Programming Languages & Core Development Topics
Programming languages, development fundamentals, coding concepts, and core data structures. Includes syntax, algorithms, memory management at a programming level, asynchronous patterns, and concurrency primitives. Also covers core data manipulation concepts like hashing, collections, error handling, and DOM manipulation for web development. Excludes tool-specific proficiency (see 'Tools, Frameworks & Implementation Proficiency').
Concurrency and Synchronization
Covers the principles and practical techniques for safely coordinating concurrent execution and access to shared resources. Topics include models of concurrency such as threads, processes, interrupt handlers, and tasks in a real time operating system; differences between preemptive and cooperative scheduling; shared data hazards including race conditions and read modify write hazards; critical sections and approaches to protect them including disabling interrupts in embedded contexts and scoped locks. Synchronization primitives and patterns are included: mutexes, binary semaphores, counting semaphores, condition variables, message queues, atomic operations and lock free primitives such as compare and swap. Memory ordering concerns and memory barrier usage on multi core systems are covered, along with priority inversion and priority inheritance. Also addressed are deadlock, livelock, and starvation concepts and avoidance strategies, granularity and performance trade offs of locking, and practical synchronization patterns. Preparation should include identifying and fixing races in code, designing correct concurrent interfaces, and debugging and testing techniques such as stress testing, instrumentation, deterministic replay, race detectors, static analysis, and code review strategies.
Swift Language and Memory Management
Deep understanding of Swift syntax, type system, ARC (Automatic Reference Counting), weak/strong references, and avoiding retain cycles. Understanding of value types vs reference types and when to use each. Familiarity with modern Swift features like async/await, property wrappers, and generics.
Debugging and Code Optimization
Practical debugging skills and techniques for improving code performance and complexity. Topics include tracing and reproducing bugs, stepping through execution, reasoning about time and space complexity, refactoring for performance, and applying algorithmic optimizations. Candidates should be able to demonstrate logical debugging approaches and make safe, measurable performance improvements to working code.
Systems Programming & Low-Level Concepts
Systems programming concepts including memory management, pointers, memory layout, CPU architecture considerations, concurrency primitives, OS interactions, and performance optimization in low-level languages (C, C++). Covers how languages expose low-level resources, toolchains, and platform-specific behaviors; excludes high-level application development.
Object Oriented Design Principles
Technical principles for designing object oriented systems that are maintainable, extensible, and testable. Topics include single responsibility, open closed, Liskov substitution, interface segregation, and dependency inversion principles; composition versus inheritance trade offs; designing clear and minimal public interfaces and application programming interfaces; separation of concerns, low coupling and high cohesion; use of design patterns where appropriate; strategies for dependency management and dependency injection; and practices that improve testability such as designing for mocking and modularity. Interviewers evaluate ability to reason about class and module boundaries, extensibility, performance and complexity trade offs, and to produce clean code and APIs that support long term maintenance.
Error Handling and Defensive Programming
Covers designing and implementing defensive, fault tolerant code and system behaviors to prevent and mitigate production failures. Topics include input validation and sanitization, null and missing data handling, overflow and boundary protections, exception handling and propagation patterns, clear error reporting and structured logging for observability, graceful degradation and fallback strategies, retry and backoff policies and idempotency for safe retries. Also address concurrency and synchronization concerns, resource and memory management to avoid exhaustion, security related input checks, and how to document and escalate residual risks. Candidates should discuss pragmatic trade offs between robustness and complexity, show concrete defensive checks and assertions, and describe test strategies for error paths including unit tests and integration tests and how monitoring and operational responses tie into robustness.
Python Programming & ML Libraries
Python programming language fundamentals (syntax, data structures, control flow, error handling) with practical usage of machine learning libraries such as NumPy, pandas, scikit-learn, TensorFlow, and PyTorch for data manipulation, model development, training, evaluation, and lightweight ML tasks.
IOS Development Fundamentals (Swift/Objective C)
Core iOS concepts including UIView/SwiftUI architecture, view controller lifecycle, memory management (ARC), delegates and protocols, notifications, KVO, and common frameworks (Foundation, UIKit). Understanding of Swift language features relevant to iOS development.
Bitwise Operations and Bit Manipulation
Covers working with binary representations of integers and performing fundamental bitwise operations including and, or, xor, not, and left and right shifts. Includes techniques for testing setting clearing and toggling individual bits, creating and applying masks, and using bit fields and bit packed structures for compact storage. Addresses endianness and byte order considerations, bit level register manipulation for hardware and embedded systems, and efficient bit algorithms such as population count parity leading and trailing zero detection and sign extension. Encompasses practical uses in protocol parsing flag management performance optimizations and cryptographic primitives including substitution and diffusion concepts. Candidates may be assessed with coding problems that require bit tricks and algorithmic reasoning as well as design questions about data layout and low level interfaces.