Milind's notes taken from the Backend in Node.js from Scratch Course by Sanket Singh

Backend Engineering, Low-Level Design, System Design, Networking, Security, SQL, and Distributed Systems explained through visual diagrams.

Learn backend engineering through real production failure cases.

Production-grade cryptocurrency trading engine simulator with event-driven architecture, atomic balance updates, and thread-safe order matching. Built with Spring Boot 3.3+, Kafka, PostgreSQL, and Docker. Perfect for showcasing backend engineering skills!

A handbook for Backend Engineering

Autonomous infrastructure recovery engine featuring predictive anomaly detection and self-healing capabilities for critical backend systems.

Enterprise-grade Event-Driven Webhook Service built with NestJS. Architected for high-reliability processing of mission-critical data from Stripe, PayPal, and GitHub. Features include HMAC security, idempotency control, BullMQ-based asynchronous processing with DLQ patterns, and distributed tracing with OpenTelemetry.

Experimental Subset Sum solver for large integers using SQLite as an out-of-core storage engine.

High-Reliability Code Execution Engine - Monorepo with Standalone HTML IDE, Node.js/Fastify Backend on Render, E2E Tests & CI/CD.

A lightweight Java 17 HTTP micro-framework with explicit routing, middleware composition, and production-focused runtime controls.

A high-performance Zero-Trust security proxy designed for data privacy and compliance. Implements dynamic data masking (DDM), AES-256 encryption, and automated PII detection to secure sensitive data flows in enterprise environments. Engineered for HIPAA/GDPR alignment.

System Design in Bengali

Docs for BootArc. (under development)

A clean Java backend application for a Hotel Reservation System. Features include searching rooms by category (Standard, Deluxe, Suite), managing bookings, simulating a secure payment checkout, and handling cancellations. Built using core Object-Oriented Programming (OOP) principles for the CodeAlpha Java Programming Internship.

A platform to learn to build systems at scale, from backend to LLMs.

Production-grade shell automation, system administration, and infrastructure-as-code implementations. This serves as a practical, low-level foundation in Linux internals, networking architectures, and web stack optimization, bridging core system engineering with modern Backend and DevOps methodologies.

A Production-grade Rental Management System for handling properties, tenants, leases, rent payments, and maintenance workflows.

This is a case study on implementing StackOverflow main features as an REST API

Practice how senior engineers think. Failure modes, tradeoffs, production realities. Hands‑on exercises, rubrics, and AI‑assisted evaluation to close the gap to senior.

Production-oriented backend application written in Go. Demonstrates layered architecture, PostgreSQL, Redis Cache-Aside, middleware, context propagation, structured logging, and graceful shutdown.