Reverse proxy concept in HLD - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Role of a Reverse Proxy in Web Architecture

Which of the following best describes the primary role of a reverse proxy in a web system?

A It directly serves static files without contacting backend servers.

B It forwards client requests to backend servers and can provide load balancing and caching.

C It acts as a client to fetch data from the internet on behalf of the server.

D It stores user credentials and manages authentication tokens.

💡 Hint

Think about what a reverse proxy does between clients and servers.

A reverse proxy sits in front of backend servers, forwarding client requests to them. It can also balance load, cache responses, and improve security.

❓ Architecture

intermediate

Reverse Proxy Placement in System Architecture

Where is a reverse proxy typically placed in a web application architecture?

A Directly inside the backend database to optimize queries.

B Between the backend servers and the database to manage data flow.

C On the client device to cache server responses locally.

D Between the client and the backend servers, acting as an intermediary.

💡 Hint

Consider the flow of requests from users to servers.

A reverse proxy is placed between clients and backend servers to intercept and manage incoming requests.

❓ scaling

advanced

Scaling Backend Servers with Reverse Proxy

How does a reverse proxy help scale backend servers in a high-traffic web application?

A By distributing incoming requests evenly across multiple backend servers to prevent overload.

B By storing all user sessions locally to reduce backend load.

C By encrypting all data between backend servers and clients to improve security.

D By replacing backend servers with a single powerful server to handle all requests.

💡 Hint

Think about how load balancing works in web systems.

A reverse proxy can distribute client requests across multiple backend servers, balancing load and improving scalability.

❓ tradeoff

advanced

Tradeoffs of Using a Reverse Proxy

Which is a common tradeoff when introducing a reverse proxy into a system?

A Directly exposes backend servers to the internet, increasing risk.

B Eliminates the need for backend servers, reducing complexity.

C Adds an extra network hop which can increase latency but improves security and scalability.

D Removes all caching capabilities from the system, reducing performance.

💡 Hint

Consider both benefits and costs of adding components in a network path.

While a reverse proxy adds an extra step in request handling, it improves security, caching, and load balancing, which outweighs the slight latency increase.

❓ estimation

expert

Estimating Reverse Proxy Capacity for Traffic Load

A reverse proxy handles 10,000 requests per second. Each request averages 500KB response size. What is the approximate outgoing bandwidth needed for the reverse proxy?

A About 50 Gbps

B About 5 Gbps

C About 500 Mbps

D About 50 Mbps

💡 Hint

Calculate bandwidth = requests per second × response size in bits.

10,000 requests/s × 500KB = 5,000,000 KB/s = 5 GB/s. Convert to bits: 5 GB/s × 8 = 40 Gbps. But 500KB is 0.5MB, so 10,000 × 0.5MB = 5,000 MB/s = 5 GB/s. Actually, 5 GB/s × 8 = 40 Gbps. The correct option closest is 5 Gbps, so re-check units: 500KB = 500 × 1024 bytes = 512,000 bytes = 4,096,000 bits. 10,000 × 4,096,000 bits = 40,960,000,000 bits/s = 40.96 Gbps. So correct is about 40 Gbps, closest option is 50 Gbps (D). So correct answer is D.