Full-Stack Engineer - Internship

Company: HyLight (YC S23)

Location: Base 217, Brétigny-sur-Orge - accessible via RER C

Team: Platform

Duration: 4 - 6 month internship, starting in 2026

Job Summary

HyLight designs and operates next-generation airships for aerial inspections. Our HyLighters fly long-range, low-emission missions to inspect energy infrastructure - detecting methane leaks on pipelines and defects on power lines.

As we scale toward industrial volume, the bottleneck is no longer just flying - it's everything around the flight. We're looking for a Full-Stack Engineering Intern to join the Platform Team and help us build the internal tools, ground station software, and cross-team automations that let HyLight operate at scale.

The Platform Team is making the bridges between each team to build reliable, unified solutions meant to industrialize our processes and keep the team focused on what matters the most. From sales automations to operational deployment - we build the internal engine of the company.

Missions

Internal Tools

• Ship internal applications. Build the apps the team uses every day - for operations, regulatory, sales, and tech. Think mission planning, fleet & inventory tracking, post-flight review, regulatory dashboards, CRM-adjacent tooling, ...

• Understand the business and model it. Spend time with the teams you build for, learn how the company actually operates, and translate that into clean data models and the right abstractions in code.

• Automate manual workflows. Identify the repetitive, error-prone steps that slow the company down - regulation & compliance paperwork, hand-offs between teams, status updates -and replace them with software.

• Integrate the systems. Connect the tools the team already uses (Notion, Slack, GitHub, OnShape, etc.) so data flows automatically and a single source of truth exists across the company.

• Hard, domain-specific problems. Help operations turn a vast set of criteria - weather, airspace, regulation, fleet availability, mission objectives - into a concrete flight schedule.

• Contribute to the ground station - telemetry dashboards, sensor feeds, and pilot-facing tools - working hand-in-hand with the embedded team on clean contracts between the aircraft and the ground.

Engineering

• Contribute to the APIs and services supporting frontend applications and integrations.

• Participate in creating automations and implementing AI-powered tools.

• Learn and apply good engineering practices around testing, scalability, and code quality.

• Collaborate closely with the Head of Platform and other engineers.

Profile Sought

Education and experience

• Currently pursuing a Bachelor's or Master's degree in Computer Science, Software Engineering, or equivalent practical experience.

• Looking for a 4-6 month internship starting in 2026.

• Interest in building tools that people inside the company will use every day.

Technical skills

• Frontend: comfortable with React / Next.js, TypeScript, TailwindCSS, or similar.

• Backend: comfortable with Node.js frameworks (NestJS, Express) or Python (FastAPI), REST, relational databases (PostgreSQL).

• Comfortable with Git, Docker, AWS, Railway, and CI/CD pipelines , and modern web app fundamentals.

• Comfortable leveraging AI tools to ship faster (Cursor, Claude Code, Copilot, …).

• Bonus: familiarity with GIS tools / geospatial stacks (MapLibre, Mapbox GL, Leaflet, PostGIS, GeoJSON, vector/raster tiling), C/C++.

Soft skills

• Curious. You ask why things are built the way they are, and you go figure it out when no one answers.

• Open-minded. You hold opinions strongly, but you change them when shown something better. You assume good intent.

• Genuinely autonomous. Hand you a fuzzy problem, you come back with a v1 and the right follow-up questions - not waiting to be told the next step.

• Passionate. You genuinely care about what you do - you build, you read, you tinker, you have opinions. Whether it's code, climate, aerospace, or anything else, you bring real interest to the table.

• At home in a high-pace environment. Priorities shift, decisions are made fast, reality wins over plans. You see that as fuel, not friction.

Languages

• English required (internal communication and documentation).

• French is a plus.

What We Offer

• Hands-on internship with real responsibility and direct impact from day one.

• Mentorship from the CTO, the Head of Platform, and engineers across the stack.

• Tools you build will be used by pilots, operators and engineers every single week.

• Get to participate in flight tests on the airbase - see the systems you build run on a real aircraft.

• Exposure to a modern stack and a genuine fast-paced startup environment.

• Potential opportunity to continue full-time after the internship.

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

• Bike provided for commuting.

• Free lunch.

• Bi-annual offsite trips with the whole team.

• Excellent work environment: international team, team events, beautiful offices on a former airbase - flights happening right outside the window.

Why You Should Join

Founder Mentality: We value ownership and people who enjoy building, solving problems, and making things happen quickly.

Ground Floor Opportunity: You'll help shape the internal platform that lets HyLight scale to inspecting millions of kilometers of energy infrastructure per year.

Impact & Learning: Work side-by-side with experts in embedded systems, aerospace, and data platforms - where your impact matters from day one.

Interview Process

• Introductory phone call (30 min)

• Take home work

• Technical discussion

• On-site meeting with the team

Location

Office: Base 217, Brétigny-sur-Orge , accessible via RER C. Lab and warehouse access.