APIs, Networking & Integration Topics
API design, management, and integration patterns including REST, GraphQL, and other protocols. Covers API contract design, versioning strategies, error handling, idempotency, deprecation planning, and SDK/integration frameworks. Includes system-to-system integration, webhook patterns, and integration platform considerations. Excludes network infrastructure and network-layer protocols (see Network Architecture under Cloud & Infrastructure or a dedicated networking category if needed).
RESTful API Design and HTTP Fundamentals
Understanding REST architectural principles including resource-based URLs, proper HTTP methods (GET for safe retrieval, POST for creation, PUT for updates, DELETE for deletion), appropriate status codes (200 OK, 201 Created, 400 Bad Request, 404 Not Found, 500 Internal Server Error), and stateless communication patterns. Ability to design simple API endpoints following REST conventions.
Application Programming Interface Design and Integration
Designing Application Programming Interfaces and selecting communication protocols to meet functional and non functional requirements. Candidates should be able to evaluate and choose between Representational State Transfer style resource oriented interfaces, Graph Query Language approaches, remote procedure call frameworks such as Google Remote Procedure Call, and message based or event driven integration patterns. Discussion should cover protocol and format trade offs including latency, throughput, consistency and ordering, binary versus text serialization formats such as protocol buffers or JavaScript Object Notation, developer ergonomics, client diversity, and resource consumption. Core design topics include contract design and schema evolution, versioning and backward compatibility strategies, pagination, filtering, sorting and error handling conventions, authentication and authorization models, rate limiting and quota strategies, caching choices, and gateway or proxy patterns. Integration concerns include direct synchronous calls, asynchronous message based decoupling, event streaming, and web hooks, plus client and server software development kits and data transformation between layers. Candidates should also explain resilience and reliability patterns such as timeouts, retries, circuit breaker and bulkhead techniques, and describe testing, monitoring and observability approaches including logging, metrics and distributed tracing. Finally, discussion should connect API and protocol choices to coupling, scalability, operational complexity, security posture, and developer productivity.
API and Full Stack Coding Patterns
Beyond pure algorithms, be prepared for problems that combine algorithmic thinking with API design, rate limiting, caching strategies, or distributed system concepts. Understanding how a coding solution fits into a larger fullstack architecture.
Data Management and API Design
Designing how applications structure, expose, and consume data through APIs and backend systems. Covers API design principles for data endpoints, pagination, filtering and sorting, idempotency, versioning, rate limiting, schema design, normalization versus denormalization, consistency models, caching strategies, client side fetching patterns, and error handling. Includes considerations for data integrity across integrations, transactional boundaries, master data management, and how API decisions affect downstream consumers and performance.
Service Communication and API Design
Design and specify APIs and interservice communication patterns for systems that must scale. Topics include REST design and best practices, API versioning and deprecation strategies, backward compatibility and API evolution, contract design between services, choosing protocols such as gRPC versus HTTP for internal or external communication, security and authentication patterns at the API level, performance and scalability considerations, observability and monitoring of service interactions, and strategies for evolving interfaces without breaking consumers.
Integration Patterns and API Design
Focuses on integration concepts, data flow, and API design as the foundation for connecting systems and services. Coverage includes data integration techniques such as ETL and ELT, change data capture, data warehousing, synchronization and eventual consistency challenges, latency and throughput considerations, middleware and messaging solutions, and common integration patterns used in marketing and enterprise stacks. For APIs, topics include what APIs are and why they matter for developer products, REST versus GraphQL trade offs and use cases, HTTP methods and semantics, authentication and authorization patterns, rate limiting and throttling, versioning strategies, idempotency and error handling, documentation and developer experience, monitoring and service level considerations, and how API choices affect product and business decisions.
API Integration and System Connectivity
Covers the end to end concepts and practices for connecting systems using application programming interfaces and integration middleware. Candidates should understand REST and HTTP fundamentals, webhooks versus polling, API authentication and authorization patterns, request and response formats, rate limiting, versioning, and reading API documentation. Include practical skills for building and troubleshooting integrations: data mapping and transformation, schema mapping, message formats, error handling and retry strategies, idempotency, logging and monitoring, and ensuring data consistency across synchronous and asynchronous flows. Also includes integration tooling and middleware platforms, real time versus batch synchronization, designing for partial failures and back pressure, and frontend concerns such as async data fetching, loading and error states, pagination, optimistic updates, and race condition mitigation.
Client Performance and Networking
Covers concurrency and performance optimization for client applications, especially mobile and desktop apps. Topics include high level concurrency primitives and patterns such as Grand Central Dispatch, async and await, coroutines, thread safety, race condition prevention, deadlock avoidance, and testing for concurrency bugs. Networking topics include HTTP best practices, connection management, retry and backoff strategies, efficient request serialization, error handling, and use of standard networking libraries and frameworks. Performance concerns include application launch time reduction, memory footprint management, responsiveness and frame rate stability, battery and energy efficiency, and strategies for reducing networking cost and latency. Tooling and measurement include profiling and tracing techniques, using platform profilers and instruments for CPU, memory, and network analysis, capturing and interpreting performance traces, and identifying hotspots to guide optimization efforts. Candidates should be able to explain trade offs between responsiveness, resource usage, and code complexity and propose concrete optimizations and measurement approaches for client scenarios.
API Integration and Networking
Making and managing network requests to external services and third party APIs, including HTTP fundamentals and REST principles. Topics include constructing requests, headers and authentication schemes such as token handling and refresh flows, parsing and serializing JSON, handling HTTP status codes, network error handling, timeout and retry strategies, backoff, offline and caching strategies, security concerns such as HTTPS and certificate pinning, and familiarity with common networking libraries on different platforms. Candidates should demonstrate the ability to integrate external APIs reliably and securely and to reason about networking trade offs.