Java · Spring Boot · Kafka · Kubernetes · AWS

Java full stack engineering, from both sides of the table.

I'm Shubham Chepe — a full stack Java developer (Spring Boot, microservices, React.js, AWS) and a Technical Support Engineer at Salesforce. I write about building Java systems that ship, and what I've learned about how they break in production.

Java 27 · JVM · Spring Boot

Java 27 is out: what actually changes for your Spring Boot services

G1 everywhere, compact object headers and post-quantum TLS — the JDK 27 changes that land automatically, and how to check your containers.
Java 25 · Project Leyden · Performance

Faster Spring Boot startup with the Java 25 AOT cache

Project Leyden's AOT cache in three commands and one Dockerfile — no code changes, no native build.
Java · JVM · Project Valhalla

Project Valhalla: why two equal numbers in Java can fail ==

Java's 30-year-old identity problem, explained plainly — and how JEP 401 value classes finally fix it.
Spring Boot 4 · Migration · Jackson 3

Spring Boot 3.5 is out of support: a practical Spring Boot 4 migration guide

The order to migrate in, the code changes for Jackson 3 and tests, and the silent traps — from Spring Batch metadata to Undertow.
Spring Boot 4 · REST API · API Design

API versioning is finally built into Spring Boot 4

Header, path or media type — configure versioning in properties, version endpoints with one attribute, and retire old versions without breaking clients.
Virtual Threads · Spring Boot · Java 25

Virtual threads in Spring Boot: one property, three things that still bite

Enable them in one line — then handle the connection-pool bottleneck, ThreadLocal caches and CPU-bound work that trip teams up.
Spring Boot · REST API · React

Spring Boot error handling done right: ProblemDetail and @RestControllerAdvice

Why bare 500s become support tickets — and how to return specific, consistent errors from Spring Boot that a React frontend can handle in one place.
Spring Data JPA · Hibernate · Performance

The query that runs 101 times: fixing N+1 in Spring Data JPA

The playbook behind a 40% API speed-up: how to spot N+1 queries, four ways to fix them, and the Hibernate traps that catch experienced developers.
Spring Boot · Microservices · Observability

Logs are written for a stranger at 2am: correlation IDs in Spring Boot

Trace one request across microservices in seconds: MDC, a request filter, structured JSON logs, and the async trap that silently loses your IDs.
Spring AI · MCP · Spring Boot 4

Build an MCP server in Java with Spring AI 2.0

Expose Spring Boot services to AI assistants with one annotation — plus the security, validation and observability that production MCP servers need.
Kafka 4.2 · KIP-932 · Messaging

Kafka can finally act like a queue: share groups for Java developers

KIP-932 explained: per-record acknowledgement, consumers beyond partition count, a KafkaShareConsumer example, and what's still missing.
Kubernetes · Spring Boot · DevOps

Spring Boot on Kubernetes: the production checklist

Probes that don't restart healthy pods, deployments that don't drop requests, and JVM memory settings that respect container limits.
Kubernetes 1.35 · JVM · Autoscaling

In-place pod resize and the JVM: CPU yes, memory careful

Kubernetes 1.35 can resize running pods — but a JVM sizes its heap once. The resize policy every Java team should set.
AWS Lambda · SnapStart · Java 25

Java on AWS Lambda in 2026: SnapStart vs native vs Managed Instances

Four ways to run Spring Boot on Lambda, compared with AWS's own Java 25 benchmark — plus CRaC priming code and a decision guide.
Career · Salesforce · Java

From full stack Java developer to Salesforce Technical Support Engineer

Why Salesforce hires developers into support engineering, and five lessons from the other side of the table that changed how I write Java.