# Manuel User

Manuel User is a remote worker on Himalayas, AI Booking Agent & Sales Sync at Japanese Head Spa Marbella, based in Uruguay.

Source: https://himalayas.app/@manueluser12

```text
Full-Stack and AI Engineer building a production WhatsApp booking agent that handles appointments, deposits, and gift cards.
```

| Detail | Value |
| --- | --- |
| Availability | Looking for a job |
| Location | Uruguay |
| Authorized to work in | Uruguay |
| Salary expectations | 50k+ USD |
| Job categories | AI Engineer, Full Stack Engineer |
| Skills | AI Engineering, LLM APIs, Agent Design, Function Calling, Eval Driven Development, LLM Regression Automation, Prompt Engineering, Prompt Caching, Conversation Orchestration, WhatsApp Business API, Cloudflare Workers, Cloudflare Durable Objects, Cloudflare D1, Cloudflare KV, Cloudflare Queues |

## About

```text
I built and run a production booking agent for Japanese Head Spa Marbella that handles customer conversations, availability, appointments, deposits, and gift cards on WhatsApp and Instagram. Its 14 function-calling tools use schema validation and business rules, with 234 multi-turn scenarios and 799 intent-classification cases in its evaluation suite.

At DSpot, I cut First Contentful Paint by 40% on Fusion, the Sky Ecosystem’s public transparency dashboard, and designed a TypeScript and Tailwind design system that increased team development velocity by 30%. Earlier, I reduced API payload size by 50% at Fulltime and integrated Prebid.js header bidding at E-planning.
```

## Experience

### AI Booking Agent & Sales Sync (current)

Japanese Head Spa Marbella. Jan 2026 - Present

```text
Built and run a production conversational agent on WhatsApp and Instagram that handles bookings, availability, deposits, and gift cards end to end. Designed the agent around 14 function-calling tools with schema validation and deterministic business rules.
```

Skills: TypeScript, Cloudflare-Workers, LLM, WhatsApp-Business-API, Cloudflare-Durable-Objects, Queue, Wix-Bookings, GoHighLevel-CRM, OpenRouter, Claude, Gemini, Prompt-Engineering, Eval-Driven-Development

### Senior Full Stack Engineer

DSpot. Dec 2021 - Oct 2026

```text
Cut First Contentful Paint by 40% on Fusion, the public transparency dashboard of the Sky Ecosystem, by owning the frontend architecture and server/client rendering split in Next.js. Increased team development velocity by 30% by designing and maintaining the Powerhouse Design System.
```

Skills: TypeScript, React, Next.js, Tailwind, Design-Systems, Frontend-Architecture, Performance-Optimization

### Software Developer

Fulltime. Nov 2019 - Sep 2021

```text
Reduced API payload size by 50% by designing and optimizing GraphQL schemas and resolvers in Node.js. Shipped production React Native apps for industrial clients with real-time inventory management, logistics tracking, and offline-capable data flows.
```

Skills: NodeJS, GraphQL, Apollo, React-Native, REST-API-Design, PostgreSQL, MongoDB

### AdTech Developer

E-planning. Aug 2018 - Nov 2019

```text
Integrated Prebid.js header bidding to make ad auctions more competitive on live inventory, increasing client ad revenue.
```

Skills: Prebid.Js, Header-Bidding, AdTech, JavaScript

## Education

### Central University "Marta Abreu" of Las Villas

B.Sc., Computer Science. 2010 - 2014

```text
B.Sc. in Computer Science from Central University "Marta Abreu" of Las Villas, Cuba, from 2010 to 2014.
```

## Tech stack

- GitHub Actions
- React Native
- PostgreSQL
- MongoDB
- Node.js
- Next.js
- NestJS
- Tailwind CSS
- Material-UI
- Jest
- Cypress
- React
- JavaScript
- HTML5
- Apollo
- Gemini
- GraphQL
- Redux
- Zustand
- Vercel
- TypeScript
- React Testing Library
- Git
- Docker
- SQL
- Cloudflare Workers
- TanStack Query
- Cursor
- Cloudflare D1
- OpenRouter
- Claude Code
- SWR
- Express
- Claude
- OpenAI
- CSS3

To contact Manuel, message them from this profile with a Himalayas employer account: [Hire on Himalayas](https://himalayas.app/hire).

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