About HyLight

Power lines, gas pipelines and railways are still inspected the way they were 50 years ago: by helicopter. Expensive, noisy, and up to a tonne of CO₂ per flight hour.

We built the alternative. The HyLighter is a 12-metre autonomous airship running on hydrogen. It flies for up to 10 hours, almost silently, and spots a 1 mm defect from 25 metres up.

But the airship is only half the story. Every flight brings back massive amounts of LiDAR, imagery and methane data, and that's where the value is. Our AI turns it into what operators act on: 50+ types of defects detected automatically, and leaks pinpointed across their network.

It's not a prototype. HyLighters already fly missions for France's largest energy and rail operators and have flown over the Palace of Versailles. Backed by Y Combinator, we just raised €13M to go from 4 airships to 15.

Working at HyLight

We design, build and fly every HyLighter, and turn its data into insight, all under one roof on a former airbase. Which means:

• You own it all the way. At a big tech company, you'd own a small piece of one service. Here, you build it, ship it, and see the client act on what it tells them.

• Weeks, not years. Ideas go from whiteboard to production in weeks.

• Responsibility from day one. The founders' average age is 27. Nobody here waits for permission.

We don't care about titles or ticking every box. We care about what you build and the perspective you bring, so if your profile is different, apply anyway.

Job Summary

Every flight produces terabytes of LiDAR, imagery and methane data. Our Platform is where that data becomes something a customer can act on: the heavy processing behind the scenes, and the web app and dashboards our customers use. It is the product they actually see.

Today it serves a handful of airships and a handful of customers. The plan is insights at French national level in 2027, and worldwide in 2028. That is orders of magnitude more data, more customers, and far less tolerance for failures.

As a Software / Cloud / Data Engineer, you will own large parts of that platform, from the processing in the cloud to the interface the customer uses, and make it robust, fast, scalable and cheap. You will decide how it runs, where it runs, and what it costs. We may even bring part of the compute in-house, in our own data center, and you will help decide when and how.

Mission

Within the data team, working closely with the Head of Data and hand in hand with embedded and operations, you will:

Make the platform robust and fast

• Reliable by default. Jobs that finish, recover on their own when something fails, and tell us precisely what went wrong.

• Speed. Cut the time from landing to delivered insight.

• Quality you can trust. Catch missing or corrupted data before a customer does.

• Visibility. See problems early, not when a customer reports them.

Make it scale

• From a few airships to a fleet, from a region to a country, then the world. Design what survives 10x and 100x more data.

• Grow without growing the bill. More data should not simply mean bigger machines.

• Many customers, many use cases. Each new business case runs on the same foundation without turning into a pile of special cases.

Make it cheaper

• Cost per flight hour as a first-class metric. Measure what each step costs, and cut it.

• Cloud and beyond. Decide what stays in the cloud, and what is worth running in our own data center.

Deliver the insight

• Own the web app and dashboards. The place where operators see and use what we detect.

• Stay close to the user. Talk to operators, watch how they use it, and fix what annoys them. The interface is only as good as the pipeline behind it, so you work on both.

Personal Note from Louis (Head of Data)

"The platform is where our flights turn into value, and we're about to ask it to do ten times more, then a hundred times more. I'm looking for someone who loves owning a system end to end: who can design the architecture, ship the feature, debug the incident at night, and then make the cloud bill drop. You'll have a lot of autonomy, and the result will be something customers use across France next year and worldwide the year after."

Profile Sought

We're looking for someone who builds and runs software in production, and who gets energy from making it faster and cheaper. You may be more backend and cloud, or more fullstack. What matters is that you've owned real systems.

• A background in backend, fullstack, data or cloud engineering, running systems in production.

• Comfortable from heavy data processing in the cloud to the interface that exposes it.

• You treat cost and performance as engineering constraints.

• Experience with large data volumes.

• A track record of end-to-end ownership: you've run something in production, been called when it failed, and made it better.

• Familiar with recent LLM techniques (agents, tool use, coding assistants) and how to apply them to real workflows.

• An engineering degree or equivalent practical experience. We care about what you've built, not where you studied.

Show us what you built

We hire people who build things nobody asked them to. A company you started, a product you shipped and kept alive, a side project with real users, open source you contribute to, a system you rescued or rebuilt at work. Send us the link. It matters more than the line on your resume.

Soft Skills

• Fast learner. You don't need to have done exactly this before. You need to pick up whatever the problem calls for, quickly.

• Cost-aware. You treat money and compute time as engineering constraints.

• Reliability-obsessed. You'd rather build a check than hope it works, and you write the runbook so the next person doesn't need you.

• Product-minded. You care what the customer sees, not just that the job ran.

• Autonomous. Hand you a fuzzy problem and you come back with a v1 and the right follow-up questions.

• Languages: English is required. French is a plus.

AI Leverage

We're building HyLight as an AI-native company. That's not a buzzword: it's how we work.

• You use AI tools fluently every day: Claude Code, Cursor, Copilot, or whatever gives you the edge.

• You look for places where AI can replace a workflow entirely, like data QA, incident triage, or reporting.

What We Offer

• Potential to become a shareholder in HyLight.

• Real ownership and direct impact from day one.

• An excellent work environment: an international team and beautiful offices on a former airbase, with flights happening right outside the window.

• Bi-annual offsite trips with the whole team.

• 100% reimbursement of your public transport pass (Navigo), or €800/year for sustainable commuting.

• A bike provided for commuting.

• Free lunch.

• Access to a sauna and gym on-site.

Why You Should Join

• Founder mentality: we value extreme ownership and want people who think like founders: fast decision makers, natural problem solvers, and executors.

• Ground floor opportunity: you'll help shape and grow a revolutionary company with the resources to back it.

• Impact and scale: you'll build the platform that takes us from a handful of customers to national coverage in 2027, and worldwide in 2028.

Interview Process

1. Introductory phone call (20–30 min)

2. Technical case study, followed by a debrief with the Head of Data

3. On-site meeting with the team (3–4h)

4. Reference calls

Location

• Office: Base 217, Brétigny-sur-Orge, accessible via RER C. Remote work is part of how we operate, but regular presence on the base is part of the job.

• Lab and warehouse access.