Senior Full-Stack Engineer — 9+ years building production systems
I build billing and payment platforms, complex third-party integrations, and SaaS products for companies across France, Switzerland, Germany, the US, and Morocco — and, more recently, modern AI-powered products.
Currently: contract & billing platform for a French energy company. React, Next.js, Node.js, PostgreSQL, Docker. Fluent in French and English.
Open to full-time roles and long-term contracts — available immediately.
Selected Work
Production systems I've built for clients across Europe and the US — plus one independent AI project.
Contract & billing platform for a French energy company
Contract creation, billing, and reconciliation were split across manual steps and disconnected external systems — energy delivery data arrived as XML files that had to be validated before it could be turned into an accurate invoice.
What I builtBuilt the core contract creation flows and customer-facing dashboards, then built the billing pipeline end to end: ingesting and validating XML delivery data, running the business calculations that turn usage data into charges, and generating invoices. Integrated Haulogy for energy contract data, Enedis for electricity delivery point data, Pennylane for accounting synchronization, and DocuSign for contract signature — with a GoCardless payment integration in progress. Deployed and operated the platform in production.
IntegrationsGerman Pharmacy Platform
Built the complete customer-facing frontend for a production pharmacy platform using Next.js.
Interlincx Media
Built form builders and a drag-and-drop template builder for content editors and analysts producing monetizable articles, including offer and template systems for editorial tooling, and worked directly with the engineering team to extend the Netlify CMS.
Mobiletic
Built a large-scale e-learning platform used by multiple companies, with REST APIs, SSO authentication, and real-time features via WebSockets. Worked on database query optimization, caching, background queues, and transactional email.
Sagatech
Built payment gateway and barcode integrations on a SQL Server backend, then led the migration and rebuild toward a cloud architecture using Laravel, React, and MySQL.
Independent AI Project
Coffee AI
A live RAG application exploring semantic search, vector retrieval, and LLM-powered recommendations — coffee shop data is embedded with OpenAI and stored in PostgreSQL via pgvector, each query is matched against that index by semantic similarity, and the retrieved results are passed to Anthropic's Claude to generate the response.
Core Technologies
Experiences
Senior React & Next.js Engineer (Freelance)
European Energy-Tech Company
Remote
2024–2026
Contract creation flows, customer dashboards, and billing automation for a French energy company, integrating Haulogy, Enedis, and Pennylane. Full case study above.
React Developer
Interlincx
Los Angeles, CA
2021–2024
Built form builders and client templates for content editors and analysts producing monetizable articles, and worked directly with the engineering team to extend the Netlify CMS.
Full Stack Developer
Mobiletic
Geneva, Switzerland
2020–2022
Built a large-scale e-learning platform with SSO authentication and real-time features via web sockets, using Laravel, React, and Angular.
Full Stack Developer
Sagatech
Meknes, Morocco
2019–2020
Built payment gateway and barcode scanner integrations on a SQL Server backend, then rebuilt the product as a cloud version using Laravel, React/Node, and MySQL.
Full Stack Developer
IN4
Meknes, Morocco
2018–2019
Built multiple e-commerce websites, each with client-specific requirements, using Laravel.
Hiring for a senior engineer who ships production systems?
Billing and payment platforms, complex integrations, SaaS products, and AI-powered systems. Open to full-time positions and long-term contracts — let's talk about what your team is building.
Email: omar.lekouch@gmail.com