Technical practice
How would you package a reusable biometric SDK for both iOS and macOS?
What to coverSuggestion: Compare XCFramework, Swift Package Manager and CocoaPods in terms of distribution, dependencies and integration effort. Explain how you would verify that sample applications can consume each release.
How would you design public APIs and versioning for an SDK that supports several biometric capabilities?
What to coverSuggestion: Discuss stable interfaces for face, fingerprint, iris, palm and liveness features without exposing unnecessary implementation details. Address documentation, compatibility and how an API change would be communicated.
How would you choose and optimize a model runtime for on-device inference on Apple platforms?
What to coverSuggestion: Compare Core ML, ONNX Runtime, TensorFlow Lite and PyTorch Mobile based on model compatibility, measured performance and integration cost. Explain when Apple Neural Engine, Metal or Accelerate might help, while treating device-specific results as something to benchmark.
How would you build a real-time camera-to-inference pipeline?
What to coverSuggestion: Walk through capture, image processing and inference using relevant options such as AVFoundation, Vision, Core Image and OpenCV. Discuss frame handling and the trade-off between image quality and end-to-end latency.
How would you evaluate a change to a biometric, OCR or liveness feature before shipping it in an SDK?
What to coverSuggestion: Describe representative input tests, correctness checks and comparisons against the current release for the feature at hand. Include latency and failure cases alongside output quality rather than assuming one metric establishes production readiness.
How would you diagnose an SDK that meets inference targets but slows its host application?
What to coverSuggestion: Separate model execution from camera processing, memory allocation and multithreading effects when profiling. Explain how you would weigh latency improvements against memory use, battery consumption and overall application performance.
How would you protect sensitive data and SDK communications on iOS and macOS?
What to coverSuggestion: Explain the distinct roles of Keychain, Secure Enclave, CryptoKit and certificate pinning where applicable. Discuss what jailbreak detection and anti-tampering can mitigate, without treating either as an absolute guarantee.
What would an automated test and release strategy for a production biometric SDK include?
What to coverSuggestion: Cover API and integration tests, repeatable benchmarks, profiling and CI/CD checks before release. Explain how you would detect performance regressions as well as functional failures.
How would you manage Swift, Objective-C and C++ boundaries in a reusable Apple-platform SDK?
What to coverSuggestion: Discuss where interfaces should sit and how you would handle data ownership, error propagation and maintainability across language boundaries. Relate the choices to stable public APIs and integration by SDK consumers.
How would you maintain feature parity between iOS and macOS without ignoring platform differences?
What to coverSuggestion: Identify which SDK behavior and public contracts should remain consistent, then test platform-specific camera, processing and model-execution paths separately. Explain how you would assess and document a justified difference.
Behavioural practice
Tell me about a time you coordinated model integration across engineering teams.
What to coverSuggestion: Set out the situation and each team's responsibilities, then describe the actions you took to resolve an integration issue with AI, embedded, SDK or platform counterparts. Finish with the observable result and what you learned.
Tell me about a time you improved performance without compromising another important constraint.
What to coverSuggestion: Describe the starting latency, memory, battery or application-performance problem and how you measured it. Explain your action, the trade-off you made and the measured result.
Tell me about a time testing or profiling changed a release decision.
What to coverSuggestion: Describe the release situation, the evidence you found and your role in deciding what to fix or defer. State the result, including how the issue was verified or communicated.
Tell me about a time you had to change a public API used by other developers.
What to coverSuggestion: Explain the original constraint, the options you considered and how you handled compatibility, documentation or versioning. Describe the outcome for developers using the API.
Tell me about a time you handled a feature discrepancy across platforms.
What to coverSuggestion: Describe the expected behavior, the difference you found and how you worked with others to decide whether parity was feasible. Explain your action and the resulting behavior or documented limitation.