Senior AI Engineer 🇪🇺

Are you looking to have an impact on the daily life of millions of entrepreneurs in France (and tomorrow in Europe)? Are you looking for a work environment that values trust, proactivity, and autonomy? Are our Engineering principles aligned with your vision? Then Pennylane is the right place for you!

Our vision
We aim to become the most beloved financial Operating System of French SMEs and Accounting Firms (and soon, European ones). We help entrepreneurs rid themselves of time-consuming tasks related to accounting and finance while giving them access to the key financial information they need to make the best decisions for their business.

About us
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

WHY this position is of utmost importance to reach our mission
Pennylane is becoming the financial OS of European SMEs and accounting firms. And a growing share of the work done inside our product will come from agents, not only from humans. Our AI strategy operates at three layers: verticalized AI embedded in the product (Copilot & Autopilot), an agent interface that makes Pennylane readable and actionable by AIs (tools, MCP), and the Pennylane orchestrator agent itself (Studio Assistant).
Models are commoditizing fast. What makes the difference is everything around them: the harness, the context, the tools, the guardrails. And the evaluation that proves it works on real accounting workflows. That is exactly what this role owns.
By joining us as an AI Engineer , you will have a pivotal role in large projects, bringing your software engineering and applied LLM / agentic systems expertise to help us meet our high delivery standards, at scale and with the level of trust our users require.

HOW you will contribute to the company as an AI Engineer
As an AI Engineer , you will be part of one of our ML & AI teams (25+ people, growing from 2 to 5 teams by the end of 2026), depending on your profile and our needs:

• AI Capabilities & Infrastructure (CAPI) : the shared foundations every squad builds on: agent harness, agentic runtime & sandboxing, model gateway, tool registry & MCP, guardrails, observability, LLM FinOps, and reusable AI capabilities.

• Agent Behaviour : making our agents behave correctly, safely and measurably: behaviour steering, domain tuning, evaluation methodology & harness, and later model fine-tuning.

• Studio Assistant : 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 agentic loops 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 & memory engineering : context construction, retrieval, compaction, short- and long-term memory, and the latency / cost trade-offs that come with them.

• You will make Pennylane usable by agents , 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 evaluation as a first-class discipline : golden datasets, LLM-as-judge, human eval, regression tracking and error analysis. Turning production failures into systematic improvements.

• You will collaborate with Product teams and domain experts (accountants) on live use cases : ComptAssistant, Studio Assistant, MCP, document extraction, Autopilot bookkeeping, revision. To make sure that fulfilling real user needs is always at the center of what we do.

• Stay Ahead of the Curve: Continuously monitor the AI landscape for emerging trends, State-of-the-Art (SOTA) models, and breakthrough research (e.g., new LLM architectures, multimodal AI, and optimization techniques).

WHAT you can expect from your life at Pennylane
Within one month:

• 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.

Within 3 months:

• 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.…

Source: Arbeitnow (https://www.arbeitnow.fr/jobs/companies/pennylane-sas/senior-ai-engineer-paris-278677)