01 — WHOAMI

Prahlad
Singh.

Full-Stack Developer · MERN / MEVN · Building at scale

prahlad@dev — bash

prahlad@dev:~$ cat about.md

// WHO I AM

Full-stack developer based in Gurgaon, specializing in the MERN/MEVN stack. I work across the entire lifecycle of a product — designing MongoDB schemas and multi-tenant architecture on one end, and shipping pixel-perfect, responsive React/Vue interfaces on the other. I care about writing code that's secure, maintainable, and actually holds up in production, not just in a demo.

// WHAT I DO

I design and build RESTful APIs, multi-tenant SaaS architectures with per-tenant data isolation, and JWT/RBAC authentication systems with fine-grained role control. On the real-time side, I've built video calling, live GPS tracking, and instant notifications with Socket.io, PeerJS, and Redis. I also build cross-platform mobile apps with React Native (Expo), terminal/CLI tools with Node.js, data-visualization dashboards with Chart.js and Three.js, work on niche builds like a DICOM medical imaging viewer, Razorpay payment integrations, and PDF generation pipelines — and I handle my own DevOps: Linux VPS setup, Nginx, PM2, and CI/CD with GitHub Actions.

Years XP

Projects Shipped

Technologies

∞

Coffee ☕

02 — ARSENAL

Tech
Stack.

Tools I reach for — and the ones I've earned

⬡

Frontend

Vue.jsReact.js React NativeNext.js JavaScriptHTML5 CSS3Tailwind VuexVite

Vue.js90%

React.js78%

React Native72%

Next.js70%

JavaScript85%

◎

Backend

Node.jsExpress.js NestJSPHP Socket.io PeerJSRedis JWTRazorpay

Node.js88%

Express.js88%

NestJS70%

Socket.io80%

▣

Database

MongoDBMySQL MongooseMulti-tenant AggregationIndexing

MongoDB87%

MySQL72%

⚙

DevOps, Tools & APIs

LinuxNginx PM2GitHub Actions GitSSH/SCP SSLCloudinary PostmanPuppeteer OpenWeatherMapremove.bg npm PublishingCLI (Ink) Chart.jsThree.js Gemini APIGitHub API D3.jsTypeScript

03 — EXPERIENCE

Where I've
Shipped.

Production code. Real users. Actual problems solved.

CURRENT ROLE

Lifelayer Health Solutions Pvt. Ltd.

Backend Developer → Full-Stack

📅 Mar 2025 – Present 📍 Gurugram, India

Built a large-scale multi-tenant healthcare platform (MEVN) with per-company MongoDB database isolation, connection manager, and model factory pattern.
Developed a DICOM medical imaging viewer in Vue.js with multi-panel grid support (1×1 to 2×4), per-panel DWV instances, and drag-and-drop series loading.
Built production-grade telemedicine video system using PeerJS, Socket.io, and Redis session persistence.
Implemented ambulance booking and live GPS tracking with real-time Socket.io + Google Maps integration.
Integrated Razorpay payment gateway with Transaction schema, Puppeteer PDF invoicing, and webhook handling.
Designed JWT authentication with RBAC across 5+ roles; HIPAA-aligned MongoDB schemas with indexing.
Managed VPS deployments: Linux, Nginx reverse proxy, PM2 process management, CI/CD via GitHub Actions.

04 — PROJECTS

Things I
Built.

Full-stack MERN/MEVN systems — architected, built, and shipped end to end

Wardrobe Manager

Mobile Wardrobe & Outfit Planning App · React Native (Expo) + MERN

A full-stack mobile app for organizing your closet, building outfits, and getting weather-aware suggestions — built with React Native (Expo) on the front end and a Node.js/Express/MongoDB backend. Combines everyday wardrobe management with data-driven insights into what you actually wear.

Wardrobe grid with search, category filters, and infinite-scroll pagination
Reusable, fully editable outfit builder combining items into complete outfits
Laundry tracker that auto-excludes dirty items from suggestions & packing lists
"Today" tab — live weather-aware outfit suggestions (OpenWeatherMap + device location)
Trip packing-list generator pulling weather-appropriate items from the user's real closet, with the latest list persisted per user
Stats tab powered by MongoDB aggregation pipelines — wear timelines, most-worn & cost-per-wear leaderboards, closet value, category breakdowns — rendered with real charts via react-native-svg
Optional automatic background removal on item photos (remove.bg) and an in-app Server Settings screen for on-device backend URL configuration with a live connection test

React NativeExpo Node.jsExpress MongoDBreact-native-svg OpenWeatherMap APIremove.bg

DOWNLOAD APK GITHUB

ShareVault

Secure File & Video Sharing Platform · MERN

A production-ready file sharing platform with auto-expiring links, role-based access, and a dedicated admin Video Vault. Built the full system — from JWT auth and rate-limited uploads to a cron-based cleanup engine that purges expired files off the VPS filesystem every 10 minutes.

