Senior Fullstack Engineer at Parallel – Paris | Jobyssey

At Parallel, we build AI agents to help healthcare facilities automate their administrative processes and unlock additional revenue, starting with medical coding.

Today, up to 25% of healthcare spending is lost in manual, repetitive administrative work. Legacy software hasn’t helped, it’s made things slower, more complex, and more frustrating for care teams.

We believe AI agents can change that. Our technology combines Large Language Models with system-level automation to handle real work inside existing hospital tools. No integrations, no disruption.

Our first agent automates coding workflows and frees up time for medical staff to focus on patients.

We launched in 2024, are backed by top investors (Index, Frst, Y Combinator, Hexa, Kima Ventures, Better Angle), and we’re just getting started.

The future of healthcare isn’t just digital — it’s automated. Come help us build it !

Context

We're at a pivotal moment. We've closed a $20M Series A with Index Ventures, we're deployed in 40+ hospitals, and we're scaling fast. The company was built by Paul Lafforgue (Polytechnique, ex-Meta, ex-McKinsey) and Chris Rydahl, whose previous company Hublo became Europe's largest healthcare staffing platform. We're 15 people, based in Paris.

We're now hiring a Senior Full-Stack Engineer to help us scale — not just to write code, but to shape our architecture, make key product decisions, and define our engineering culture.

Your mission

Own the full technical stack — from core backend services to user-facing interfaces — and help deploy reliable AI agents in hospitals.

Concretely, you will:

Build production-grade systems, not prototypes — robust, secure, and HDS-compliant, designed to run in demanding hospital environments
Ship and iterate on LLM-powered agents that automate complex end-to-end workflows
Work alongside the CTO to make the right architecture decisions, balancing speed and long-term scalability
Build interfaces that doctors and administrative operators actually want to use — understanding their pain points, not just closing tickets
Lay the engineering foundations: CI/CD, observability, internal tooling, code quality standards

Outcomes

In your first months, we expect you to:

Own the full lifecycle of major features — from spec to production monitoring
Design a modular backend architecture that supports multiple clients with complex, custom business rules
Deploy AI agents in production with a high reliability bar
Build and maintain solid data pipelines between hospital systems and our stack, HDS-compliant
Improve team velocity through better tooling, CI/CD, and observability

This job is for you if:

You have 5+ years of full-stack experience
You're strong in Node.js & TypeScript (NestJS, Express, Prisma, Postgres) and React (TanStack, Tailwind)
You've played with LLMs and AI agents — whether on side projects or professionally (LangChain, Hugging Face)
You're comfortable with infrastructure and deployment (AWS, Docker, Terraform, Kubernetes, GitHub Actions)
You care about the product, not just the code — you push back when something doesn't make sense, and you propose solutions proactively
You're autonomous and pragmatic — done beats perfect, especially at this stage
You're French-speaking
You graduated from a top engineering school

Hiring process

Quick call with Chris, our CTO
Case study at our Paris office
Meeting with Paul, our CEO
Drinks with the team

Why join us?

Real traction. Seed and Series A closed in under a year, with Index Ventures on the cap table. This isn't a maybe — it's a company that's moving.
A problem worth solving. Cutting hospital admin directly gives time back to care teams. The impact is tangible.
A genuinely different technical approach. Agents that work on top of existing systems without heavy integration is a real competitive edge — and you'll be the one building it.
A team that has done it before. The founders have built and scaled before (Hublo, Meta, McKinsey). High standards, low ego.
Actual ownership. You won't be handed a backlog. You'll co-build the architecture and set the engineering culture from the ground up.
Competitive salary and equity package, premium health insurance (Alan), Swile meal vouchers, latest Apple equipment, Paris office (Strasbourg Saint-Denis).

We care about who you are, not just what's on your CV.

If you're drawn to what we're building but don't meet every requirement, we still want to hear from you. Studies show that women in particular tend to apply only when they meet 100% of the criteria. If that's you, please don't let that hold you back. We'd love to receive your application.

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