2024 System Design Interview Categories Summary

Having gone through multiple interviews myself and also having interviewed many candidates, I’ve learned from experience that for beginner system designers, the most crucial skill is the ability to identify the type of system design question being asked. Recognizing the type and understanding the key challenges associated with it is half the battle. Otherwise, it’s easy to go off-track, leaving both yourself and the interviewer confused.

System design questions generally fall into four main categories, each with its own specific focus and best practices. In many ways, these problems follow established patterns.

1. Read-Heavy Systems
   These systems handle a high volume of read requests. A common example domain would be social media platforms. For instance, a question like “Design Instagram” would fall into this category. The solution would typically involve techniques like caching, CDN (Content Delivery Network), and database sharding.

2. Write-Heavy Systems
   Write-heavy systems are those where the ratio of write operations is significant compared to read operations (usually when the read-to-write ratio is below 1:1). An example domain could be a voting system. A typical question here might be to “Design a Rate Limiter.” Solutions often involve batch data processing and message queues to handle the load.

3. Scheduler Systems
   These systems deal with tasks that require high concurrency and distributed deployment. An example of a question in this category could be designing a web crawler. Key components of the solution would include message queues and mechanisms for failure retries to ensure tasks are completed reliably across distributed systems.

4. Consistency-Heavy Systems
   These are systems where data consistency is critical, often found in domains like payment systems or e-commerce platforms. For example, a question like “Design Amazon’s Inventory System” would fit here. Solutions would likely include components like MySQL database locks and mechanisms for handling retries to ensure data consistency.

If your solution doesn’t include these essential components based on the question category, there’s a good chance that you’re missing something crucial.

For more detailed explanations and solutions, I’ve posted additional resources on bugfree.ai for further reference!