Expertise · .NET, modernisation, applied AI

What I work on: .NET, modernisation, AI, Next.js

Fifteen years writing, taking over and shipping code, five of them on payment regulation at Euro-Information. Four domains, in the order the market asks for them. Each one states the stack, what I am trusted with, and what backs it up.

.NET 10 LTS

C# 14

Blazor / SignalR

Next.js 16

React 19

TypeScript

Tailwind v4

PostgreSQL

Six families of tools, no percentages

“.NET 95 %” measures nothing. Below are the families of tools I actually use on assignments, and nothing else. The technology names are the same in both languages: only the group labels are translated.

Back-end .NET

Where most of the fifteen years went: business applications, APIs and the data layer underneath them.

C#
.NET
ASP.NET Core
Entity Framework Core
SQL Server
PostgreSQL

Front-end

React and Next.js in TypeScript, on interfaces users spend their working day in.

React
Next.js
TypeScript
Tailwind CSS
Blazor

Build chain and infrastructure

Containers, pipelines and the servers they run on. I was the technical lead on the continuous integration rollout at Euro-Information.

Docker
Proxmox
CI/CD
Azure DevOps
Forgejo Actions
GitHub Actions

Quality and architecture

Automated testing, code review and the architecture decisions that keep an application maintainable past year three.

Automated unit testing
Continuous integration
Code review
Application architecture

Applied AI

A RAG that cites its sources, document extraction, a business assistant connected through MCP - inside your existing .NET applications.

Claude API
OpenAI API
Model Context Protocol
RAG
Mistral

How I integrate an LLM

Business domains

Payment regulation, billing and top-ups: domains where getting it wrong is expensive, and where it shows on a customer invoice.

PSD2
Payment & billing
Business applications
Project management

Where each of these has run

A capability list is worth what its receipts are worth. Six roles in fifteen years, five of them at the same group, from the most recent to the oldest.

Cedric Santiago DigitalSoftware engineer1.5 years and counting
Euro-InformationIT project manager3 years
Euro-Information DéveloppementApplication development analyst2 years and 4 months
EFORIT consultant2 years and 3 months
GE PowerEngineering apprentice1 year and 10 months
Alstom PowerEngineering apprentice1 year and 2 months

How an assignment runs

I join your team, your rituals and your repository: no method imposed from outside. The code and the secrets live in your Git organisation from the first commit, the build chain is the one your team already runs, and the operating documentation stays in the repository when I leave.

Invoicing is monthly, on days actually worked, at a single daily rate that is the same for everyone and is adjusted only to the length of the assignment. The figure itself is shared in my first reply, together with my availability. Travel along the Strasbourg - Sélestat axis is included; anywhere else, remote is the default and on-site presence is agreed before the assignment starts.

Frequently asked questions

What happens to the code you write?

It is yours. The code, the repository and the secrets sit with you from the first commit: I work inside your Git organisation, not mine, and I keep no copy. At the end of the assignment the access is handed back and the operating documentation stays in the repository.

Do you work through consultancies?

Yes: directly, through a consultancy or through a freelance platform, at the same rate. The industrial assignment running since April 2025 goes through a partner consultancy. If your supplier list requires an intermediary, say so in the first exchange - it changes neither the daily rate nor the way I work.

Will you take over an application with no tests?

That is the most common case, and a normal starting point. The order does not change: characterise before modifying. First non-regression tests on the critical paths, then a continuous integration pipeline that fails when something breaks, then refactoring in batches. No big-bang rewrite: it ends badly, and it shows six months later.

Do you still take front-end only work?

Yes, in Next.js 16 and React 19, but it is a support skill rather than the main axis: the local market asks first for .NET and for legacy take-over. I take front-end assignments when they sit on a .NET back-end, when a product team needs a TypeScript reinforcement, or when a public site has to be server-rendered.