System Design Components

Microservices

Great for large-scale systems requiring independent scalability, modularity, and resilience. Helps avoid monolithic pitfalls like tight coupling, redeployment issues, and shared failures.

Cons: Complex to manage; requires robust service communication and monitoring. Not ideal for small apps due to overhead and complexity.

Relational Database

Ideal for applications requiring structured data, strong consistency, complex queries, and ACID transactions. Common in finance, user systems, etc.

Cons: Struggles with horizontal scaling and unstructured data. Not ideal for high-volume write-heavy or schema-less workloads.

NoSQL Database

Best for unstructured or semi-structured data, high scalability, and flexible schemas. Ideal for content management, user-generated content, analytics.


Cons: Lacks ACID compliance and relational constraints. Not optimal for data that requires complex joins or strong consistency.

Object Storage

Great for storing unstructured data like images, videos, backups. Scalable, cost-effective, with strong durability. Common in media delivery, big data, ML.

Cons: Slower for low-latency operations. Not suitable for transactional or relational data needing frequent updates.

Cache

Ideal for high-read, low-write workloads to reduce latency and backend load. Used in social media feeds, product pages, or repeated queries.

Cons: Requires careful invalidation and eviction policies. Stale data risks; not ideal if frequent updates or consistency is critical.

CDN (Content Delivery Network)

Used to deliver static assets globally with low latency by caching data at edge locations. Great for images, JS, CSS, videos. Reduces origin server load and speeds up page loads.

Cons: Not useful for dynamic or sensitive data. Cache invalidation can be complex.

Message Queue

Ideal for decoupling services and managing background tasks or asynchronous workflows. Common in order processing, email notifications, log pipelines.

Cons: Added complexity, eventual consistency issues, message duplication, and ordering concerns.

API Gateway

Single entry point for routing, authentication, rate limiting, and aggregation in microservice architectures. Simplifies client interaction and security.

Cons: Can become a bottleneck or single point of failure. Adds operational complexity.