Interactive Learning Tools

Hands-on simulators to explore distributed systems and cloud concepts. Pick a topic and start experimenting.

📨

Kafka Playground

Visualize producers, partitions, consumer groups, and message flow in an interactive Kafka cluster simulation.

Kafka Streaming Partitions Consumer Groups
🚦

Rate Limit Simulator

Experiment with AWS API Gateway rate limiting — token buckets, throttling, and burst behavior in real time.

AWS API Gateway Rate Limiting Token Bucket
🧠

Redis Cluster Explainer

Visualize sharding, replication, and failover. Hash slots, MOVED/ASK redirects, gossip-based promotion, and dynamicRefreshSources.

Redis Sharding Replication Failover
🔍

Lettuce DNS Resolution

JVM vs Netty DNS resolver — blocking vs async, TTL caching, EKS CoreDNS flow, and the FQDN/ndots query explosion. All interactive.

Lettuce DNS EKS CoreDNS

Quartz Cluster on Spring Boot

How multiple pods coordinate to run a scheduled job exactly once. Lock race, all 11 QRTZ tables, misfire policies, failover, and Actuator health checks.

Quartz Spring Boot Cron Cluster
🔐

IRSA on EKS

Build the ServiceAccount + IAM trust policy, watch the AssumeRoleWithWebIdentity token exchange flow, inspect JWT claims, and diagnose real-world IRSA pitfalls.

EKS IAM OIDC JWT
🌱

Spring MVC vs WebFlux

Side-by-side load test. Watch the thread-per-request model saturate while the reactive event loop keeps up — and see what happens when you accidentally block.

Spring Reactive Threading Backpressure
🔑

OAuth 2.0 + PKCE

Walk through the Authorization Code flow without PKCE, watch the interception attack steal a token, then see PKCE shut it down. JWT inspector and OIDC included.

OAuth 2.0 PKCE OIDC JWT