[ 00 ] _FULL_STACK_ENGINEER & SYSTEMS ARCHITECT
RAHUL
CHOUDHARY.
BUILDING SYSTEMS
THAT SCALE.
I engineer high-performance web platforms, resilient backends and AI-powered products — from architecture on the whiteboard to a green CI pipeline in production.
[ 01 ] _CAPABILITIES
What I Can Code.
Frontend_Core
Backend
- Node.js / Bun
- Python · FastAPI
- Go · gRPC
- Redis Streams
Databases
- PostgreSQL
- MongoDB
- Supabase / Firebase
- Pinecone · pgvector
AI / ML
- OpenAI · Anthropic
- LangChain · RAG
- Vector Search
- Whisper · TTS
Mobile & Cross
- React Native
- Expo
- PWAs
DevOps
- Docker · Kubernetes
- AWS · GCP · Vercel
- Terraform · GH Actions
[ 02 ] _SELECTED_WORKS
Ships That Fly.
#001
2M+ chats / mo
Nexus AI
Enterprise conversational AI platform with RAG pipelines, multi-tenant vector search, and streaming responses. Handles 2M+ conversations monthly across 40+ enterprise clients.
#002
12M req/day
Krypton OS
Distributed trading interface. Sub-40ms latency at 12M+ req/day.
#003
500M events/day
Atlas Analytics
Real-time SaaS analytics platform. 500M events/day through a custom ClickHouse pipeline.
#004
$14M GMV / yr
Vault Commerce
Headless luxury commerce stack — Stripe, headless CMS, edge-cached product API.
#005
100+ concurrent
Orbit
Real-time collaborative whiteboard. CRDT-based sync, 100+ concurrent users per board.
#006
60fps on mobile
Prism Engine
Web-based real-time 3D rendering pipeline with a WebAssembly-powered scene graph. Ships as an embeddable SDK used by 3 design tools.
#007
₹80Cr+ / mo
BharatPay Ledger
UPI-first payments + reconciliation stack for a Bengaluru fintech. Handles ₹80Cr+ monthly across NPCI rails with double-entry ledger and instant refunds.
#008
1.2L+ orders / mo
Swadeshi Kart
D2C commerce for 200+ Indian artisan brands. Hindi + English UX, COD-first checkout, WhatsApp order updates, Shiprocket integrations.
[ 03 ] _HOW_I_WORK
Ship In 4 Phases.
Discover
Deep dive into product, users, and constraints. Written scope in 48h.
Architect
System design, schema, API contracts, infra plan — no surprises later.
Build
Weekly demos, live staging, clean commits, tested every step.
Ship + Scale
Deploy, monitor, iterate. I stick around long after launch.
[ 04 ] _SERVICES
Engagement Modes.
MVP → Product
Zero-to-one builds for founders. Complete stack, auth, payments, dashboard, deploy — in weeks, not months.
Scale Architecture
Backends that survive traffic spikes. Queues, caching, sharding, observability, infra as code.
AI Integrations
LLMs, RAG pipelines, agents, vector search — plugged into your product with sane costs and guardrails.
[ 05 ] _SIGNAL
Clients On Record.
Rahul rebuilt our UPI checkout in 3 weeks. Conversion up 22%, RTO down 90%. Rare combo of speed and rigor — a real founder-friendly engineer.
Shipped our D2C stack from zero to 1L orders/month. Handled Razorpay, Shiprocket, WhatsApp — everything. Better than any Mumbai agency I've worked with.
He rewrote our legacy Django monolith into a clean Go + Next.js stack. P99 down 6×, infra bill down 40%. Just does the work.
Rahul ne humari EdTech platform ko scale kiya from 5k to 2L concurrent students. Zero downtime during JEE season. Absolute rockstar.
Built our entire AI copilot in 6 weeks — RAG, streaming, auth, billing. What our in-house team quoted 4 months for. No BS engineer.
Owned our ledger + reconciliation from day one. Zero payment mismatches in 8 months of production. I trust him with the money layer.
Rahul rebuilt our UPI checkout in 3 weeks. Conversion up 22%, RTO down 90%. Rare combo of speed and rigor — a real founder-friendly engineer.
Shipped our D2C stack from zero to 1L orders/month. Handled Razorpay, Shiprocket, WhatsApp — everything. Better than any Mumbai agency I've worked with.
He rewrote our legacy Django monolith into a clean Go + Next.js stack. P99 down 6×, infra bill down 40%. Just does the work.
Rahul ne humari EdTech platform ko scale kiya from 5k to 2L concurrent students. Zero downtime during JEE season. Absolute rockstar.
Built our entire AI copilot in 6 weeks — RAG, streaming, auth, billing. What our in-house team quoted 4 months for. No BS engineer.
Owned our ledger + reconciliation from day one. Zero payment mismatches in 8 months of production. I trust him with the money layer.
Owned our ledger + reconciliation from day one. Zero payment mismatches in 8 months of production. I trust him with the money layer.