Password-protected, expiring public share links with OTP verification & download limits
Admin Video Vault — upload, stream, and manage videos separately from regular files
JWT access + refresh token auth (httpOnly cookies), bcrypt hashing, RBAC (user/admin)
Auto-expiry engine — 24hr TTL on user files, storage usage tracking, cleanup logs
Admin dashboard — analytics, storage stats, user management, unified file+video listings
Hardened uploads — Multer MIME/extension validation, path-traversal prevention, rate limiting

React 18Node.js ExpressMongoDB Tailwind CSSJWT React QueryNode Cron

LIVE DEMO GITHUB

MythLok

World Folklore & Mythology Platform · MERN

A community platform for discovering and contributing world folklore — ghost stories, mythological creatures, and regional legends from 20+ countries. Led the full architecture, including a large-scale refactor migrating the entire app from Indian state-wise to country-wise organization across frontend and backend.

500+ stories across 20+ countries with an interactive country-tile world map
Contributor workflow — multi-step submission, draft saving, admin review (approve/reject/request changes)
Bookmarks, 1–5 star ratings, comments, reading history, and a 10-badge achievement system
Admin CMS — analytics dashboard, user role/block management, broadcast notifications, featured story control
JWT auth with 4 roles, Redux Toolkit state, Cloudinary image uploads

React 18Redux Toolkit Node.jsExpress MongoDB CloudinaryJWT

LIVE DEMO GITHUB

School ERP

Multi-Tenant School Management System · MERN

A full multi-tenant ERP for schools covering academics, attendance, fees, and communication — built with a shared-database, tenant-scoped data model so a single deployment can serve many schools securely and independently.

Multi-tenant architecture — global vs. tenant-scoped Mongoose models, per-school data isolation
Student, teacher, class, timetable, exam, and homework management modules
Attendance tracking with role-based views for students, teachers, and parents
Fees & accounting module with scholarship handling and report generation
Notice board, leave requests, and real-time notifications via Socket.io
Redux-driven React frontend with role-based dashboards (super admin / school admin / teacher / student / parent)

ReactRedux Node.jsExpress MongoDBSocket.io Multi-Tenant

LIVE DEMO GITHUB

Zip Router

Single-Line Grid Puzzle Game · MERN

A full MERN-stack puzzle game where players trace a single continuous line through every cell of a grid, hitting numbered checkpoints in order without crossing blocked edges — with accounts, level progression, and star ratings. Built a procedural puzzle generator that guarantees a solvable, unique board for every level.

Procedural puzzle generator — randomized, Warnsdorff-ordered DFS producing a Hamiltonian path through every grid cell, with checkpoints and walls placed along the route
Levels generated once via a seed script and stored in MongoDB, so every player sees an identical board per level
Server-side path validation — client submits its full drawn path; server independently re-verifies grid coverage, adjacency, wall compliance, and checkpoint order before awarding completion, closing the "fake a fast time" exploit
Star-rating system based on completion-time thresholds, with per-user level locking and progression
JWT authentication via httpOnly cookies
Vite + React + Tailwind CSS frontend

React.jsNode.js Express.jsMongoDB MongooseJWT ViteTailwind CSS Algorithm Design

LIVE DEMO GITHUB

GrabVid

Terminal Video Downloader CLI · Node.js + Ink (React for CLI)

A terminal app for downloading videos from YouTube, X, Instagram, and more — built with Ink (React for CLI interfaces) instead of a typical scripting approach, giving it a real interactive UI inside the terminal. Published to npm as a globally installable CLI tool.

Interactive, keyboard-navigable format picker with live download progress, powered by yt-dlp
6 switchable color themes with a pixel-block wordmark; frame pulses while fetching/downloading
Persistent URL history — arrow-key recall, deduped, last 20 saved to a local config file
Quick flags (--best, --mp3) for one-shot downloads without the interactive picker
State machine across input → fetching → picking → downloading → done/error
Fixed cross-terminal rendering bugs to keep the frame layout consistent across different terminal emulators

Node.jsReact Inkyt-dlp CLInpm Package

NPM PACKAGE GITHUB

GitHub Personality Analyzer

AI-Powered Developer Profile Report · MERN + Gemini API

A full-stack web app that takes any GitHub username and generates a "developer personality" report — profile stats, personality badges, language breakdown, a commit heatmap, top repos, and an AI-written summary powered by Google's Gemini API. Includes a side-by-side compare mode for two developers.

