04Writing9 notes

Engineering notes

Practical notes on backend architecture, security, and modern full-stack patterns.

Jun 28, 2026 9 min

How I Use Claude, Codex, and Gemini to Ship Faster: My Agentic Development Workflow

Context engineering, spec-driven development, agentic testing with browser automation, and multi-agent orchestration — how AI tools changed how I build software.

AIClaude CodeAgentic TestingContext Engineering

Jun 25, 2026 9 min

Building 18 Microservices with Spring Cloud: What I Learned from Procraftor

Practical lessons from decomposing a marketplace platform into 18+ microservices with Spring Cloud, Eureka, API Gateway, and Resilience4j.

MicroservicesSpring CloudKubernetesArchitecture

Jun 10, 2026 8 min

Integrating AI Agents into SaaS Products: WhatsApp Bot + RAG Pipeline

How I built an AI-powered WhatsApp assistant with intent classification, agent orchestration, and a RAG pipeline for PharmacyHub.

AIWhatsApp BotRAGSpring Boot

May 28, 2026 7 min

Designing Multi-Tenant SaaS with Spring Boot and Keycloak

How I handle tenant isolation, authentication, and data separation in CRMCup and PharmacyHub using JHipster, Keycloak, and PostgreSQL.

SaaSMulti-tenantKeycloakSpring Boot

May 20, 2026 6 min

How I Structure a Spring Boot REST API for Production

A pragmatic layering, validation, and error-handling setup for production Spring Boot REST APIs.

JavaSpring BootREST APIArchitecture

Apr 22, 2026 7 min

Customizing an Enterprise POS Without Breaking the Base Product

Lessons from customizing a shared Vision POS platform for multiple international retailers.

JavaSpringPOS SystemsEnterprise

Mar 28, 2026 8 min

Aggregating JIRA Data with Spring Boot and Elasticsearch

How I built Khoji — a tool that consolidates JIRA data and raises progress alerts using Spring Boot, Elasticsearch, and Logstash.

Spring BootElasticsearchLogstashTooling

Feb 15, 2026 6 min

MyBatis vs JPA/Hibernate: When I Reach for Each

A practical comparison of MyBatis and JPA/Hibernate based on real enterprise and personal-project use.

JavaMyBatisHibernateJPA

Jan 18, 2026 7 min

Structuring a Spring Boot Business Management System

How I organize inventory, sales, billing, and reporting in a Spring Boot business system, from real pharmacy and patient projects.

Spring BootArchitectureBusiness System