Kafka

# Title Why Kafka (Problem) When to Use It How to Apply It What Kafka Concept Solves It Example Scenario
1 Explosion of Data Volume Need to handle billions of events at scale When your system ingests continuous, massive streams Scale horizontally with partitions Topics + Partitions LinkedIn handling profile views, job clicks, ad impressions
2 Multiple Consumers, One Data Source Multiple teams need the same data When analytics, fraud detection, and reporting all need identical streams Use independent consumer groups Consumer Groups Payment service β†’ Fraud team + Analytics + Data Warehouse
3 Replay for Debugging & ML Debugging & ML need data replay When you need to reprocess past data Enable log retention & control offsets Offsets + Retention Replaying 1 year of user clicks to re-train an ML model
4 One Pipeline for Real-time + Batch Must support both real-time + batch When you want one pipeline for dashboards + ETL Mix stream consumers & batch consumers (via Connect) Kafka Connect + Stream APIs E-commerce system: live inventory + nightly sales reports
5 Fault Tolerance by Design Prevent data loss on failures When uptime and durability are mission-critical Replicate partitions across brokers Replication + Leader/Follower Bank processing transactions with 0 tolerance for loss
6 Decoupling Producers & Consumers Avoid producer-consumer coupling When new consumers must join without disturbing producers Producers write once, consumers subscribe freely Decoupled Pub/Sub IoT sensor data β†’ analytics, monitoring, ML pipelines
7 Guaranteed Event Ordering Need event ordering When events per user/session must stay in order Key-based partitioning Partition + Ordering Guarantee Chat app β†’ messages for same user land in order
8 Stream Processing in Motion Process streams in motion When you must enrich/filter/aggregate data on the fly Use Kafka Streams or KSQL Stream Processing Ride-sharing: calculate ETA with live traffic data
9 Plug-and-Play Integrations Integrate with existing systems When data must flow to DBs, cloud storage, or other clusters Use Kafka Connect connectors Connectors Push logs to Elastic, load sales into Snowflake
10 Global Data Distribution Build geo-distributed systems When you need multi-DC/cloud active-active setups Replicate topics across clusters MirrorMaker / Cluster Linking Global SaaS syncing events across regions