System Design

OAuth 2.0 / OIDC for Spring Boot microservices ...

1) Big picture [Browser / Mobile / SPA] | (Auth Code + PKCE) v +------------------------+ (JWT or opaque access tokens) | PingFederate (AS) | ---> [JWKS endpoint / Introspection] |...

Payment Gateway integration with Spring Boot

1) Goals & non‑negotiables High TPS & low latency: sub‑200ms for your own APIs (excluding external gateway hops). Exactly‑once effects: no double charges or double refunds. Idempotency everywhere: API, workers,...

Deploy Java application with Complete CI/CD pip...

Here’s a clean, end-to-end CI/CD example for a typical Java (Spring Boot) app using Jenkins → Docker → Helm → Kubernetes. You can swap the deploy step for EC2/Tomcat if...

How to find Memory Leakage & Fix them?

1) Spot the leak (symptoms) Process RSS/heap grows steadily and never comes down. More frequent/full GCs, rising old‑gen after each GC, GC pauses lengthen. OOMKilled (K8s) or OutOfMemoryError in logs....

Calculating TPS & Resource Estimations

1) Basic definition (the “count & divide” way) TPS = (number of completed transactions) ÷ (time window in seconds)Use a steady window (exclude warm-up/cool-down) and count successful transactions separately from...

How do you deploy microservices in production?

1) Foundations (before any deploy) Containers: one image per service, multi‑stage builds, SBOM + signature (Cosign). IaC: VPC, clusters, gateways, DBs via Terraform/Pulumi; everything versioned. Environments: dev → stage →...