Full-stack Engineer (Agentic AI)

Evaneos; Paris; Hybride; EUR 75 000 - 84 000; Plein temps

Avantages offerts par ce poste

HQ in Paris

Up to 3 days remote per week in Paris

Remote days abroad occasionally

Travel budget

Wellpass

25 days leave + 14 RTT

Choice of PC/MacBook Pro

Résumé du poste

Evaneos is hiring an AI Product Engineer to ship AI-native travel experiences powered by agentic architectures. You will design, build, and operate AI products in production, from problem framing to live monitoring, delivering traveler-facing experiences that improve conversion, experience, and cost.

Based in Paris, the Pathfinder team offers ownership and direct exposure to leadership. The role combines full-stack responsibilities with AI system design, observability, and cost management, in a

Qualifications

• At least 5 years of software development experience.
• Built and deployed AI agents in production with real users.
• Set up or contributed to LLM evaluation pipelines (offline and/or online).
• Hands‑on experience with observability for LLM systems (tracing/monitoring).

Responsabilités

• Design agent architectures: runtime, tool systems, orchestration, middleware, state management, RAG.
• Own context engineering to steer models and manage costs.
• Build evaluation pipelines and observability to catch issues before users see them.
• Own the economics: balance quality, speed, and cost in live products.
• Maintain production readiness: handle model migrations and tool call errors.
• Own the infra and deployment pipeline end-to-end.

Connaissances

Software development

AI agents in production

LLM evaluation pipelines

LLM observability

Outils

Langfuse

Langsmith

Claude/Claude SDK

Langchain DeepAgents

Description du poste

At Evaneos, our mission is simple: to help travelers experience trips that are more local, more responsible, and more human, all around the world. Within the Innovation Department, the Pathfinder team is reinventing how travelers design their tailor‑made trips, with AI as the central lever of the experience.

We are hiring an AI Product Engineer to ship AI-native travel experiences used by real travelers in production. You’ll design, build, and operate AI products powered by agentic architectures, working end-to-end from problem framing to live monitoring, always in service of real user and business needs.

Your impact: you’ll build traveler-facing AI products that move metrics on conversion, experience, and cost. Two are already live and serving traffic: an AI trip designer that helps travelers explore and customize itineraries and a conversational experience that turns their intent into a structured travel project local agencies can act on. Real products, not internal tools.

The Innovation Department

Within the Innovation Department, AI runs on two complementary fronts:

• Pathfinder: we design and build AI-native products to unlock new growth opportunities and keep Evaneos at the forefront of its market.
• AI Company: we solve real team problems to improve internal efficiency, accelerate execution, and build a practical AI-native culture.

You’ll join the Pathfinder team. It’s a small, focused team:

• Lou Anfriani (Product Designer),

The team reports to Romain Quilliot (Head of Innovation), who leads strategy, operations, and execution. By design, the team member owns its direction and proposes initiatives, with direct exposure to C-level leadership on product and business strategy.

Our stack, at a glance

• Languages: Python, TypeScript
• AI/LLM: LiteLLM Gateway, Langfuse, Langsmith, multi-provider (Anthropic, OpenAI, Gemini, Mistral), Langchain DeepAgents, Claude Agent SDK

Your role as a Full-stack Engineer (AI)

• Design agent architectures: runtime, tool systems, orchestration patterns, middleware, state management, RAG. Choose the right pattern for the right problem!
• Own context engineering: shape what the models see and find ways to better steer the model and system, raising quality while controlling cost.
• Make quality measurable: build evaluation pipelines (offline benchmarks plus online metrics) and observability to catch hallucinations, drift, and regressions before users do.
• Own the economic viability: once something is live, find the right balance of quality, speed, and cost.
• Keep it running: debug production issues on non-deterministic systems, handle model migrations when providers change their APIs, and deal with structured output failures and tool call errors.
• Own the infra: You build it, you ship it. Keep the dev environment fast and the deployment pipeline reliable.
• Own problems end‑to‑end: from framing to resolution, in collaboration with product, design, and business stakeholders.

Be a bridge between tech and product

• Take an active part in product direction, grounded in real user and business stakes.
• Translate technical constraints into product options, and explain the paradigm shifts AI brings.
• Proactively communicate on progress, decisions, and blockers: position yourself as an enabler for the team.

Grow our internal AI community

• Co‑lead the AI Champions Tech program, leveling up Product & Tech across Evaneos on AI practices and knowledge.
• Share your learnings with the Innovation team and wider tech community.
• Run workshops and talks that demystify what matters in the agentic era.

You build the product, not the platform. Focus on shipping AI experiences directly to travelers: real users, real conversion, real business impact.

Full ownership in a team that fits in one room. No ticket queues, no handoffs between ML and product teams. You frame problems with the PM, design solutions with the designer, build and ship them yourself, then watch the traces to know if it works. The loop is tight and you own all of it.

AI at the core of a 17‑year‑old profitable marketplace. This isn’t a startup burning cash on an AI bet. It’s an established travel company with real revenue, real users across 160+ destinations in over 5 markets, and a strategic conviction that AI will reshape its core experience. Startup autonomy with business‑model gravity.

What’s in it for you?

• La Voyagerie: our lively HQ in the 9th arrondissement of Paris
• Based in Paris? Up to 3 days of remote work per week.
• Fully remote? Up to 2 consecutive days on‑site per month when the whole team comes together in Paris.
• Travel budget through the CSE to experience Evaneos trips.
• Remote work from abroad several times a year.
• 25 paid leave days + 14 RTT days.
• Choice of PC or MacBook Pro.
• Wellpass (yoga, meditation, sports partially covered).
• Cultural lunches, seminars, afterworks, and regular team moments.

Salary range: €75–84K gross annually, based on experience.

What we’re looking for

You may be a great fit for this position if:

• You have at least 5 years of software development experience and are comfortable with APIs and data stores.
• You’ve built and deployed AI agents in production with real users: not just PoCs or hackathon projects.
• You’ve set up or contributed to LLM evaluation pipelines (offline benchmarks and/or online metrics) and have designed guardrails.
• You have hands‑on experience with observability for LLM systems: tracing, monitoring, diagnosing regressions from traces (Langfuse, LangSmith, or equivalent).

Mindset & ways of working

• Curious and passionate about AI: you keep up with the state of the art, test things to understand them, and apply what you learn to what you build.
• Full‑stack at heart: in a small team, you’re happy to touch front, back, and infra. No “That’s not my job.”
• Strong ownership: you spot problems, propose solutions, and move forward while keeping everyone in the loop. You finish what you start.
• Product appetite: you want to understand users, conversion, and the business. Engineering is a means to an end: crafting meaningful experiences and solving real customer problems.
• Team player: You like pairing, sharing knowledge, communicating clearly, and pulling in the same direction.
• Fluent in professional English.

You’ll thrive here if:

• You want to build and ship AI products to real users, not do pure ML research.
• You care about the product outcome, not just the technical pipeline.
• You’re comfortable working daily alongside product, design, and business stakeholders.

Recruitment process

We are committed to creating an environment where everyone feels respected and included. We strive to provide equal employment opportunities, regardless of gender, sexual orientation, background, disability, or any other characteristic that makes you who you are. Our goal is simple: to ensure that everyone can thrive, feel safe, and be treated with respect.

In French and/or English:

• HR call with our Talent Acquisition Manager (Greismar): Initial chat to get to know you, learn about your work experience, and how they connect to the role 30 - 45 minutes
• Take-home assignment (with your favorite coding agents): build an agent integrated into a travel product. We’ll share the brief, evaluation criteria, and expected deliverables upfront.