What changes when two scenes show the same data?
Concurrency and performance prompts
Explain the timeline, not only the API.
- What can change across an await?
- How do you prevent stale search results?
- Why can an actor-protected workflow still be wrong?
- How would you diagnose a slow launch?
- When is caching making performance worse?
Production and leadership prompts
Prepare an incident you helped resolve, a decision you reversed and a disagreement that improved the result. The answer should separate facts from your interpretation and make your individual contribution clear.
End with the mechanism you changed afterward. Senior engineers do not only fix the incident. They reduce the chance that the same class of incident returns.
