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Freelance · Paris & Remote

Koa
Dev Freelance Fullstack Developer & Tech Lead in Paris

Senior Fullstack Developer & Tech Lead with 15+ years of experience in startups. Cloud architectures, distributed systems, AI & high-traffic applications — I turn your complex ideas into scalable products.

15+
Years of exp.
50+
Projects delivered
4yrs
Freelance
TypeScript
React
Node.js
AWS Lambda
Cloud Architecture
Serverless
PostgreSQL
Kubernetes
GCP
GraphQL
CI/CD
Tech Lead
AI / LLM
TypeScript
React
Node.js
AWS Lambda
Cloud Architecture
Serverless
PostgreSQL
Kubernetes
GCP
GraphQL
CI/CD
Tech Lead
AI / LLM

What I can
do for you

Cloud Architecture & Serverless

Designing highly scalable event-driven architectures on AWS and GCP. Lambda, SQS/SNS, Kubernetes — systems built to handle the load.

AWS LambdaSNS / SQSGCPKubernetes

Fullstack Development

End-to-end TypeScript web applications, from React frontend to Node.js backend, with a strong focus on quality and maintainability.

TypeScriptReactNode.jsPostgreSQL

SaaS & Complex Products

From idea to production: multi-tenant SaaS products, third-party API integrations, payment systems, CI/CD pipelines.

SaaSStripeOpenAICI/CD

AI & Automation

LLM integration (OpenAI, Claude, Mistral), RAG, autonomous agents and AI workflows. From proof of concept to large-scale production.

LLMRAGAI AgentsOpenAI

Tech Lead & CTO

Technical team leadership, code standards definition, code reviews, and mentoring. I take ownership of your project's technical vision.

ManagementArchitectureCode review

Technical Audit & Consulting

Code and architecture audits, bottleneck identification, actionable recommendations. I notably conducted the technical audit of a startup as part of its acquisition.

AuditPerformanceConsulting

Matthieu Guigon
15+ years building products that last

Matthieu Guigon

Trained at École 42, I started in Parisian startups before heading to Silicon Valley — an internship won through a hackathon at Milestone Project in San Francisco.

Since then, I've grown from developer to Tech Lead, including a stint as interim CTO at PathMotion during its acquisition.

Freelance since March 2023, I'm also CTO of Flashpricer, an AI-powered e-commerce repricing SaaS platform that I architected and built from scratch.

I love complex problems, architectures that withstand scale, and teams that ship.

Based in Paris, I work in French and English, remotely or on-site depending on your needs.

2023 →

Freelance + CTO Flashpricer

koa-dev / Flashpricer · New York

AWS serverless architecture, AI repricing SaaS platform, managing a team of 4 developers.

2022

Lead Software Engineer

Casap · Paris

Node.js backend, AWS Lambda/SQS/DynamoDB integration, 70% test coverage.

2019

Senior Software Developer

PathMotion · Paris

Monolith → microservices migration, GCP, Kubernetes, technical audit during acquisition.

2018

Backend Developer

Phenix Technologies · Levallois

Backend rebuild, technology benchmarks (Node, PHP, Go, Java).

2015

Lead Technical Architect

Acolad Group · Paris

BFF architecture, PHP microservices, RabbitMQ, internal tool for thousands of employees.

2014

Intern Software Engineer

Milestone Project · San Francisco

Internship won through hackathon — React frontend, infinite scroll, memory optimization.

2012

Freelance + Software Developer

Webgraffy / Premshosting · Pontoise

Custom PHP showcase websites, web hosting infrastructure management and server administration for SMBs and freelancers.

Estimate your
project budget

Mission type
Estimated duration
Engagement
Rate estimate
700820
per day (excl. VAT)

Indicative estimate based on mission type, duration and engagement. The final rate is adjusted after discussing your project.

Refine with me

Let's talk about your next project

Have an ambitious project, an architecture to rethink, or need an experienced tech lead? I'm available for new freelance missions.

Location
Paris & Île-de-France · Full Remote

The tools
in my arsenal

Frontend

Backend

Cloud & Infra

Data & AI