Freelancer profile translated to English.

Description

Stéphane Klein, artisan developer with over 20 years of experience, based in Montrouge, south of Paris.

From 2019 to 2023, I held the position of CTO at a Parisian startup, which I joined just after its initial funding. With my colleagues, we expanded the tech team from 1 to 16 people over two successive funding rounds of approximately 5 and then 20 million euros.

September 2023 to June 2024, I worked on the development of a "knowledge management" type application that I launched with three co-founders.

I started Freelance missions in July 2024.

I am open to Individual Contributor or management missions, within very small structures or ETIs.

Areas of Expertise

Frontend Development: JavaScript (front), ReactJS, Svelte, SvelteKit, advanced HTML/CSS, TailwindCSS, Yjs
Backend Development: Go, Python, JavaScript (back), GraphQL, REST, gRPC, Playwright, basic Bash script writing, Singer (ETL)
Database: SQL, advanced PostgreSQL, PL/pgSQL, SQLite, Redis, Clickhouse, Neo4j (Cypher), Metabase
DevOps: Docker, Vagrant, Postfix, Nginx, Ansible, Terraform, Grafana, Prometheus, Loki, Kubernetes, Debian/Ubuntu/RedHat, Baremetal, AWS, Scaleway, OVH, Vector (data pipeline)
Software Engineering: Git, Scrum, TDD, Lean, GitOps

Industry field of expertise

Languages

English
Conversational
French
Native or bilingual

Workplace preferences

Can work on-site

Paris (up to 50km), Paris (up to 30km)

Value Props
Co-founder, CTO
SOFTWARE PUBLISHING
September 2023 - June 2024 (10 months)
Paris, France
I worked for 1 year, in "solo dev" mode on a "knowledge management" type application that we launched with three co-founders.

The objective of this solution is to allow companies to present their product through all types of media - web page, presentation, product sheets... -, always up-to-date, which were created and updated via a webapp that dynamically organizes and presents all marketing data or in other words, "the value proposition".
Svelte SvelteKit Node.js PostgreSQL TailwindCSS codemirror Docker docker-compose Scaleway Terraform
Spacefill
CTO
TECH
April 2019 - June 2023 (4 years and 2 months)
Paris, France
I joined Spacefill just after its initial funding. With my colleagues, we expanded the tech team from 1 to 16 people during two successive funding rounds of approximately 5 and then 20 million euros.

As CTO, I was responsible for technical choices, recruitment, and developer management, all in close collaboration with the CPO — co-founder.

I started by developing a warehouse storage marketplace, then an OMS (Order Management System) type web application, and a public web API.

This public web API allowed communication with applications in the logistics universe, such as WMS, OMS, TMS, ERP.

I worked on the implementation and deployment of numerous "EDI" integrations, specifically programs (worker type) for transferring information from one system to another — reading data via Web API or via files exposed by the FTP protocol, then transforming this data, and finally writing this data to a Web API or again into files via the FTP protocol.
JavaScript Git PostgreSQL SQL PL/pgSQL Docker docker-compose React.js TailwindCSS Node.js Amazon Web Services GitlabCI Python Metabase Grafana Prometheus Ansible Terraform postgraphile
Scaleway
DevOps, Lead Developer
TELECOMMUNICATIONS
January 2018 - Today (8 years and 5 months)
Paris, France
Language, libraries, and tools:

Ubuntu, Golang (grpc, genproto, sqlx, cobra/viper, logrus...), gRPC and Protobuf, Vagrant, Docker, Ansible, GitLab CI/CD, Some Bash for scripting, Packer, iPXE, TFTP (Hooktftp), DHCP Server, PostgreSQL, Migrate, Minio, Sentry...

Procedures and organization methods:

- Follow GitFlow workflow
- Use of Merge Requests and code review for each patch
- Documentation as projects evolve in Markdown format
- All actions start with an issue
- Creation and use of Mocks to easily test the integration of multiple components
GO grpc protobuf Vagrant Docker Ansible