Backend Developer – Versatile - node.js

Looking for: A versatile backend developer to join me on a freelance basis
Location: Remote (Paris / Massy area preferred for occasional sync)
Mission type: Freelance, flexible (starting with a training period, potential for ongoing collaboration)
Start: ASAP

About me

I'm an independent AI consultant and implementer, specialized in the finance sector — private equity, M&A, audit, and corporate finance (CFOs/DAFs). Alongside client-facing AI training and consulting, I build my own internal SaaS products and tools (Next.js-based platforms, automation pipelines, CRM systems) to support my work and offering.

I'm looking for a versatile backend developer to support the build, testing, and maintenance of these tools.

What you'll work on


Building and maintaining backend services and APIs (Node.js / Next.js API routes)
Writing and running tests to catch bugs before they reach production
Working across a small stack of internal tools (SaaS products, automation pipelines, CRM integrations)
Reviewing, debugging, and improving existing code
Collaborating via GitHub (PRs, code review, clean commit history)
Occasionally integrating third-party APIs (enrichment tools, telephony, AI/LLM APIs, etc.)


What we're looking for


Solid backend fundamentals — Node.js required; familiarity with Next.js/React a plus
Comfortable with API design and integration (REST, third-party APIs)
Testing mindset — you write tests, not just code, and you catch edge cases
Confident with Git/GitHub workflows (branches, PRs, code review)
Detail-oriented — this is non-negotiable. We need someone who double-checks their work
Autonomous enough to pick up a scoped task and run with it, but communicates clearly when something's unclear
Nice to have: experience with Firebase, background job queues (BullMQ or similar), or deployment on Railway/Vercel/Azure


What this is NOT
Not a massive greenfield architecture project — most work is on existing, scoped codebases
it will become a full time position etc