senior dev fullstack

About

Selego is strengthening its team on a strategic account undergoing a transition to an educational SaaS platform. We are looking for a versatile senior fullstack developer with a strong AI aptitude, capable of working across the entire stack (React front, Ruby on Rails back, HubSpot and third-party integrations) to support an ambitious AI roadmap (tutor assistants, process automations) and the migration of business integrations.

You will work in tandem with the account's operational lead, acting as a client partner, and will directly contribute to the technical seniority of the Selego team on the project.

Stack & Missions

Stack: React (front), Ruby on Rails (back), HubSpot integrations, AI components.

Main Missions

• Contribute to AI projects (tutor assistant, process automation) — from prototype to deployment.
• Port HubSpot and third-party integrations on the Rails back-end.
• Strengthen the team's technical seniority on the account: reviews, architecture choices, mentoring junior/mid-level developers.
• Contribute to the Platform Brief on AI and integrations.

Profile Sought

Experience

• 5+ years in modern fullstack development.
• Significant experience on projects integrating AI components (LLM, OpenAI/Anthropic API, RAG, agents) — from prototype to production-ready.
• At least one experience with Ruby on Rails in a production environment.
• Experience with HubSpot integrations or similar CRM/marketing platforms.

Technical Skills

• React, Ruby on Rails, Node if possible.
• REST APIs, webhooks, third-party integrations.
• AI components: prompt engineering, LLM integration, agentic workflows.

Soft Skills

• Autonomy, client partner mindset.
• Ability to work in tandem with an operational lead.
• Clear communication in client meetings.

Job Framework

• Format: Selego CDI or long-term freelance (to be decided together).
• Assignment: 1.0 FTE on the account.
• Location: Paris — 3 days/week at the Selego office, 1 day/week onsite at the client's, 1 day/week optional remote.
• Desired Start Date: Q3 2026.
• Management: Reporting to Deborah Jace.

Culture & Values

Selego upholds three core values that we expect from the recruited profile:

• Performance — High standards for deliverables, rigorous execution, focus on client impact.
• Teamwork — Ability to work in a team, share knowledge, support more junior profiles.
• Curiosity — Aptitude for emerging topics (especially AI), desire for continuous learning.

Recruitment Process

• Sourcing and initial filter — Nour.
• Technical interview — Deborah + account technical lead (video call).
• Account and commercial framework interview — Yann.
• Reference checks.