Built our entire AI copilot in 6 weeks — RAG, streaming, auth, billing. What our in-house team quoted 4 months for. No BS engineer.
Rahul ne humari EdTech platform ko scale kiya from 5k to 2L concurrent students. Zero downtime during JEE season. Absolute rockstar.
He rewrote our legacy Django monolith into a clean Go + Next.js stack. P99 down 6×, infra bill down 40%. Just does the work.
Shipped our D2C stack from zero to 1L orders/month. Handled Razorpay, Shiprocket, WhatsApp — everything. Better than any Mumbai agency I've worked with.
Rahul rebuilt our UPI checkout in 3 weeks. Conversion up 22%, RTO down 90%. Rare combo of speed and rigor — a real founder-friendly engineer.
Owned our ledger + reconciliation from day one. Zero payment mismatches in 8 months of production. I trust him with the money layer.
Built our entire AI copilot in 6 weeks — RAG, streaming, auth, billing. What our in-house team quoted 4 months for. No BS engineer.
Rahul ne humari EdTech platform ko scale kiya from 5k to 2L concurrent students. Zero downtime during JEE season. Absolute rockstar.
He rewrote our legacy Django monolith into a clean Go + Next.js stack. P99 down 6×, infra bill down 40%. Just does the work.
Shipped our D2C stack from zero to 1L orders/month. Handled Razorpay, Shiprocket, WhatsApp — everything. Better than any Mumbai agency I've worked with.
Rahul rebuilt our UPI checkout in 3 weeks. Conversion up 22%, RTO down 90%. Rare combo of speed and rigor — a real founder-friendly engineer.
[ 06 ] _TIMELINE
7 Years, Zero Downtime.
Fractional CTO — Y Combinator Startups
Architecting AI-first backends and shipping MVP → Series A stacks for 4 active founders.
Lead Engineer — Series B Fintech
Owned the ledger + reconciliation stack. Cut P99 latency 6× and handled $400M in monthly volume.
Founding Engineer — AI SaaS
Built the RAG platform from a Colab notebook to a multi-tenant product doing 2M chats/mo.
Senior Full-Stack — Agency
Delivered 20+ production web apps across fintech, health, and D2C. Zero client churn.
Independent Developer — Solo
Started freelancing full-time. First 5-figure client contract at 21.
Uptime across production systems this year
In client revenue directly attributed to systems I built
Security incidents, data breaches, or missed SLAs
[ 07 ] _PRICING
Straight Numbers.
Founder-friendly pricing in INR & USD. No hidden retainers, no discovery-doc theater, no junior devs on your project. Fixed weekly / monthly rate — cancel anytime, keep everything shipped.
A single senior engineer (me), one well-scoped deliverable per week, working demo every Friday. Async-first with 2 live syncs — no meeting bloat.
Ideal for: one focused feature, an MVP screen flow, or a stuck engineering ticket you need shipped by Friday.
- →1 senior full-stack engineer
- →Slack / WhatsApp + 2 live syncs / wk
- →Working demo every Friday
- →Cancel or pause after any week
End-to-end product ownership — architecture, schema, APIs, frontend, auth, payments, CI/CD, deploy. You get a shipped product, not a Figma deck.
Ideal for: 0→1 products, funded pre-seed / seed startups, or founders who need one person to own the whole stack.
- →Full-stack architecture & delivery
- →Weekly design + product reviews
- →Auth, payments, infra & monitoring set up
- →Handoff docs + runbook on exit
Part-time technical leadership — roadmap, hiring, architecture reviews, on-call for critical calls. I plug into your existing team, not replace them.
Ideal for: seed / Series-A teams that need senior tech leadership without a full-time CTO salary yet.
- →2 days / week embedded
- →Hiring & code review for your team
- →Architecture + scaling decisions
- →Direct founder access on WhatsApp
GST extra for Indian clients · 50% advance, 50% on delivery · Free 30-min scoping call before we start
[ 08 ] _FAQ
Answers, Before You Ask.
How fast can we start? +
Usually within a week. I keep 1–2 open slots each month for new work. WhatsApp is fastest.
Do you work with early-stage founders? +
Yes — a lot of my work is zero-to-one. If you're pre-seed, I'll be honest about scope vs runway.
Can you own the whole stack? +
Frontend, backend, infra, CI/CD, auth, payments, monitoring — end-to-end. That's the default.
Do you sign NDAs and contracts? +
Always. Standard MSA + SOW for engagements over 2 weeks. I can work off yours or send mine.
What if I only need a code review or audit? +
That's the SPRINT tier. One week, deep review + written report + a live walkthrough call.
Do you work in my timezone? +
Based in IST but I keep 4 hours of overlap with US Pacific and full overlap with EU daily.
[ 09 ] _READY_?
Have a system worth building?
Ping me on WhatsApp with a 2-line pitch. If it's a fit, we're on a call within 24 hours.