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 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 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.
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.
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.
Solution Architecture and System Integration
Designing end to end solutions that integrate multiple systems and services. Topics include API design and compatibility, protocol choices, data flow and transformation, middleware and orchestration, handling partial failures and eventual consistency, versioning and backward compatibility, and non functional requirements such as performance and security. Emphasis on mapping business requirements to technical solutions and integration strategies.
API and Interface Design
Design clear and composable Application Programming Interfaces and public interfaces for services and libraries. Cover specifying inputs, outputs, error signaling, versioning, backward compatibility, authentication and authorization, rate limiting and throttling, pagination and filtering, and schema design. Emphasize idempotency, client ergonomics, documentation and contract testing, monitoring and observability hooks, and when to avoid premature optimization or over engineering.
Custom Solution Architecture
Evaluates ability to design bespoke technical solutions that integrate a platform with customer systems. Topics include integration patterns for synchronous and asynchronous data exchange, data flows and transformation, identity and access management, secure connectivity and encryption, schema and contract management, scaling and partitioning to meet customer volume, error handling and idempotency, phased implementation and migration plans, testing and validation approaches, monitoring and operational readiness, and cost and compliance considerations.