YUDEE.DEVOPENING EYE

Uday Singh

FULL-STACK SOFTWARE ENGINEER

// FRONTEND ENGINEER · REACT / NEXT.JS

Uday
Singh_

I build fast, multilingual Next.js and React apps — marketplaces, SaaS dashboards and streaming AI chat. And I squash bugs. Try it →

BASED: Durgapur, IN
NOW: KajKarma, remote
SHIPPING: Next.js · i18n · SEO

DEBUG.EXE— IDLESQUASHED 00TIME 00:30BEST 00

✗ bugs in prod · a tiny game · 30s

00 / ABOUT

A developer from West Bengal who likes the whole stack — schema to pixel to deploy. I care about fast pages, clean data boundaries and interfaces that feel quiet.

Off the clock: books, ukulele, too many movies.

01 / WORK

$ cat experience.log

KajKarma — Full-Stack Software Engineer

APR 2025 → PRESENT · REMOTE

Built and shipped production web and mobile apps end to end for international clients — enterprise ERP, B2B/B2C e-commerce, cross-platform mobile.
Full-stack from scratch with React, Next.js, React Native, Node.js, Express, MongoDB and TypeScript.
Owned AWS deployment with CI/CD — infrastructure, environment config and release workflows.
Strong PageSpeed scores across every project through SSR, code splitting and asset optimization.

DSMS College — BCA, CGPA 8.9

2022 → 2025 · DURGAPUR

02 / PROJECTS

4 featured · 17 more in the index

RESUME · FRONTEND ENGINEER · REACT / NEXT.JS

B2B / B2C · AI · 2025–2601

Uniglo Diamonds — web platform

177 App Router pages across 6 locales; generateMetadata on 142 pages with hreflang, JSON-LD and a sharded live-inventory sitemap, plus a streaming AI chat widget with interactive blocks.

✦ AI SALES ASSISTANT — holds stones, fills carts via 10 tools

177 pages · 6 locales · 1,000+ tests

NEXT.JS 16 · REACT 19 · OPENAI · EXPRESS · MONGODBvisit

SAAS · 202602

InstaPath — multi-tenant legal CRM

63 pages of server components with client islands and a TanStack Query layer (35 hooks, optimistic updates). Drag-and-drop Kanban, a FullCalendar scheduler, a no-code form builder and React-PDF invoices.

63 pages · 174 handlers · 68 test suites

NEXT.JS 15 · MONGODB · AUTH.JS · ZOD · DOCKERvisit

E-COMMERCE · 202603

Uniglo Jewels — build-your-own ring

BFF storefront with 42 localized pages, 41 server actions and JWTs in httpOnly cookies, plus an accessible search-by-photo flow with a keyboard-movable crop frame.

✦ SEARCH BY PHOTO — Bedrock embeddings + pgvector

3-step ring builder · Medusa · MapLibre

NEXT.JS 16 · MEDUSA V2 · PGVECTOR · STRIPEvisit

E-COMMERCE · 202604

I Want Jewels — a storefront in six languages

A Tiptap multilingual blog CMS, URL-synced shareable inventory filters, a 6-locale next-intl migration with 138 Vitest cases, and blog images cut from 99 MB to 52 MB.

6 locales · Stripe · JWT + OTP · admin panel

NEXT.JS · EXPRESS · MONGODB · STRIPE · AWSvisit

$ ls -la ~/projects --more

ROLE · SOLE DEVELOPER

An Expo app and a React dashboard on one Supabase backend: row-level security on all 5 tables, trigger-maintained balances, auth.uid()-checked RPCs and a pg_cron daily accrual job.

Expo + ReactSupabase RPCsPostgres (RLS, pg_cron)

EXPO · REACT · SUPABASE POSTGRES · RLS

↗

Jewellery store with per-field LLM product translation (JSON-validated, source-hash skipping, idempotent backfill with cost dry-runs) and multi-currency Stripe checkout.

NEXT.JS 16 · EXPRESS · MONGODB · STRIPE · OPENAI

↗

ROLE · CO-BUILT

Co-built a React SPA with 53 routes (42 lazy-loaded), permission-aware routing and a cheque-printing editor, over a one-database-per-tenant backend.

REACT 19 · VITE 7 · REACT ROUTER 7 · SHADCN/UI

↗

Multilingual FMCG store on Next.js 16 and next-intl with an Express, MongoDB and Stripe backend, migrated onto the client's own AWS.

NEXT.JS 16 · NEXT-INTL · EXPRESS · MONGODB · STRIPE

↗

B2B platform for a certified diamond supplier: server-rendered inventory filtered by cut, clarity, colour and carat, with IGI, GIA and HRD certificates.

NEXT.JS · REACT · TYPESCRIPT · TAILWIND

↗

Storefront for an Antwerp gemstone dealer: catalog browsing, accounts and lab-certification showcases.

