Full Stack Product Engineer
AmanPrajapati
I build software that real businesses actually run on — ERP platforms, order systems, mobile apps. Solo tech lead at a food distribution company, shipping code that goes straight to the CFO's dashboard.
- Role
- Full Stack Product Engineer
- Base
- Mumbai, India
- Coord
- 19.076°N 72.877°E
Live in production — open the software
422
REST Endpoints
42
Mongo Collections
20
RBAC Roles
172K
Lines in Production
62
Mobile Screens
10
Products Built
I don't just write code — I build software businesses run on.
Based in Mumbai, India. I take products from a blank repository to real users, owning architecture, infrastructure, security and AI integration — and I stay on them after they ship.
Credentials
BSc Computer Science
Foundation
MCA
Master of Computer Applications
Production Systems
Designed, shipped & owned
Cloud & Infrastructure
Deployed & scaled
Certifications
- MERN Stack ProgramFull-stack foundation
- AWS Cloud Internship ProgramCloud fundamentals
The journey
- 01
BSc Computer Science
The fundamentals — algorithms, systems, the why beneath the what.
- 02
MCA
Master of Computer Applications — depth in software engineering.
- 03
Mobile Application Developer
Shipping Flutter apps to the Play Store and App Store.
- 04
Full Stack Engineer
Owning the stack end-to-end — frontend to database to deploy.
- 05
Enterprise Product Builder
Architecting production platforms that run real businesses.
- 06
AI Systems Engineer
Embedding Gemini, vector search and AI workflows into products.
11 builds. 4 live in production.
Enterprise platforms, mobile apps, an ERP core, an event-driven data pipeline, an offline AI app and a game-engine port — each taken from an empty repository (or a Windows-only one) to something that runs. Open any row for the architecture diagram and the reasoning behind it.
A fix of mine is in Open Rails.
I ported a Windows-only train simulator to run natively on my Mac, then took the part that was useful to everyone back to the official project. Every claim below links to somewhere you can check it.
1
Pull request merged into the official Open Rails repository
0
Wine or virtual machines at runtime
2
Real routes loaded and driven on a Mac
GPLv3
Licence kept, source public
How it happened
01The problem
Open Rails is an open-source train simulator written in C#, built for Windows. On a Mac it needed Wine or a virtual machine.
02The port
I replaced the Windows-only pieces (graphics, fonts, settings, audio), fixed a loading freeze caused by two threads waiting on each other, and got real routes running natively on Apple Silicon.
03Giving it back
I announced it to the Open Rails team. Their developers read the code, asked questions, and asked for small focused pull requests. My first one was reviewed and merged.
04Making it usable
A user reported a black screen: the source alone does not contain the compiled shaders. I published a ready-to-run download, a user manual, and a Mac app whose menu follows the Windows one.
Check it yourself
Ten stages, forty states, twenty roles.
An ERP-class order pipeline that a real business runs on. Every stage name, state, role, upload type and notification rule below is read straight off the running system.
Order Entry
Sales · Sales Executive
Booked on the mobile app in the field or on the web console, with PO copy and site photos attached at source.
PendingBook OrderDraftFuture Ordered
Sales Hub
NSM · RSM · ASM
The sales line reviews and places the order; future-dated orders are parked until their release window.
Placed Order
STN Planning
STN Planner
Internal stock transfers are planned separately from customer orders, then re-enter the same pipeline.
Pending STN Planning
Credit Approval
Credit Control · Gemini risk score
Exposure, ageing buckets and overdue ratios are scored; low risk auto-approves, critical is held and escalated.
Pending Credit ApprovalCredit ApprovedOn HoldRejected
Warehouse Selection
WH Manager
Stock is checked per warehouse; an order that can't be served from one site splits into per-warehouse child orders.
Pending WH SelectionWH AssignmentWarehouse Assigned
Packing & Batch Allocation
WH Manager · Warehouse staff
Picking against specific batches with FEFO ordering and decimal quantities for weighed goods; shortfalls raise a residual order.
Pending PackingPacking StartedPart PackedPackedBackorder
Quality Control
QC Head
Physical check with photo evidence attached to the order; a rejection routes straight back to packing.
Pending QCQuality ApprovedQuality Rejected
Logistics Cost
Logistics Lead · Hub Lead
Freight, loading and insurance are itemised. Any order whose shipping exceeds 15% of its value is held for admin review.
Pending Logistics CostCost AddedPending Admin Review
Invoicing
Billing
Invoice and e-way bill generated, with the document mailed out and stored on the CDN.
Ready for InvoicePending InvoicingInvoicedPending E-Way Bill
Dispatch, Delivery & Acknowledgement
Dispatch · Delivery Team · Driver
Manifest, seal number and vehicle assigned, then live GPS tracking until the customer signs — including partial acceptance and returns.
