BE01-17 | Caching, Rate Limiting & Performance — What Interviewers Look For

Caching, rate limiting, and performance questions are where *system design interviews separate theoretical knowledge from real-world engineering judgment* .

In *Video* , we focus on how backend systems stay *fast, stable, and protected under real traffic* — and what interviewers are *actually* evaluating when they ask performance-related questions.

This video goes beyond “just add Redis” or “optimize later” and shows how to *reason about trade-offs* , protect systems from abuse, and maintain latency SLAs at scale.

### What you’ll learn in this video:

* What *performance really means* in system design interviews
* Why interviewers care about caching, rate limiting, and protection
* When caching helps — and when it hurts
* Different caching layers:

* Server-side caching (Redis, Memcached)
* HTTP / client-side caching
* CDN caching
* Cache invalidation strategies and why it’s a critical interview topic
* Common caching mistakes that kill interview answers
* Why rate limiting exists and what problems it solves
* High-level rate limiting strategies (fixed window, token bucket, leaky bucket)
* Where to apply rate limits in real systems
* Database performance pitfalls (indexes, N+1 queries, unbounded reads)
* Application-level performance techniques:

* Asynchronous processing
* Connection pooling
* Profiling and measurement
* The difference between *premature* and *strategic* optimization
* A reusable *interview answer framework* for performance questions

### Who this video is for:

* Backend engineers
* Software engineers preparing for *system design interviews*
* FAANG / Big Tech interview candidates
* Developers who want to understand *performance beyond buzzwords*

This video is designed for *deep understanding and interview confidence* , not memorizing patterns.

If this helped you:

* Like the video
* Drop your interview questions in the comments
* Subscribe for the next video on *Fault Tolerance, Reliability & Failure Handling*

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This channel is about real-world software engineering — systems, backend, interviews, and intelligence explained.

Most tutorials teach tools.
Real engineering is about how systems work, scale, and fail in production.

In this video, I explain the topic from a systems-first perspective, connecting fundamentals, real-world usage, and how it appears in technical interviews.

This is not a course.
This is real engineering thinking.

If you're a developer, student, or interview candidate who wants to understand software deeply, consider subscribing.

Topics on this channel include backend engineering, system design, software engineering interviews, and engineering fundamentals.

— Danishan Farookh

#SoftwareEngineering #SystemDesign #BackendEngineering #TechInterviews

Видео BE01-17 | Caching, Rate Limiting & Performance — What Interviewers Look For канала danishan4u