6-axis personality radar chart — open-source score, docs quality, night-owl/early-bird activity, weekend activity, bug-hunting
Commit heatmap with streak badges, plus Commit Rhythm charts (hour-of-day / day-of-week) from GitHub's push-event data
Per-repo personality tags ("Well documented," "Actively maintained," "Stale") computed client-side
AI-written personality summary via the Gemini API, with a side-by-side compare mode for two developers
Light/dark theme toggle, an animated three.js constellation background with mouse parallax, export-as-image, and "Copy as Markdown"
Backend caching (node-cache, 15-min TTL) to stay within GitHub's API rate limits

ReactNode.js ExpressGitHub API Gemini APIChart.js Three.jsTailwind CSS

LIVE DEMO GITHUB

BrainVault

AI-Powered Knowledge Management & Graph · MERN + TypeScript + Gemini API

An AI-powered knowledge management system — save any URL from across the web and let AI extract, summarize, tag, and connect it into an interactive, Obsidian-style knowledge graph. Built the full save-URL pipeline, an auto-computed relationship engine, and a force-directed graph UI on top of a JWT-only auth system.

Save-URL pipeline — scrapes title, description, thumbnail, favicon, and reading time via Cheerio
Gemini API summarization, tagging, categorization & difficulty detection, with a silent local-heuristic fallback so saving never breaks if the AI provider fails
Relationship engine — auto-computed graph edges from shared tags, tech, domain & keyword overlap ("AI similarity"), plus manual links, each scored with a relationship strength
Interactive force-directed graph (d3-force) — pan, zoom, node drag, hover-to-highlight, category color-coding
Nested Collections, Read Later with reminder presets, favorites/pin/archive/trash with restore, tag autocomplete
Structured + natural-language search ("Show me React authentication articles"), export to JSON/CSV/Markdown, and Netscape-format bookmark import from Chrome/Firefox/Edge
Command palette (⌘K) for paste-to-save from anywhere, an analytics dashboard, standalone broken-link checker script, and a PWA shell

ReactTypeScript ViteNode.js ExpressMongoDB D3.jsGemini API Tailwind CSSJWT

LIVE DEMO GITHUB

InterviewVault

Interview-Prep Vault with Spaced Repetition & AI Coaching · MERN + Monaco + Gemini API

A dark-themed, glassmorphism interview-prep vault — track coding questions, write solutions in multiple languages with a real in-browser code runner, run a spaced-repetition revision schedule, and visualize progress on a GitHub-style activity heatmap. Built the full auth system, aggregation-driven dashboard, and five Gemini-powered AI coaching features end to end.

JWT auth — access token in memory + rotating refresh token in an httpOnly cookie, with an active-sessions panel (per-device browser/OS/IP, revoke one or all others)
Question Library with card & table views, infinite scroll, live filters, text search, and full CRUD
Spaced-repetition engine (1/3/7/15/30/60/90-day intervals) driving dashboard streaks, revision-due counts, and an activity heatmap
Question Detail page with a Monaco code editor (7 languages) and real "Run code" execution via the Piston sandboxed-execution API — stdout/stderr/compile errors/exit code
Collections with drag-and-drop reordering, standalone Companies/Topics pages, and a React Flow Graph View of Question ↔ Topic ↔ Company relationships
Export to JSON/Markdown/PDF (with JSON re-import), global search + command palette (⌘K), and an analytics page over the aggregation endpoints
Five Gemini-powered AI features — code explanation, similar/follow-up question suggestions, a guided mock-interviewer chat, AI-generated quizzes, and notes summarization

ReactNode.js ExpressMongoDB Monaco EditorReact Flow Piston APIGemini API JWTTailwind CSS

LIVE DEMO GITHUB

Clipboard Cloud

Real-Time Cross-Device Clipboard Sync · Next.js + NestJS + Socket.IO

Instant clipboard sync between devices — pair with a QR code or 6-digit code and anything copied on one device appears on the other in real time, no login required, with an optional account for permanently saved snippets. Built the full pairing/session system, the Socket.IO sync engine, and client-side end-to-end encryption.

Real-time sync of text, links, images & arbitrary files via Socket.IO, with drag-and-drop upload and OS-clipboard paste (Ctrl/Cmd+V)
QR-code or 6-digit code device pairing — any device to any device, no login required
Optional end-to-end encryption per session — AES-256-GCM key generated client-side (Web Crypto API) and never sent to the server, exchanged via QR URL fragment
Offline queue — pushes made while disconnected are queued in localStorage and auto-sent on reconnect
Clipboard history (last 20 items) with pin & search, Redis TTL-based auto-expiry, and a device list to view/remove paired devices
Optional JWT + MongoDB accounts for permanently saved snippets, plus hardening — rate limiting, Helmet headers, per-session file ownership checks, blocked executable extensions