Senior TypeScript/Node.js Developer — Field Service SaaS Platform

I'm building an AI-powered Field Service Management SaaS platform for facility service businesses (window cleaning, property maintenance, gutter cleaning, etc.). I have a working MVP with React frontend, Express API, PostgreSQL + Drizzle ORM, and an AI fleet management prototype using Claude API.

I'm looking for a senior developer to take this from MVP to production-grade — the architecture must be built to scale horizontally without limits. Think thousands of concurrent tenants, not dozens.

What exists:

Full database schema with 20+ tables, Drizzle ORM, Zod validation

React frontend with dashboard, CRM, planning (day/week/month views), visits, invoicing pages

Express API layer with TanStack Query hooks

AI Fleet Manager prototype (Claude API + Google Maps)

Multi-tenancy at application level (needs RLS upgrade)

Private GitHub repo ready for collaboration

Scope of work:

The MVP already has most UI components, database schema, and basic functionality in place. Your job is to take what exists and make it production-grade, plus build the missing pieces. Key areas:

Infrastructure & Security:

Production auth (migrate from Replit Auth to Supabase Auth, Clerk, or Auth.js)

PostgreSQL Row Level Security on all tenant tables

Refactor monolithic routes file into domain-separated modules

CI/CD pipeline, cloud deployment (containerized, horizontally scalable)

Connection pooling, caching, performance optimization

Core Platform — harden and complete:

CRM: customers, contacts, properties, service agreements

Scheduling: day/week/month views, vehicle allocation, capacity management

Visits: status flow, photo upload, field documentation

Field app (PWA): mobile-optimized daily routes, checklists, photo capture

Invoicing: auto-generation from visits, e-conomic API integration

Business cockpit: KPI dashboard with revenue, margin, utilization

AI Agent Layer — core differentiator:

AI Fleet Manager: deterministic postal code clustering + Claude API for route optimization, cancellations, sick leave coverage, capacity balancing (6 actions)

AI Customer Service Agent: automated email handling for cancellations, visit changes, customer inquiries

AI Sales Assistant: consistent sales tone, lead qualification, automated follow-ups

AI Optimization Agent: predictive scheduling, workload balancing, profitability analysis

All agents use Anthropic Claude API with tool-use pattern — each agent has defined tools that read/write to the database

Queue system and async processing for scalability

Must-have skills:

5+ years TypeScript + Node.js in production

PostgreSQL (RLS, migrations, performance tuning, connection pooling)

React + SaaS experience

Multi-tenant application architecture built for scale

Experience designing systems that handle high concurrency and large datasets

Experience building AI/LLM-powered features (Anthropic Claude or OpenAI — tool-use patterns, structured output, retry/fallback logic)

CI/CD and cloud deployment (containerized, horizontally scalable)

Nice-to-have:

Drizzle ORM / scheduling or fleet management systems

Google Maps / routing APIs

Danish market or EU/GDPR experience

To apply, please include:

1-2 relevant SaaS projects with TypeScript + PostgreSQL

How you've handled multi-tenancy before

Link to code sample / GitHub

Availability and preferred rate