One requirements document became a ServiceTitan-class HVAC platform in 6 days and $1,609 of AI spend

A complete, running field service platform, generated by our AI-native pipeline here in Brocoders. No human wrote the CRUD, the pages, the migrations, or the tests

TL;DR

One requirements document went in. A running FSM platform came out: 82 database models, 343 API endpoints, 88 screens, ~454 automated tests. The generation cost $1,609 in AI spend across 369 model calls over ~5.5 days, versus 6 to 12 months and six figures for a comparable custom build.

The platform

One requirements document went in. A complete, running FSM platform came out. No human wrote the CRUD, the pages, the migrations, or the tests.

The fastest way to judge a claim like that is to look at the thing. So here is the platform itself, role by role. The generated system ships with 4 working logins: admin, dispatcher, technician, and customer. Each one gets its own version of the product, scoped by permissions, and each one covers a complete working day.

Admin

The owner's view of the whole operation: revenue trend, jobs by status, A/R aging, and revenue by lead source on the dashboard, plus full lists for work orders, customers, and field findings flagged for the office to act on.

Fieldera admin login: dashboard, work orders, customers, findings

Dispatcher

The daily surface a dispatcher lives in: an hour-by-hour board of every technician's schedule, an unassigned queue by priority, route optimization per technician, and instant reassignment with confirmation.

Fieldera dispatcher login: dispatch board, work order assignment, route optimization

Technician

A field-ready "My day" view on phone and desktop: a time clock for work, break, and drive states, the day's scheduled jobs, and full work order detail down to trade-specific fields and assignment history.

Fieldera technician login: my day, time clock, work order detail

Customer

A self-serve portal for the client: account balance and open work orders at a glance, upcoming appointments, and an invoice history with online payment and PDF download.

Fieldera customer login: portal dashboard, invoices, appointments

This is a working system with dispatch, invoicing, payroll, inventory, refrigerant compliance, load calculations, and marketing attribution. The scale of what shipped is engineering evidence, and each line below is work a development team normally does by hand:

What shippedThe hand work it replaces
82 database models plus 41 enums, a 2,200-line schema, 74 real migrationsWeeks of schema design and migration writing
88 web routes and screens, 343 API endpoints across 74 backend modulesMonths of endpoint and UI implementation
~454 automated tests (48 API unit specs, 81 Playwright end-to-end suites)Test authoring most projects defer or skip
Stack: NestJS 11, Prisma 6, PostgreSQL, Next.js 16, React 19 · live Stripe, Twilio, QuickBooks Online integrations plus an in-product AI copilotArchitecture and integration work by senior engineers

This is the surface area a development team would spend months designing, writing, and testing by hand.

Why we ran this experiment

Operators of field service businesses are handed two options: rent generic per-seat SaaS you never own, or commission a custom build that takes months and six figures. Here in Brocoders we wanted to test whether that tradeoff still holds, so the Fieldera team ran an internal experiment: one requirements document, one AI-native generation run, and every artifact kept for inspection.

Custom build$25K–$150Kfor an MVP over 16 to 20 weeks; six figures for full parity, then 6 to 12 months to a running system. You own it.
ServiceTitan$35K–$110Kfirst year for a 10-technician team: $250–$500 per tech per month over 12 months, plus $5K–$50K setup. The bill rises with every hire. You never own it.
AI-native generation$1,609in AI spend, ~5.5 days of generation; 4 to 5 weeks for a fitted deployment. Yours, a standard inspectable monorepo, with usage-based pricing that stays flat as you hire.

The AI spend is the generation step, and a real deployment adds review, hardening, data migration, and support. Even so, the step that used to cost months now fits on a corporate card.

What separates this from vibecoding

"I vibecoded an app" stories are everywhere. Trust comes from the seams, so here are ours: the questions the system asked, the plan it built, and the checks it ran on itself.

01

Discovery, not dictation

The system generated 10 clarifying questions from the spec: 5 blockers and 5 nice-to-haves, each explaining why it matters before asking. It is the same paper trail a good business analyst leaves.

Q2 (blocker): "Should Manual J/D/S load and duct calculations be built in-house or integrated via a third party?"→ Build in-house
Q4 (blocker): "Which accounting system should the MVP integration target first?"→ QuickBooks Online
Q5 (blocker): "Which CPaaS provider and which payment processor should v1 wrap?"→ Twilio + Stripe

Every answer was locked back into the requirements as a decision before a line of code existed.

02

Planning like a tech lead

The locked requirements decomposed into 23 epics and 96 user stories, phased MVP → Phase 2 → Phase 3. 82 of 96 stories declared explicit dependencies on earlier stories. A real ordered backlog, with payroll waiting on invoices and dispatch waiting on work orders and technicians.

03

Build one story at a time, check your own work

25 QA and verifier passes and 10 automated repair passes fired during execution. 95 of 96 stories completed. The output is a conventional git history, roughly 82 commits, about one per story, readable feature by feature.

The honest limits

·The field app is a PWA, a deliberate PWA-now, native-later decision.
·"ServiceTitan-class" describes the spec's ambition. The delivered reality is the countable one: 82 models, 88 routes, 343 endpoints.
·1 of 96 stories did not complete. It is documented in the plan, and you can read exactly which one.
·AI-generated and inspectable beats AI-generated and magic: a standard NestJS + Next.js monorepo, reviewable, auditable, and yours. Start with the git log.
·This was an internal proof. A real client deployment runs about 4 to 5 weeks, because fit work (workflow mapping, integrations, training) is where the value is. Fieldera is early-stage and taking design partners.

What this changes

For operations managers

Custom-fit software is now the faster and cheaper option. The baseline for this surface area was months and six figures, or per-seat SaaS you never own. This run cost $1,609 in AI spend across 369 model calls in ~5.5 days of generation. With usage-based pricing, growth stays affordable: every new hire costs the same to run.

For platform founders

The build-cost floor for vertical operations software just moved. An MVP scope that used to justify a seed round's worth of engineering is now a generation run plus fit work. Scope your MVP against what generation covers, and spend the human budget on the parts that differentiate you.

FAQ

Can AI really build a complete field service management platform?

Yes. This build produced a running platform with 82 database models, 343 API endpoints, 88 screens, and about 454 automated tests, all generated from one requirements document. The repo is countable and inspectable.

How much did it cost to generate this FSM platform?

The generation cost $1,609 in AI spend across 369 model calls.

How long did the build take?

About 5.5 days of wall-clock generation. A fitted client deployment runs 4 to 5 weeks, because workflow mapping, integrations, and training are where the value is.

Is the generated code maintainable?

It is a standard NestJS and Next.js monorepo with about 454 tests and a conventional git history of roughly 82 commits, about one per story. Any developer can clone it and read the product being built feature by feature.

Is this a native mobile app?

The field app is a PWA today, a deliberate PWA-now, native-later decision.

How is this different from no-code or vibecoding?

The pipeline asked 10 clarifying discovery questions before building, planned a dependency-ordered backlog of 23 epics and 96 stories, and ran 25 QA and verifier passes plus 10 automated repair passes during execution. Vibecoding skips all three.

Fieldera is taking design partners

Bring your operation's requirements and we will show you what a fitted deployment looks like in 4 to 5 weeks. Write to talk@fieldera.ai.

Want to see how an AI does this without the wheels coming off? The orchestrator deep-dive is coming next.

Become a design partner