Preamble
A working notebook kept by a developer who treats artificial intelligence as an engineering material - not a promise.
Software that
reasons for itself.
I ship AI into production web apps - for teams that need to automate, scale, and deliver smarter interfaces. End to end, from embedding to pixel.
- Base
- Barcelona / Paris
- Practice
- Full-Stack x AI
- Since
- 2019
- Engagements
- Retainer / fixed
- 00
Query
fn. 00user - context
- 01
Embedder
fn. 01 - 3072dtext-embedding-3
- 02
Retrieve
fn. 02 - Postgrespgvector - hybrid + rerank
- 03
reason
fn. 03 - reason + actClaude - JSON tools
- 04
Verify
fn. 04 - regressionsZod - evals + LLM judge
Three practices,
Catalogue of instruments
- Frontend
- React - Next.js - TypeScript - Tailwind - Three.js
- Backend
- Node - Express - Python - FastAPI - PostgreSQL - Mongo
- AI
- OpenAI - Anthropic - LangChain - pgvector - RAG - Evals
- Ops
- Docker - AWS - CI/CD - Observability - Stripe
Five systems,
put to work.
AI reconciliation - freelance client work
Map Align - a 5-act pipeline
Reconcile volatile external sources (websites, maps, PDFs) with an internal database of thousands of physical spaces, without the AI ever hallucinating deletions. The deterministic engine decides; the LLM reviews and can only downgrade.
Stack - TanStack - Drizzle + Postgres - OpenAI - Zod - Turborepo
Legaltech - production
Verixa
Legal-document checker wired into Legifrance and Judilibre. Structured extraction, citation verification, alerts on outdated case law. Built for firms that can't afford to be wrong.
Stack - Next.js - FastAPI - pgvector - Anthropic - RAG
Ops - B2B SaaS (client engagement)
PMS - project mgmt, rewired
Project management whose reporting writes itself: weekly digest, drift detection, client brief. The team stays in their tool, the board gets a readable brief every Monday.
Stack - Next.js - Node - Postgres - OpenAI - Stripe
Mobile + Admin - client work
DEFIM - maritime learning
An exam-prep platform for maritime certifications: an iOS/Android app and a web admin, designed and shipped end to end. Timed quizzes, mock exams, rich pedagogical content, and a drag-and-drop admin workflow to orchestrate the whole thing.
Stack - Expo / React Native - Next.js - Supabase - dnd-kit - Zod
Methodology and references available on request - contact@pauldosser.fr.
Seven years of writing,
by hand.
- 2023 - present
Freelance - Full-Stack x AI
AI integration and product engineering engagements for scale-ups and studios: audit, prototype, production rollout, team support.
Barcelona / Paris - 2024 - present
Team Lead - Two.Zero
Leading a product and engineering team: scoping, architecture, delivery, technical coaching. Focus on AI integration and production reliability.
Barcelona - 2025 (6 months)
Full-Stack Developer - NTT DATA
Public Procurement Data Space (PPDS) project for the European Commission: SPARQL queries, Virtuoso knowledge graphs, front-end and back-end work supporting public data accessibility and transparency.
Barcelona - hybrid - 2022 - 2024
Full-Stack Lecturer - Epitech
Teaching modern web architecture, supervising student projects, engineering practice.
Barcelona - 2019 - 2022
Developer - CertiPair
Certification platform: product, API, client-facing interfaces. First scaling experience, first real production incidents.
Paris
Three acts. No magic.
Audit and hypothesis
I sit inside your product for two to three days. I leave with a testable hypothesis, a named risk, a demo that's doable in two weeks.
- Product / data workshops
- Risk map
- Eval plan
Build and evaluate
Short sprints, weekly demos, automated evaluations from the first commit. We measure before celebrating - and we keep the numbers.
- RAG / tool pipelines
- Guardrails and observability
- Eval-driven iteration
Into production
Deployment, monitoring, handover to your team - or ongoing support. The goal: the system holds on a Monday morning without me.
- CI/CD and infrastructure
- Dashboards and alerts
- Team handover
“A good AI integrator spends 70% of their time on what surrounds the model - data, guardrails, interface, evaluation. The rest is a matter of taste.”
What people ask first
Frequently asked.
The five questions that come up most often before a first call. If yours is missing, write directly - I always reply.
- Do you ship production RAG systems?
- Yes. Paul Dosser designs and ships full RAG pipelines - pgvector hybrid retrieval with reranking, typed tools with Zod, automated evaluations and tracing via Langfuse - for European clients since 2023. Every project lands with its eval suite, not just a demo that works on Monday.
- Are you available for freelance work in Barcelona or remote?
- Yes. Based between Barcelona and Paris, I work as a freelance for clients in France, Spain, and the wider EU, on-site or remote. I take full-time on a scoped engagement, fixed-price projects, or a few days per week on retainer depending on the contract.
- Which LLM providers do you integrate in practice?
- Mostly Claude (Anthropic) and OpenAI models for reasoning and structured generation, with text-embedding-3 for embeddings. I pick by use case: reliable function-calling, latency, cost per token, data compliance. The stack is provider-agnostic - the same pipeline can swap from one to another by reconfiguring an adapter.
- How do you evaluate AI system quality in production?
- I treat prompts like code: versioned eval sets, LLM judges for qualitative metrics, deterministic rules for hard constraints (citations, formats, required fields), and continuous comparison through Langfuse. Every prompt or model change runs through the suite before it reaches production, which kills silent regressions.
- Which stack do you typically ship on?
- TypeScript end to end: Next.js (App Router, React Server Components) on the front, Node or FastAPI on the backend, PostgreSQL with pgvector for the vector store, Zod for AI contracts, and Langfuse for LLM observability. Hosting on Vercel or the client cloud depending on data residency constraints.
A letter
Let's build
something together.
If you have a product that could reason a little better, a process a model could lift off your team, or an AI hypothesis waiting for proof - write. I answer within 48 hours with an honest, free, and often more useful-than-expected opinion.
- Paul.