Android + NestJS + React platform, on-device AI — fixed-price quote, 3 deliverables

WHAT WE ARE COMMISSIONING A field operations platform for regulated technical inspections. It dispatches work to crews, guides each visit step by step by voice, captures photographic evidence with quality control enforced on the phone, and delivers it to a control centre in real time. This is not an hourly role. We are asking for a fixed-price quote on three defined deliverables, each with its own date and its own acceptance criteria. The technical design is finished and we share it before you quote, so you are pricing a specified scope rather than an idea. A separate specialist supplies the vision models. Your package integrates them and builds everything around them. THE THREE DELIVERABLES D1 · Mock-up — due 2 October 2026 The full flow working end to end, in front of the customer: guided capture on the phone, evidence travelling to the console, the reviewer marking a finding, the result returning to the phone. Detection is simulated at this stage and declared as such. It must be built on the same codebase as D2 and D3 — same app, same service, same console — with minimum scope. Built as a throwaway demo it means doing the work twice, and we will not accept it that way. D2 · Phase 0 — 1 to 30 November 2026 The pilot operating for real with a first set of crews. · Android app: assigned tasks, geofenced arrival, guided capture with light, focus and stability control, on-device anonymisation before anything is stored, full offline operation with batched sync · Backend: modular API, multi-tenant, roles and permissions, evidence ingestion, review queue · Console: manual assignment and reassignment, review queue, marking findings on the image, procedure editor, light fleet tracking on an operations map, traceability reports In this phase the app detects nothing on its own. A person marks the finding in the console and the result travels back to the phone. D3 · MVP — closes around 15 January 2027 On-device detection goes live. The app runs the anomaly model and alerts on the spot without waiting for the reviewer; the device generates the alert; the console stops receiving detection tasks and starts receiving alerts. Human review stays available for as long as the customer wants it. This must not change the architecture — and that is the point of the requirement below. THE REQUIREMENT THAT SHAPES THE PRICE The platform is specified and built before the model exists. So D1 and D2 have to leave the entry points already built: the model deployment contract, the autonomous alert states, and the screen that renders the result over the image. If those are not in place, D3 means rebuilding the app and requoting the work. Price D1 and D2 with that in mind. WHAT IS ALREADY DEFINED, AND SHARED BEFORE YOU QUOTE This is not a blank page. 46-route API contract across 53 operations with an executable OpenAPI spec, data model, state machines, event contract, screen inventory with navigable mockups, role and permission matrix, 30 user stories with acceptance criteria, and a security and data-residency specification. Chilean data protection law (Ley 21.719) is a hard constraint, not a nice-to-have. WHAT IS NOT IN THIS PACKAGE Route optimisation, continuous live fleet tracking, automatic reassignment by proximity, and the conversational assistant. Do not price them. If you want to quote them separately as an option, say so, but keep them out of the package total. THE THREE HARD PARTS, SO YOU PRICE THEM AND NOT THE EASY ONES 1. The procedure is data, not code. Steps, required evidence, time limits and voice prompts live in a JSON recipe the customer edits from the console. Adding a photo to a sequence must not require a new app release. 2. Offline-first for real. Crews work where there is no coverage. Evidence and events queue on the device and sync in batches with idempotency keys. A lost or duplicated event breaks the audit trail, which is what the customer is buying. 3. Privacy by design. Faces are blurred on the phone before anything is stored or transmitted, and the system produces a verifiable record proving it. WHAT YOUR TEAM NEEDS TO COVER Android native with CameraX and offline synchronisation · TypeScript with NestJS, PostgreSQL and multi-tenant isolation · React for the console. One team or a small studio; if you subcontract part of it, tell us which part. English or Spanish, both fine. HOW TO QUOTE Send a price per deliverable — D1, D2 and D3 separately — plus the total. Timings are tentative and the final duration is yours to propose; if you think a date is unrealistic, say so now rather than in December. Along with the numbers, answer three things briefly: 1. Which of the three hard parts you consider riskiest, and how you would de-risk it 2. One thing you would change in our reference stack (Kotlin / NestJS / PostgreSQL / React) and what it solves 3. What you would need from us to hold the 2 October date We send the full technical brief to anyone whose answer shows they read this. Generic proposals will be ignored.