Sébastien Schaeffler

PRINCIPAL SOFTWARE ENGINEER

Team lead with 23 years of experience delivering high-performance, scalable systems across full-stack development. Proven expertise in solution architecture, cloud-native platforms, creative frontend and building high-performing distributed teams.

About

I'm a team lead with 23 years of experience in software engineering, specializing in high-performance, scalable backend and frontend services.
My expertise spans solution architecture, cloud-native platforms, and successfully delivering challenging projects while leading distributed teams.

Frontend & Backend: React, TypeScript, TailwindCSS, Next.js, Node.js, GoLang, Python

Cloud & Infrastructure: AWS, GCP, Azure, Kubernetes, Terraform

Currently serving as Solution Architect and Principal Engineer at Deutsche Börse Group, I design secure and performant cloud native platforms. I collaborate with business and IT stakeholders to define requirements, establish technology stacks, and drive API strategies while implementing customer-facing applications.

Based in Luxembourg with fluency in French and English, I'm available for remote and hybrid opportunities.

Experience

Nov 2024 — Present

Solution Architect & Principal Engineer

Deutsche Börse - Group Marketplace
Kirchberg, Luxembourg

Designing secure and performant customer-facing applications. Collaborating with Business and IT stakeholders to define requirements and technical specifications. Defining technology stack, building abstractions, preparing GCP cloud infrastructure, and integrating with group SSO, SAML, OAuth2, and OIDC. Establishing the new design system for Deutsche Börse customer-facing applications in React. Leveraging AI tools for customer support, chatbots and monitoring.

ReactTypeScriptGCPKubernetesOAuth2OIDCSAMLAI/ML
Visit DBG Marketplace
Aug 2024 — Oct 2024

Principal Frontend Engineer

Nova React Kit

Designed and developed Nova React Kit, a comprehensive design system and component library for building consistent and scalable user interfaces in React applications. Established design principles, component architecture, and theming capabilities to ensure a cohesive user experience across applications.

ReactTypeScriptTailwind CSSDesign SystemsComponent Libraries
Visit Nova React Kit - Design system
Nov 2023 — Nov 2024

Team Lead & Solution Architect

Clearstream Fund Services - CFS Banking Portal
Kirchberg, Luxembourg

Application owner deputy of Clearstream Fund Banking Portal and lead of three squads, including offshore teams in India. Established solution architecture of customer-facing applications, ensuring security (SSO, OAuth2, OIDC) and performance. Led diverse and remote squads, integrating and delivering all customer-facing applications for initial release and two subsequent releases while migrating clients to the new platform. Drove UI/UX initiative and implemented new design system for Clearstream.

ReactTypeScriptOAuth2OIDCTeam LeadershipAgileDesign Systems
2017 — Nov 2023

Solution Architect & Frontend Lead

Deutsche Börse - Digital Business Platform
Kirchberg, Luxembourg

Co-founded the Digital Business Platform, architecting and implementing a solution for the Group's foray into the API economy. Built a modern developer portal and cloud-native API Gateway featuring first-class authentication services (2-way SSL, OAuth2, OpenID Connect), flexible policies (rate limiting), and reporting capabilities.

ReactTypeScriptNext.jsGoLangNode.jsPythonAWSKubernetesTerraformDocker
Visit DBG Developer Portal
2005 — 2017

Senior Software Engineer - Frontend Tech Lead

Clearstream Services - Connectivity
Kirchberg, Luxembourg

Led frontend development for Clearstream Xact Portal, the connectivity channel for Collateral Management and Settlement services for internal operations, customers and partners. Developed Clearstream Xact Mobile application as an extension of Xact Portal.

JavaScriptNode.jsiOS (Swift)Android (Java)JavaJBoss AS
Visit Clearstream Xact
2002 — 2005

Software Engineer

Société Européenne des Satellites
Betzdorf, Luxembourg

Full stack frontend, backend and infrastructure development on premise. Worked with proprietary technologies in C++.

C++Full Stack Development

Projects

Coalab - Where creators connect and collaborate with one another and digital marketers

A collaborative platform designed to connect creators and digital marketers, facilitating seamless collaboration on projects. Features user profiles, project management tools, and communication channels to enhance teamwork and productivity.

ReactTypeScriptNext.jsTailwind CSSPostgreSQLSupabase

Chain Reaction - Word Puzzle

An engaging word puzzle game where players create chains of words by changing one letter at a time. Built with modern web technologies for a smooth, responsive gaming experience.

ReactTypeScriptNext.jsTailwind CSS

Coffee Shop - E-commerce Website

A fully responsive e-commerce website for a coffee shop, featuring product browsing, shopping cart functionality, and a modern, clean design optimized for all devices.

ReactJavaScriptCSS3Responsive Design

Eat Fresh - Website Template

A responsive website template built in React for food and restaurant businesses. Features modern design patterns, smooth animations, and mobile-first approach.

ReactJavaScriptCSS3Responsive Design

Contact

Let's build something together. I'm open to discussing new projects, creative ideas, or opportunities to collaborate.