Demonstrate strong practical knowledge of a backend programming language such as JavaScript with Node dot js, Python, Java, Go, or similar. Cover language fundamentals, idiomatic usage, standard library features, package and dependency management, common frameworks and ecosystem tools, testing strategies and tooling, error handling and observability, and patterns for maintainable server side code. Be ready to explain concurrency and asynchronous models in the language, performance considerations, security best practices, deployment and packaging approaches, and examples of backend services or APIs you built including trade offs and chosen libraries.
MediumSystem Design
39 practiced
Design a REST API endpoint in Java Spring Boot for paginated product listings that supports both offset and cursor pagination. Define query parameters, response payload structure (items, meta, next cursor), and outline the SQL queries or indices needed for efficient cursor pagination. Discuss the tradeoffs of offset versus cursor for large datasets.
HardTechnical
45 practiced
During a code security review you find potential SQL injection across services in Java, Python, and Go client libraries. Describe how to safely reproduce the issue in a test environment, and give language-specific fixes (e.g., PreparedStatement for Java, parameterized queries for Python DB-APIs, parameterized queries for Go database/sql), plus remediation and monitoring steps.
HardTechnical
44 practiced
Discuss pros and cons of reflection or heavy metaprogramming in backend systems (Java reflection, Python metaclasses). Cover performance overhead, type safety and tooling, security implications, runtime errors, testability, debugging difficulty, and alternatives like code generation or compile-time macros.
MediumBehavioral
31 practiced
Tell me about a time you introduced a new backend language feature, library, or pattern to your team that improved code quality, performance, or developer productivity. Use the STAR format: Situation, Task, Action, Result. Describe the technical tradeoffs, how you persuaded stakeholders, and what metrics or outcomes demonstrated success.
MediumTechnical
55 practiced
Explain Java's try-with-resources, Python's context managers using with, and Go's defer statement for resource cleanup. Provide brief code examples and discuss when each guarantees cleanup (including exception paths), how nested resources behave, and common pitfalls to avoid in a long-running backend service.
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