AI Developer · Prompt Engineering & Automation

Sebastian
Bennis

I design and ship production AI systems - multi-agent platforms, realistic voice agents, and the apps around them. Not demos: products that businesses already use.

London, UK
Portrait of Sebastian Bennis

About

Self-taught,
shipping fast.

Sebastian Bennis working on code at his desk

I'm a self-taught developer who designs and ships real products end to end, across web, mobile and desktop. I've been building with AI for three years now, and it's become my everyday way of working - not a helper on the side, but the core of how I build. That time has made me fluent in prompt engineering: shaping the instructions and context that make models produce reliable, useful results, which I wire into products like multi-agent systems and voice agents.

I work at this every single day - always building new ideas, collaborating with other developers, and learning as I go. I care about whether something actually works for real people, and I move fast to get there. That's how I went from no formal training to shipping products people pay for. Honestly, it's all part of the journey.

  • French · native
  • English · fluent
  • Spanish · basic

Selected work

Products that run in the real world.

Bridge Voice AI

Voice agent

A realistic AI voice agent that answers business calls 24/7 - qualifies and routes leads, books appointments, takes notes and follows up by SMS and email. It can also make outbound calls to pitch clients. Live and used by UK businesses.

  • Voice AI
  • Telephony
  • OpenAI / Anthropic
  • TypeScript

Marketing AI Platform

Multi-agent system

A marketing engine run by up to twelve coordinated AI agents. It pulls live data from Meta and Google, audits business websites, finds prospect emails and phone numbers, scores how likely a deal is to close, sends cold emails, makes realistic outbound sales calls, and auto-posts across social.

  • Multi-agent
  • LangGraph / LangChain
  • Meta & Google APIs
  • n8n

Skip the Pitch

macOS desktop app

A desktop app that finds local businesses with weak websites, grades them, builds a bespoke showcase site to put in front of the owner, and tracks the deal to won - replacing the spreadsheet, site-checker, page builder and CRM in one app.

  • Tauri
  • macOS
  • Google Places / OSM
  • CRM

More I've built

AI writing assistantBrowser & desktop

Rewrites, translates, proofreads and summarises text right where you work - with tones, saved templates and history.

Live translation appiOS

Real-time translation built natively for iPhone.

Virtual try-onWeb

Virtual try-on for clothing shops.

Business websitesWeb

Full business sites with authentication, payments and subscription systems.

Tech & capabilities

AI

  • Prompt engineering
  • Multi-agent orchestration (up to 12 agents)
  • Inbound & outbound voice agents
  • AI wired to live business data

Languages

  • TypeScript / JavaScript
  • Python
  • Swift
  • Kotlin
  • SQL

Frameworks & platforms

  • React / Next.js
  • Node.js
  • React Native
  • Tauri
  • Supabase, Convex, Cloudflare

Features I build

  • Authentication
  • Payments & subscriptions
  • Deal / CRM tracking
  • Secure back ends

Have something to build?

Get in touch