Full-Stack Engineer

About Prelude

Prelude is redefining how companies authenticate and onboard users - turning what's traditionally a cost center into a growth lever. Our flagship product lets businesses send OTP codes with the best price-to-conversion ratio on the market, dynamically selecting the most effective channel in real time (optimized SMS, WhatsApp, and more) while actively blocking spam and fraud that legacy providers miss. Founded in 2022 by former Zenly team members who lived the pain of broken SMS authentication firsthand, we're already serving fast-growing companies across Europe and are expanding into the US. But authentication is only the starting point - we're building the platform for trust at scale, with an ambitious roadmap of market-defining products ahead. Why join us

Today, we're a team of 60 and growing, based in Paris, building products that power secure and high-performance user onboarding for companies across the world. We believe small, highly skilled teams outperform large, fragmented organizations, and we are intentional about staying focused on impact, quality, and speed. We operate with a flat org structure and value in-person collaboration, which helps ideas move faster, decisions stay grounded, and teams take full ownership of what they build. Our values

• CareWe care deeply about our customers, our teammates, and the quality and reliability of what we ship. - Bias for ActionWe move fast, test in the real world, and iterate quickly rather than over-optimizing in theory. - We take responsibility end to end, from identifying problems to delivering outcomes and learning from results.