Fine calculation in LLD - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Fine Calculation Components

Which of the following components is essential for designing a fine calculation system for a library?

A Weather API, book inventory, fine rules engine, payment gateway

B User database, book inventory, fine rules engine, payment gateway

C User database, book inventory, social media integration, payment gateway

D User database, book inventory, fine rules engine, video streaming service

💡 Hint

Think about what is needed to calculate fines and collect payments.

A fine calculation system needs to know who the user is, what books they have, the rules for fines, and a way to collect payments.

❓ Architecture

intermediate

Designing a Scalable Fine Calculation System

Which architecture best supports a fine calculation system that must handle millions of users with low latency?

A Microservices with separate services for user management, fine calculation, and payment processing

B Single server with in-memory cache for all data

C Monolithic application with a single database

D Peer-to-peer network without centralized control

💡 Hint

Consider scalability and separation of concerns.

Microservices allow independent scaling of components like fine calculation and payment processing, improving performance and maintainability.

❓ scaling

advanced

Handling Peak Load in Fine Calculation System

During peak hours, the fine calculation system experiences high traffic. Which approach best ensures system availability and responsiveness?

A Use a load balancer with auto-scaling groups for fine calculation services

B Increase the database size without changing the architecture

C Disable fine calculation temporarily during peak hours

D Use a single powerful server to handle all requests

💡 Hint

Think about distributing load and scaling dynamically.

Load balancers distribute requests evenly, and auto-scaling adds more service instances automatically to handle increased load.

❓ tradeoff

advanced

Choosing Between Real-Time and Batch Fine Calculation

What is the main tradeoff when choosing real-time fine calculation over batch processing?

A Real-time can only handle small data; batch can only handle large data

B Real-time is cheaper but less accurate; batch is expensive but always accurate

C Real-time requires no database; batch requires a database

D Real-time provides immediate feedback but requires more computing resources; batch is resource-efficient but delayed

💡 Hint

Consider speed versus resource usage.

Real-time calculation gives instant results but needs more CPU and memory; batch processing saves resources but results are delayed.

❓ estimation

expert

Estimating Storage for Fine Calculation Logs

A fine calculation system logs each fine event with 1 KB of data. If the system expects 10 million fine events per month, what is the approximate storage needed per year?

A 12 TB

B 120 TB

C 120 GB

D 1.2 TB

💡 Hint

Calculate monthly data and multiply by 12 months.

10 million events × 1 KB = 10 million KB = ~10 GB per month. For 12 months, 10 GB × 12 = 120 GB. But 10 million KB is actually about 10 GB, so 10 million KB × 12 = 120 GB. Check units carefully.