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).
Application Programming Interface Security and Architecture
Design and implementation of secure application programming interfaces and service interfaces, covering architecture, design patterns, and operational controls across monoliths, microservices, and service mesh environments. Topics include authentication and authorization patterns for endpoints such as OAuth two, application programming interface keys, and JavaScript Object Notation Web Tokens; token and key lifecycle and secure storage; mutual Transport Layer Security for service to service authentication; gateway and proxy based controls and hardening; input validation, schema and contract validation, output encoding, parameter filtering, and secure error handling to prevent injection, parameter pollution, and excessive data exposure. Also covers rate limiting, throttling, and anomaly detection to mitigate abuse and credential stuffing; secure transport and encryption in transit and at rest; design of internal versus external trust boundaries; application programming interface discovery and inventory; threat modeling and mitigations for common application programming interface attacks; and operational practices including audit logging, monitoring, alerting, automated security testing, continuous validation, and strategies for scaling security across many endpoints and services.
Application Programming Interface Design and Scalability
Designing application programming interfaces that remain reliable, performant, and maintainable at high scale. Candidates should understand how interface decisions affect scalability, availability, latency, and operational complexity and be able to reason about trade offs between client complexity and server responsibility. Core areas include stateless interface design, pagination and cursor strategies for large result sets, filtering and search optimization, payload minimization, batching and streaming, and techniques to reduce server load while preserving client experience. Resilience and operational controls include rate limiting and quota management, throttling, backpressure and flow control, retry semantics and idempotency patterns, error format design and explicit identification of retryable errors, and strategies for graceful degradation under overload. Evolution and compatibility topics include backward compatible versioning strategies, deprecation policies, contract design and testing approaches to avoid breaking consumers. Infrastructure and deployment considerations include API gateway and edge patterns, interaction with load balancers and traffic distribution, caching and content delivery, routing fault tolerance, health checks and canary rollout strategies, and observability through metrics, distributed tracing, and logging to support capacity planning and incident response. Security considerations such as scalable authentication and authorization, credential and key management, and permission models are also important. Candidates should be prepared to discuss concrete patterns, trade offs, algorithms, and operational playbooks for designing and running high traffic application programming interfaces.
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.
RESTful API Design
Focuses on designing resource oriented web APIs following Representational State Transfer principles and proper use of the Hypertext Transfer Protocol. Core skills include resource modeling and endpoint naming, use of correct Hypertext Transfer Protocol methods and semantics, status code selection and error response structure, idempotency and stateless design, request and response formats such as JavaScript Object Notation, pagination, filtering and sorting strategies, versioning and backward compatibility, authentication and authorization patterns, rate limiting and abuse prevention, caching and performance considerations, API contract testing and documentation, common anti patterns, and designing APIs that balance client usability with backend implementation concerns.
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.
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.
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.
Frontend Backend Integration Through APIs
Understanding how frontend components interact with backend APIs using HTTP requests (fetch, axios, etc.), handling asynchronous responses and errors, managing data flow from API responses to UI updates. Ability to design APIs that frontend needs and implement corresponding client-side code to consume them properly.
Application Programming Interface Design and Communication
Test the candidates ability to design clean application programming interfaces that are intuitive for clients and to clearly explain the design and its trade offs. Coverage includes resource and contract design, request and response formats, error handling and status conventions, versioning and backward compatibility, performance considerations, rate limiting and security basics, and selection of synchronous versus asynchronous communication approaches. At senior levels this expands to event driven patterns, message based systems, gateway patterns, and how interface decisions affect downstream systems and reliability.