Technical - System Design

Question 1

CDN / Cache Invalidation

Question 2

WAF

Question 3

Load Balancers (L7 vs L4)

Question 4

Session Affinity / Sticky Sessions

Question 5

Cache Architecture (w/examples)

Question 6

Queue Architecture (Kafka vs RabbitMQ)

Question 7

SOA vs EDA vs MSA

Question 8

Database commit strategies

Question 9

Database sharding

Question 10

NoSQL vs SQL

Question 11

Database partitioning

Question 12

API Gateway

Question 13

Kafka

Answer 13

• Producers: Write messages to 1…n topics
  
  • Partitioning strategy specific by producer, default partitions by key (messages of same key always in order)
• Consumer: Pull messages from 1…n topics based on consumer offset
• Topic > Partitions > Segment
• Partitions stored on 1 or more broker based on replication factor (lead > follower)

Question 14

API Best Practices

Answer 14

1. Idempotent
2. Versioned
3. Large response = paginated (offset, limit)
   - /offset=20&limit=10
4. Long response time = asynchronous

Question 15

Cache-Control HTTP Directives

Answer 15

Directives used in http headers to control caching behavior (ex: max-age, no-cache, public, private)

Question 16

Geo-routing and cross-region redundancy

Question 17

CAP Theorem

Question 18

ACID Compliance

Question 19

Index (Pros, Cons)

Question 20

Best practices for scaling databases

Answer 20

1. Indexes
2. Replication
3. Partitioning/Sharding

Question 21

EDA (Event sourcing, CQRS)

Question 22

Batch vs Rea Time vs Lambda

Question 23

Skeleton screens

Question 24

Lazy loading vs infinity scroll