Security & performance interview practice.
Rehearse with explained interview questions. Describe the mechanism, trace an example, and explain a trade-off before revealing the answer.
How to use this session
- Choose a level and session length. Try each prompt before opening the notes.
- Compare your explanation with the source answer and revisit any concept you missed.
- Mark the questions you reviewed. Sign in to save session history; your draft answers stay in this page.
Code is provided for reading and tracing. These sessions do not execute or automatically grade code.
Security & performance practice
Think first. Reveal second.
Explain your reasoning before opening the notes. A focused session lets you choose your question count; mock rounds follow the original guide.
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Preview the Security & performance question pool
- What do Big-O and profiling tell me?
Big-O describes how an algorithm's work or memory grows as the input grows. Profiling measures where a particular application spends time or retains memory during a real workload. They complement each other: growth rate explains future scaling, while profiling locates the current bottleneck.
- How do I identify the slow part of an API?
API latency is the total time a request spends waiting and doing work across the system. That time can include load-balancer delay, connection-pool wait, application CPU, database work and external calls. Breaking it into stages turns “the API is slow” into a testable explanation.
- When should I use pagination, streaming, compression or a CDN?
Pagination, streaming, compression and CDNs reduce different costs of moving data. Pagination returns fewer records, streaming avoids buffering the full payload, compression sends fewer bytes, and a CDN shortens the route for reusable content. Choosing the right technique requires knowing whether the problem is volume, memory, bandwidth or distance.