Senior Fullstack Engineer

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

Today, up to 25% of healthcare spending is lost to manual, repetitive administrative tasks. Legacy software hasn't helped: it has made work slower, more complex and more frustrating for care teams.

We believe AI agents can change this. Our technology combines large language models with system-level automation to do real work inside existing hospital tools. No integration, no disruption.

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

We launched in 2024 and already have 800+ customers and a team of 30+ people. We are backed by top-tier investors (Index Ventures, Y Combinator, Hexa, Frst, Kima Ventures, Better Angle and the CEO of Mistral AI), and this is just the beginning.

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

Context

We're at a turning point. We're hiring a Senior Fullstack Engineer to help us scale: not just to write code, but to shape our architecture, make key product decisions and define our engineering culture.

You will own the entire tech stack, from backend services to user interfaces, and help us deploy reliable AI agents in hospitals.

What you'll do

• Build production systems, not prototypes: robust, secure and HDS-compliant, designed to run in demanding hospital environments.
• Ship and evolve LLM-based agents that automate complex workflows end to end.
• Make the right architecture decisions with the CTO, balancing speed and long-term scalability.
• Build interfaces that doctors and administrative staff actually want to use, by understanding their pain points rather than closing tickets.
• Lay the engineering foundations: CI/CD, observability, internal tooling, code quality standards.

In your first months, you will have owned the full lifecycle of major features (from spec to production monitoring), designed a modular backend architecture that handles multiple customers with complex business rules, deployed AI agents in production with a high level of reliability, built HDS-compliant data pipelines between hospital systems and our stack, and improved the team's velocity through better tooling.

Who you are

• You have at least 5 years of experience in full-stack development.
• You graduated from a top engineering school.
• You are proficient in Node.js and TypeScript (NestJS, Express, Prisma, Postgres) as well as React (TanStack, Tailwind).
• You have already worked with LLMs and AI agents, on personal or professional projects (LangChain, Hugging Face).
• You are comfortable with infrastructure and deployment (AWS, Docker, Terraform, Kubernetes, GitHub Actions).
• Product matters as much as code to you: you challenge what doesn't make sense and propose solutions.
• You are autonomous and pragmatic: at this stage, a shipped solution beats a perfect one.

Our values

• Play to Win: we're not here to just take part, deliver something "good enough" or simply enjoy the startup ride. We want to win. That means caring about results, moving fast and bringing the right intensity when it matters.
• High Trust, High Standards: trust is our starting point. If you join us, it's because we believe you can own your scope and make good decisions. We don't want a company built on approvals, control and micromanagement. But trust comes with accountability: the more freedom you have, the higher the bar.
• Low Ego, Hands-On: at Parallel, no one is above the work. No title, seniority or past success exempts anyone from getting involved in the actual work. Leading means taking responsibility, not distancing yourself from execution.
• Don't Take Yourself Too Seriously: we take our mission very seriously, not ourselves. Building a company is intense. We want Parallel to remain a place where people enjoy spending time together, laughing, celebrating and giving energy to others. High standards and a good atmosphere aren't opposites: we want both.

Hiring process

1. Call with the Hiring team (30 min)
2. Call with Chris, CTO (30 min)
3. Product case study and interviews with Chris and Paul, the founders, at our office in Paris 2nd (2 hours)
4. Reference checks

Why join us?

• Real autonomy: we don't hand you a backlog. You co-build the architecture and set the engineering culture.
• A different technical approach: agents that work on existing systems without heavy integration, a real competitive advantage that you build.
• Real traction: seed and Series A ($20M with Index Ventures) closed in less than a year, 800+ customers and a team of 30+ people.
• Strong investors and founders: Index Ventures, Y Combinator, Hexa, Frst, Kima Ventures, Better Angle and the CEO of Mistral AI; founders who come from Meta, McKinsey and Hublo.
• A complete package: competitive salary and equity (BSPCE), Alan health insurance, Swile meal vouchers, Apple equipment, 50% of public transport covered.
• A close-knit team: a team event every month and two offsites a year.
• Our office: Paris 2nd arrondissement.
• Flexibility: on average one day of remote work per week and one week of remote work per year.

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.