ملاحظات هندسية وعمل مفتوح المصدر

توثيق رحلتي الهندسية ومساهماتي.

Blog Articles

Using RAG for SQL Generation — Why Embeddings Beat Prompt Stuffing

8 min read

Jan 28, 2026

How pgvector embeddings improve LLM-to-SQL accuracy by providing schema context instead of dumping entire schemas into prompts.

rag sql generationpgvector embeddings sqltext to sql pgvector

Building an MCP Server with Spring Boot — A Practical Guide

10 min read

Jan 20, 2026

Implementing the Model Context Protocol for AI assistant tool integration using Spring Boot and Spring AI.

mcp server spring bootmodel context protocol tutorialspring ai mcp

Offline-First PWA Patterns — Service Workers, IndexedDB, and Background Sync

7 min read

Jan 15, 2026

Service workers, IndexedDB, and background sync patterns used in MicroItinerary for reliable offline-first travel planning.

pwa offline sync indexeddbservice worker background syncoffline first web app

خلاصة المساهمات

rohitraj.tech Redesign

open source

backendscale·2026-01-31

Complete redesign from consultancy landing page to engineer-centric project directory with documentation-first aesthetic.

Live at rohitraj.tech

src/appsrc/componentssrc/data
GitHub →

MicroItinerary — AI Travel Planner

ai systems

MicroItinerary·2026-01-27

AI-powered PWA for planning annual travel itineraries. Features intelligent destination suggestions via OpenAI GPT-4, cost estimation in INR, and Splitwise-style expense splitting for group trips.

Full-stack PWA with offline support, Google OAuth, Redis caching

backendwebdocker-compose.yml
GitHub →

StellarMIND — Chat-to-SQL with pgvector

ai systems

spring-ai-mcp-server·2026-01-25

Spring Boot MCP server that converts natural language questions into read-only SQL using LLM. Retrieves schema context via pgvector for RAG-based query generation.

Natural language → SQL with safe read-only execution

stellarmind-serverstellarmind-client
GitHub →

AWS SQS Integration Patterns

open source

sqs·2021-12-27

Reference implementation for AWS SQS integration with Spring Boot including producer/consumer patterns, retry logic, and dead-letter queue handling.

producerconsumer
GitHub →

ملخص المستودع

backendscale
TypeScriptactive

Engineering work visibility — portfolios show results but not thinking

Full implementation: Next.js 16, React 19, documentation-first design system

src/appsrc/componentssrc/data
MicroItinerary
Javaactive

Travel apps lack intelligent suggestions and group expense management

Full-stack: Spring Boot 3.2.2 + Java 21 backend, React 18 + Vite PWA, OpenAI integration

backendwebtest
spring-ai-mcp-server
Javaactive

Natural language database queries with retrieval-augmented context via pgvector

Full MCP server implementation, pgvector integration, Chain-of-Thought UI

stellarmind-serverstellarmind-clientpostman
my-expense
Javamaintenance

Simple expense tracking without bloated features

Full-stack Java application with REST API

apipersistencereports
sqs
Javaarchived

Reference implementation for AWS SQS with Spring Boot

Producer/consumer patterns, retry logic, DLQ handling

producerconsumerconfig
wealwa-api
Javaarchived

Personal wealth tracking and portfolio management

REST API design, portfolio analytics

apiportfolioanalytics

عرض جميع المستودعات

ملاحظات المشروع

backendscale (rohitraj.tech)

frontend

لماذا يوجد

Engineering work is often invisible. Traditional portfolios show polished results but not the thinking process.

التحدي الأساسي

Creating a documentation-first design system that feels like internal engineering docs while remaining visually professional.

الهندسة المعمارية

  • Next.js 16 with App Router for static generation where possible
  • React 19 with server components for optimal performance
  • Tailwind v4 for utility-first styling
  • Data-driven content structure in src/data/ for easy updates

المقايضات

  • Chose vanilla CSS over component libraries for full control, at cost of development speed
  • Static generation means content updates require redeployment
  • Minimal dependencies reduce maintenance burden but limit feature velocity
Production — deployed on VercelView Repository →

MicroItinerary

ai systems

لماذا يوجد

Travel apps lack intelligent suggestions based on season/budget and don't handle group expense splitting well.

التحدي الأساسي

Integrating OpenAI GPT-4 for destination suggestions and cost estimation while maintaining offline-first PWA capabilities.

الهندسة المعمارية

  • React 18 + Vite PWA frontend with IndexedDB for offline support
  • Spring Boot 3.2.2 + Java 21 backend with Flyway migrations
  • PostgreSQL 16 + Redis caching layer
  • Google OAuth 2.0 + JWT authentication
  • OpenAI GPT-4 API for AI features

المقايضات

  • PWA over native app — broader reach but limited device APIs
  • OpenAI API adds latency and cost vs simpler rule-based suggestions
  • Expense splitting algorithm prioritizes simplicity over Splitwise feature-parity
Development — backend and frontend functional, needs polishView Repository →

StellarMIND (spring-ai-mcp-server)

ai systems

لماذا يوجد

Business users need to query databases without knowing SQL. Existing tools lack context-aware query generation.

التحدي الأساسي

Retrieval-augmented SQL generation using pgvector for schema context, with strict read-only query enforcement for safety.

الهندسة المعمارية

  • Spring Boot MCP server with Tool interface for query execution
  • pgvector for storing schema knowledge chunks and embeddings
  • Spring AI for LLM integration (provider-agnostic)
  • Chain-of-Thought (CoT) web interface for query debugging
  • Read-only SQL enforcement (only SELECT, WITH allowed)

المقايضات

  • Read-only restriction limits use cases but ensures safety
  • pgvector requires PostgreSQL — not database-agnostic
  • MCP transport (stdio) limits deployment patterns vs HTTP
Development — core query flow working, needs UI polishView Repository →