NEXT.JS · REACT · TYPESCRIPT · TAILWIND

↗

B2B diamond supplier site with a gallery of 10+ cuts, certification showcases and a consultation booking flow.

NEXT.JS · TYPESCRIPT · TAILWIND

↗

Landing site for an Australian tax firm with interactive tax calculators and appointment scheduling.

NEXT.JS · TYPESCRIPT · FRAMER MOTION

ROLE · SOLO, IN TWO DAYS

Rebuilt a listing page from screenshots in two days, with a booking calendar and URL-addressable, accessible overlays.

NEXT.JS 16 · TAILWIND 4

↗

ROLE · BUILT THE OAUTH, CRAWL SERVICE AND AWS

Crawls a prospect's site, runs SEO, PageSpeed and competitor checks and has an LLM write the audit. Gmail and Zoho OAuth with encrypted tokens pull leads from inboxes; a Python crawl service feeds PostgreSQL exactly once.

Scrapy workersHMAC batchespg-boss APIPostgres

94 routes · 127 pytest tests · 16 CloudWatch alarmsEXPRESS 5 · PRISMA · POSTGRES · FASTAPI + SCRAPY · AWS

ROLE · LED THE PIPELINE

A 7-stage ETL pipeline (~8k lines) that fingerprints channels with GPT-4o, discovers creators through the YouTube API and ranks them with weighted embedding scoring, under a quota-aware Celery scheduler.

GPT-4o fingerprintYouTube searchembeddingsranked tiers

7 stages · 4 Celery lanes · idempotent upsertsFASTAPI · CELERY · REDIS · PANDAS · SCIKIT-LEARN · OPENAI

ROLE · DELIVERED THE SERVICE

A 17-endpoint service (~10.6k lines) that classifies documents, detects tables of contents and tables, and extracts clean text, then runs token-aware map-reduce LLM summarisation within a 30k tokens-per-minute limit.

PDFclassifyTOC + tablesmap-reduce summaryS3

17 endpoints · ~10.6k lines · 30k TPM budgetFASTAPI · CELERY · PYMUPDF · OPENAI · S3

A live market dashboard on the Upstox v3 WebSocket feed (protobuf) covering Nifty indices, option chain and Greeks, with auto-reconnect, a post-market 52-week job, price alerts and an LLM sector-risk score; plus a Python scraper for NSE lending data.

Upstox WebSocketprotobuf decodeSupabaseNext.js

NODE.JS · PROTOBUF · SUPABASE · NEXT.JS · PYTHON

A FastAPI service (9 endpoints) for parallel batch downloads with Redis job state and async ffmpeg streaming, deployed to AWS ECS through a 27-resource CloudFormation stack and GitHub Actions.

FastAPIRedis jobsasync ffmpegECS

FASTAPI · REDIS · FFMPEG · AWS ECS · CLOUDFORMATION

ROLE · BUILT AND SHIPPED THE APP

Shipped through v2.0.3 with EAS profiles and an OTA channel: faceted search over 20 filter dimensions, OTP registration, in-app account deletion and a single-fire 401 handler that turns concurrent failures into one logout.

Expo Routeraxios (single-fire 401)REST · OTA channel

11 screens · 20 filters · v2.0.3EXPO 54 · EXPO ROUTER · NATIVEWIND · REANIMATED

ROLE · BUILT PUSH, CHAT MEDIA AND RELEASES

A three-role app with an end-to-end FCM push pipeline and deep links, Socket.IO order chat with documents, and a 250 MB disk cache for chat media keyed by a stable hash of the S3 key.

Expo appSocket.IOExpress + RedisFCM push

EXPO 54 · REDUX TOOLKIT · SOCKET.IO · FCM · EXPRESS · REDIS

↗

ROLE · BUILT THE SESSION LAYER AND PAYROLL SCREENS

Sessions done right on both ends: rotating 90-day refresh tokens stored as SHA-256 hashes with reuse detection and a single-flight axios refresh interceptor, plus admin payroll screens.

Expo apprefresh rotationExpressMongoDB

EXPO 54 · ZUSTAND · EXPRESS · MONGODB

03 / STACK

$ tree ~/stack -L 1
stack/
├── languages/   typescript  javascript  python  sql  ✓├── frontend/    react  next.js  tailwind  shadcn/ui  tanstack query  next-intl  ✓├── backend/     node.js  express  prisma  socket.io  pg-boss  openai tools  ✓├── python/      fastapi  celery  pydantic  pandas  scikit-learn  scrapy  ✓├── mobile/      react-native  expo  eas  fcm  ✓├── data/        postgresql  pgvector  mongodb  redis  supabase  ✓└── cloud/       aws (ec2, rds, ecs, s3, cloudfront)  docker  github actions  ✓
7 directories, 34 tools, 0 regrets

04 / CONTACT

Let’s build something.

7.yudee@gmail.com GitHub ↗LinkedIn ↗X ↗

UdaySingh_