Ready for DispatchDispatchedIn TransitOut for DeliveryDeliveredPart AcceptedReturned
A transition validator holds the whole graph — 40 named states with an explicit allow-list of next moves each. An order cannot skip credit, or get invoiced before QC clears it.
Systems, not scripts.
I make the architecture decisions before the first line of code, and I stay with the system after it ships.
What I design for
Scalable Backend Architecture
Modular, middleware-driven services that grow without rewrites.
Realtime Systems
Socket.IO rooms streaming sub-second updates to every client.
RBAC Security Design
20+ roles, permission guards and a secure middleware chain.
Audit Logging Systems
Every state change traced — who, what, when, immutable.
Notification Engines
FCM push, web push and email across one unified pipeline.
AI Systems
Gemini risk scoring, embeddings and RAG-style retrieval.
Cloud Infrastructure
Cloudflare, Nginx and PM2 on DigitalOcean — Prod & UAT, self-rolling-back deploys.
Data Pipelines
Event streams, exactly-once effects, aggregation pipelines and index design.
How a feature actually ships
- 01
Understand
Sit with the people who will use it, then write down the data, the edge cases and what 'done' means.
- 02
Design
Data model, API contract and the trade-offs — decided before the first line of code.
- 03
Build
I write it, using AI tools like Claude and Cursor to move faster on the routine parts.
- 04
Review & test
Every line read, edge cases tried against real-shaped data on UAT. Nothing ships unreviewed.
- 05
Ship & run
Deployed with a health check and rollback, then watched on Sentry and PostHog and fixed with the business.
I own what I ship.
I use AI tools to move faster. The design, the review and what happens in production after release are my responsibility.
Tools I use
Claude · GPT · Gemini · Cursor
The full stack behind it.
Everything below is something I've shipped with, not something I've read about.
Frontend Engineering
01Web
Angular · React · Next.js · TypeScript · Vite · Tailwind CSS · Framer Motion · GSAP · Responsive Design · PWAs
Mobile
Flutter · Provider · Hive · SQLite · Local Notifications · Google Maps SDK · Biometric Auth · Offline-First · Cross-Platform · Android Deploy · iOS Deploy
Backend Engineering
02Node.js · Express.js · NestJS · TypeScript · REST API Design · JWT Auth · RBAC · Middleware Architecture · Repository Pattern · Service Layer · Audit Trails · Excel Processing · File Upload · PDF Generation · Email Services · OTP Auth · Real-Time APIs · API Security · Rate Limiting · Request Validation · Error Monitoring · Background Processing
Databases
03MongoDB · Mongoose · PostgreSQL · TypeORM · Redis · Aggregation Pipelines · Indexes · Query Optimization · Schema Design · Data Modeling · SQLite · Hive · Local Storage
Real-Time Systems
04Socket.IO · Redis Streams · Consumer Groups · Transactional Outbox · Exactly-Once Effects · Backpressure · Live Notifications · Real-Time Dashboards · Live Order Tracking · Mission Tracking · Warehouse Updates · Instant Sync · Cross-Platform Sync
Cloud & Infrastructure
05DigitalOcean Droplets · Oracle Cloud VMs · DigitalOcean Spaces · CDN Architecture · Nginx · PM2 · Cloudflare (WAF, edge rate limits) · Origin firewall (UFW) · GitHub Actions CI/CD · Health-checked auto-rollback · Docker Compose · AWS S3 + Object Lock · Linux Administration · SSL Management · Server Deployment · Production Monitoring · Environment Management · Infra Scaling
Third-Party Integrations
06Google Gemini AI · Firebase Cloud Messaging · Firebase Admin SDK · Google Maps Platform · Resend Email API · DigitalOcean Spaces · CDN Delivery · Sentry · PostHog · Razorpay
AI Engineering
07Google Gemini · Risk Analysis Engine · Credit Assessment · Business Intelligence · AI Daily Briefings · AI Alert Analysis · TensorFlow Lite · Google ML Kit · On-Device Inference · Face Embeddings · Prompt Engineering · Backend AI Proxy · Secure API Routing · Decision Support
Security Engineering
08JWT Auth · RBAC · bcrypt · OTP Verification · Token Validation · API Protection · Permission Matrix · Audit Logging · Secure File Upload · Signed Short-Lived URLs · Secrets Management · SSH Hardening · Incident Response · Backup & Restore Drills · Session Security
Enterprise Architecture
09422 REST Endpoints · 20 RBAC Roles · 42 Mongo Collections · 10-Stage Order Workflow · Multi-Warehouse · Order Lifecycle · Credit Control · Inventory · Dispatch · Logistics · Route Tracking · Customer Mgmt · Audit Mgmt · Analytics · Sales Hierarchy
Let's build something.
Have a product to architect, a system to scale, or a team to strengthen? I'm one message away.
- Phone
- +91 8369259104
- in/aman-prajapati
- Resume
- Open resume