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 Design and Strategy
Covers the design, developer experience, and strategic operating decisions for Application Programming Interfaces and developer platforms. Candidates should demonstrate core design principles such as simplicity, consistency, discoverability, clear naming and conventions, intuitive resource modeling, robust error handling, stability, backward compatibility, and explicit versioning strategies. They should understand trade offs among interface paradigms including Representational State Transfer style APIs, Graph Query Language approaches, and remote procedure call frameworks such as gRPC, and how those choices affect discoverability, latency, schema evolution, client ergonomics, testing, and mocking. The topic also includes the developer facing surface area beyond the interface itself: documentation, quickstart guides, sample code, software development kits, command line tools, interactive explorers, sandbox environments, and other onboarding artifacts that reduce friction. Candidates should be able to identify common friction points such as unclear documentation, complex setup and authentication flows, unhelpful error messages, inconsistent or surprising behaviors, slow feedback loops, and endpoints that are hard to mock or test, and propose concrete engineering and process solutions. Measurement and optimization expectations include onboarding and adoption metrics such as time to first successful call, time to first meaningful result, onboarding success rates, developer satisfaction and sentiment, adoption and churn, support and integration costs, error rates and latency, and how to instrument and monitor the developer journey. Engineering practices to discuss include stable contract design, semantic versioning and compatibility guarantees, schema and contract testing, clear deprecation policies, monitoring and observability for developer journeys, automated client generation and migration tooling, authentication and rate limiting strategies, webhook and event mechanisms, and monetization or partnership models for platform growth. Senior candidates should connect technical and experience decisions to product and business outcomes, explaining how design choices drive adoption, reduce support load, enable ecosystem growth, and preserve long term platform velocity, and should provide concrete examples of improvements implemented or proposed and how their impact was measured.
Developer Documentation and Tools
Covers the full scope of developer experience around a technical platform, including platform stability, API documentation, developer tooling, and software development kits. Candidates should be prepared to discuss endpoint documentation patterns, request and response examples, error handling guidance, authentication and authorization documentation, rate limiting and quotas, and migration and changelog management. Include practical aspects such as code samples in multiple languages, example applications, SDK design and maintenance, developer testing tools, and integrations with modern documentation toolchains like OpenAPI and GraphQL schemas. Also cover how documentation quality and developer tools affect adoption and support burden, metrics for measurement such as search success rate and example usage, strategies for keeping examples current, versioning and backward compatibility challenges, and holistic approaches to improving developer experience beyond API design.
Migrations, Versioning & Compatibility at Scale
Understand how to design systems that support long-term evolution while maintaining compatibility. Discuss strategies for API versioning, gradual deprecation of old versions, and migration paths for customers. Be able to discuss how to maintain backward compatibility while evolving a system, and trade-offs between maintaining multiple versions versus forcing migrations. For large platforms, discuss how to coordinate migrations across thousands of dependent systems.
Application Programming Interface Design and Rate Limiting
Focuses on designing scalable application programming interfaces that handle high request volumes while protecting infrastructure and preserving developer experience. Topics include API surface design and versioning, idempotency and retry semantics, authentication and authorization impacts, consistency and backward compatibility, and choosing protocols and payload formats. For scaling and protection discuss rate limiting and quota strategies such as token bucket, fixed window, sliding window, leaky bucket, per API key and per user limits, and hierarchical quotas. Cover backpressure, graceful degradation, circuit breakers, throttling responses and headers that communicate limits to clients, retry guidance, and strategies to avoid thundering herd effects. Also include operational concerns: monitoring and observability for request and error rates, metrics for usage and latency, metering and billing implications for usage based pricing, developer platform experience, documentation and developer tooling, testing at scale, and trade offs between strict protection and usability.
Developer Experience and API Product Thinking
Focuses on designing products and platforms where the primary users are developers or engineering teams. Key areas assessed include developer onboarding, API design and usability, documentation and example code, developer tooling and SDKs, error diagnostics and observability, and developer support workflows. Candidates should be able to reason about how developer experience affects adoption, retention, time to first success, developer productivity, and downstream business metrics. Interview discussions may include making trade offs between API ergonomics and system constraints, designing developer contracts and versioning strategies, measuring developer satisfaction and success, integrating feedback loops from developer users, and aligning developer platform roadmaps with platform reliability and security goals. For platform and infrastructure products explore how to prioritize features for internal versus external developers, how to run research and experiments with small developer populations, and how to craft documentation, samples, and onboarding flows that reduce friction.
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 Design and Integration
Design and evaluate application programming interfaces for external and internal consumption. Topics include resource and schema modeling for RESTful APIs, GraphQL schema and resolver design for diverse clients, and when to choose gRPC style remote procedure calls for high performance internal services. Candidates should address consistent error responses including problem details, pagination and filtering strategies, versioning and deprecation plans, idempotency keys and safe retry semantics, rate limiting headers and status codes, authentication and authorization patterns, contract testing, monitoring and observability, and how to balance backward compatibility with iteration velocity.