Senior AI Engineer 🇪🇺

Pennylane is one of the fastest growing Fintechs in France (and soon in Europe!). In 5 years of existence, we've managed to:

• 💻 Make ourselves known as a groundbreaking accounting and financial software for small businesses and their accountants

• 💰 Raise a total of €400 million, including from Sequoia — the famous Silicon Valley fund that invested early in companies like Google, Facebook, Airbnb, Stripe and Paypal

• 👨‍👩‍👧‍👦 Grow from 7 cofounders to 1,000 happy Pennylaners, and earn a place among the greatest companies to work for in France (and remotely), with a 4.6/5 rating on Glassdoor

• 🌍 Build an international environment with more than 25 nationalities and a strong remote-friendly culture, where 30% of employees already work from all parts of Europe

• 🤝 Earn the trust of thousands of customers and accounting firms, with outstanding ratings

• 🚀 Reach more than 1,000,000 small and medium-sized enterprises (SMEs) and over 6,000 accounting firms using Pennylane in France

: the financial orchestrator agent for accountants and SMEs: understanding intent, picking tools, launching jobs, producing reports, asking for validation when needed.

Whichever team you join, the core of the job is the same:

• You will build and harden

in production : LLM call orchestration, tool calling, streaming & events, error recovery, checkpointing and resumability. With security, permissions and cost in mind (agentic RBAC, audit trail, isolated execution, token and latency budgets).

• You will own

: context construction, retrieval, compaction, short- and long-term memory, and the latency / cost trade-offs that come with them.

• You will

, turning business capabilities into well-specified, documented, versioned and tested tools exposed internally and through MCP, and steering agent behaviour (system prompts and instructions, skills, planning and tool-selection strategies, guardrails, anti-prompt-injection).

• You will treat

: golden datasets, LLM-as-judge, human eval, regression tracking and error analysis. Turning production failures into systematic improvements.

• You will collaborate with

• You will learn everything about our company, our teams, and our vision during the first onboarding week.

• You will get familiar with our stack and AI tooling (agent harness, tool registry & MCP, evaluation and observability tooling, model gateway), and have delivered a few small projects which will give you a concrete taste of our tools & processes.

• You will be given time to meet your future stakeholders, and gain a deep knowledge of our product and operations.

• You will be fully in charge of items in our roadmap, defining and prioritizing your tasks autonomously, and will own an agentic use case end to end in production, together with its evaluation set and quality metrics.

• You will be comfortable with our technical stack (

).

• You will contribute to larger cross-team projects.

• You will proactively contribute to the team's roadmap.

• You will work with engineers and data practitioners on improving our agent harness, our evaluation practices and our AI platform.

• You will share your learnings and best practices within the team.

Which means:

• Opportunities to recruit and mentor new team members,

• Increased accountability in project leadership,

• Responsibilities to design and implement new processes, tools and best practices to make sure that your team works even more efficiently.

You're the right candidate if you:

• Have 5–8 years of experience and are very strong in Python

• Hands-on experience building LLM and agentic systems at scale in production: prompting, tool use, context construction, RAG, and handling failure, state and reliability (not just calling a model API).

• Treat evaluation as a first-class discipline: golden datasets, LLM-as-judge, human eval, A/B testing, and measuring agent quality, regressions and edge cases.

• Have a good grasp of applied LLM / ML and AI infrastructure (model serving, vector databases, cost and latency).

• Nice to have: model fine-tuning and post-training (SFT, DPO, RL), MCP, and familiarity with Ruby.

• Have a balanced blend of technical, business and product skills, communicate well (including with non-technical domain experts), and are fluent in English (French is not mandatory).

• A first interview with our Talent Acquisition Manager

• A case study interview to discuss a topic closely related to one of our priorities (75 min)

• A past-project interview to hear about your experience (60 min)

• An interview with our Tech & Product leaders to discuss our company culture (60 min)

• 🌴 Wherever you are based, you'll get 25 vacation days paid by Pennylane

• 💵 You'll have a competitive compensation package

• 📈 You'll get company shares to enjoy a piece of the success story you're building with us

• 🏡 You'll have a budget to turn your home into a more comfortable workspace, as well as a monthly allowance to work from a coworking space whenever you feel like it

• ⛹️ Through our partner Gymlib, you'll have access to 8,000 fitness spaces in Europe and more than 300 wellness activities

• 🇬🇧 You'll have access to Busuu to perfect your English or your French

• 💻 You'll get the latest Apple equipment

• 🏢 Depending on the team and the requirements of the position, you'll be able to work remotely from your country of residence, as long as it is in Europe and within a maximum time difference of two hours from the CET time zone

• 🎉 We regularly come together for company events such as Tech Days (which bring remote Pennylaners together every 2 months) and our annual company seminar

If you are based in France, you'll have a French contract following French regulation, on top of the additional perks: 6 to 12 RTT, 5 weeks of PTO, lunch credits (Swile), Alan Blue healthcare cover, and regular events in cities where Pennylaners are mostly present (Lyon, Bordeaux, Nantes…). We're working on providing those last advantages to people based outside of France as well, though it can be more complex depending on the country.