YUDEE.DEVOPENING EYE
Uday Singh
FULL-STACK SOFTWARE ENGINEER
// BACKEND ENGINEER · NODE.JS

Uday
Singh_

I build production Node.js and TypeScript APIs — multi-tenant SaaS, payments, OAuth, idempotent queues — and I’m pretty good at squashing bugs. Try it →

BASED
Durgapur, IN
NOW
KajKarma, remote
SHIPPING
APIs · Queues · AWS
DEBUG.EXE— IDLESQUASHED 00TIME 00:30BEST 00

Animated ASCII field. Optional mini game: tap the bugs to squash them within 30 seconds.

✗ 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 · BACKEND ENGINEER · NODE.JS
// ARCHITECTURE
Scrapy workersHMAC batchespg-boss APIPostgres
SAAS · AI · 202601

SEObrix — AI SEO-audit SaaS

Express 5 + Prisma API (94 routes, 26 models) with an idempotent pg-boss queue: one job per audit, least-loaded routing and failover across crawlers, per-account spend caps. Gmail/Zoho OAuth with single-flight token refresh.

94 routes · 127 pytest tests · 16 CloudWatch alarms
EXPRESS 5 · PRISMA · POSTGRES · FASTAPI + SCRAPY · AWSvisit
Screenshot of InstaPath — multi-tenant legal CRM
SAAS · 202602

InstaPath — multi-tenant legal CRM

174 handlers over 36 models; a tenant-scope plugin throws on any query missing a tenant key. One-time login codes stored as SHA-256 hashes with lockout, MongoDB transactions for invoicing and lead conversion, audit logs archived to S3.

63 pages · 174 handlers · 68 test suites
NEXT.JS 15 · MONGODB · AUTH.JS · ZOD · DOCKERvisit
Screenshot of Uniglo Diamonds — web platform
B2B / B2C · AI · 2025–2603

Uniglo Diamonds — web platform

Inventory APIs (144 and 128 endpoints) with scheduled supplier sync and chunked bulk writes of 60k+ rows; an LLM sales assistant with 10+ tools over SSE, user-confirmed idempotent writes and 1,000+ tests.

✦ 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
Screenshot of I Want Jewels — a storefront in six languages
E-COMMERCE · 202604

I Want Jewels — a storefront in six languages

Multi-currency Stripe checkout with a daily FX rate and last-good fallback, per-order currency snapshots and gift cards keyed so webhook retries are safe; per-field LLM product translation.

6 locales · Stripe · JWT + OTP · admin panel
NEXT.JS · EXPRESS · MONGODB · STRIPE · AWSvisit
$ ls -la ~/projects --more
↗
ROLE · LED THE STOREFRONT · BUILT PHOTO SEARCH

Luxury jewellery storefront with a three-step custom ring builder, faceted catalogs over a cached Medusa commerce API, Stripe checkout, booking and a MapLibre store locator.

3-step ring builder · Medusa · MapLibreNEXT.JS 16 · MEDUSA V2 · PGVECTOR · STRIPE

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
↗
ROLE · BUILT THE SESSION LAYER AND PAYROLL SCREENS

Refresh-token rotation where reuse revokes every session, an IST-correct monthly payroll close that backfills missing rows, cron heartbeat diagnostics and health-gated deploys.

Expo apprefresh rotationExpressMongoDB
EXPO 54 · ZUSTAND · EXPRESS · MONGODB
↗

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
↗

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
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 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 · 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
↗
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
↗

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

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.comGitHub ↗LinkedIn ↗X ↗