Fullstack Software Engineer RoR/JS

Stack

Responsibilities

• ▹Build and refine infrastructure supporting internationalization (multi-language, localized user journeys)
• ▹Design and deploy AI-driven tools and automated workflows for lead acquisition and personalization at scale
• ▹Implement and enhance visitor tracking systems that turn raw data into actionable growth insights
• ▹Design and develop robust APIs connecting internal tools with the broader fintech ecosystem
• ▹Run high-velocity experiments: A/B tests, white-label integrations, predictive lead scoring, optimized acquisition funnels
• ▹Maintain and optimize the public website and registration funnels for conversion across all markets

Requirements

• ▹At least 2+ years of professional experience as a Software Engineer
• ▹Strong command of Ruby on Rails; proficiency in a JS framework (Vue/Nuxt) is a major plus
• ▹Effective use of AI tools (LLMs, Copilots, etc.) and automation to move faster and smarter
• ▹Fluent in French and English (B2/C1); German is a bonus
• ▹Energized by a fast-changing startup environment, comfortable collaborating with Data, Sales, and Marketing

Nice to have

• ▹Familiarity with data tools (GTM, Segment) or data visualization (Datastudio, Looker)
• ▹Knowledge of digital marketing (paid acquisition, conversion, SEO)

Soft skills

What we offer

• ▹25 paid vacation days, competitive compensation, company shares
• ▹Home-office setup budget and monthly coworking allowance
• ▹Gymlib wellness access, Busuu language learning, latest Apple equipment
• ▹Flexible remote work within Europe
• ▹Regular Tech Days and annual company seminar

About the company

Pennylane is one of the fastest-growing fintechs in France. In five years it has raised a total of €400 million — including from Sequoia — now employs over 1,000 people across 25+ nationalities, and is used by more than 900,000 SMEs and 6,000 accounting firms in France (4.6/5 on Glassdoor).