Architecture & Deployment

System design, dual environments, and the calculation pipeline

System Architecture

Browser

HTTPS request

→

nginx

SSL + static files

→

Node.js API

Port 3100

→

PostgreSQL

Port 5433 (shared)

Static frontend served directly by nginx • /api/* proxied to Node.js • Puppeteer/Chromium for PDF generation

Local Development

Docker Compose with 4 containers
http://localhost:8004
Ports: nginx=8004, backend=4002, frontend=5173, postgres=5434

Production

Bare Node.js on DigitalOcean droplet
https://wit.ipnoelp.com
Port 3100, shared PostgreSQL, Let's Encrypt SSL

PPS Space Calculator — Building block quantities per floor (user input)

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Tech Breakdown — Block qty × equipment multiplier → equipment quantities by category

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Network Design — Add site-size-specific equipment (routers, switches, WAPs)

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Regional Pricing — Equipment quantities × unit costs for the project's region

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Cost Formulas — Installation (25%), BAU (60% of CAPEX), ITO (10%), PPS (2%), Contingency

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15-Row Cost Summary — Including/Excluding Network variants + Budget Breakdown

Layer	Technology
Frontend	React 18, TypeScript, Vite, TailwindCSS, React Query
Backend	Node.js 20 (ESM), Express, TypeScript
Database	PostgreSQL 15 (shared with CMS)
PDF	Puppeteer + Chromium (snap)
Excel	xlsx library

Component	Status	Notes
Deployment	Complete	Running at wit.ipnoelp.com
Calculation Engine	85%	BAU fixed, missing decom formula + equipment mappings
Reference Data	90%	6 retail building blocks unmapped
Validation	Waiting	Email sent to Craig 2026-02-22