Full-Stack Engineer

Prelude; Paris; Hybrid; EUR 70,000 - 110,000; Full time

Benefits offered by this job

BSPCEs

Hybrid work (3 in-office / 2 remote)

Remote work 4 weeks/year

Health insurance

Gym membership

Meal vouchers

Snacks & drinks

Annual offsite

Work gear provided

Job summary

Prelude is redefining how companies authenticate and onboard users, delivering fast, cost-efficient OTP delivery while blocking fraud. The team in Paris focuses on building a scalable, secure platform with a strong emphasis on UX and performance.

You will develop across the stack, from React frontends to Go backends, while collaborating with a global team. Expect a product-led environment with a mix of in-office and remote work, and a roadmap of groundbreaking features ahead.

Qualifications

• Frontend and backend experience across the stack
• Strong React and TypeScript fundamentals
• Experience designing reliable APIs and services
• Affinity for simple, scalable designs
• Product-focused mindset with UX awareness
• Fluent English within an international team
• Nice to have Rust, gRPC or AWS serverless experience

Responsibilities

• Build polished, high-performance UIs using React and TypeScript
• Own features end-to-end—from frontend to backend
• Work across the stack with Go, DynamoDB, SQS, Redshift and Lambdas
• Shape and build the next Prelude API for usability and performance
• Design and build internal tools and dashboards to improve efficiency
• Help deploy and scale fraud prevention models for customers
• Interact with clients daily to tailor features to their needs
• Participate in on-call rotations to ensure reliability

Skills

Frontend development

React

Go backend

TypeScript

Full-stack

UX sensitivity

English fluency

AWS serverless

Rust / gRPC

Tools

AWS Lambda

DynamoDB

SQS

Redshift

Go

TypeScript

Job description

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

• Care
  We care deeply about our customers, our teammates, and the quality and reliability of what we ship.

• Bias for Action
  We move fast, test in the real world, and iterate quickly rather than over-optimizing in theory.

• Ownership
  We take responsibility end to end, from identifying problems to delivering outcomes and learning from results.

What will you be doing?

• Building polished, high-performance user interfaces using React and Typescript, with a strong focus on usability, speed, and design quality

• Owning features end to end — from the React frontend through the Go backend, APIs, and data layer

• Working across the stack on our distributed system using Go, DynamoDB, SQS, Redshift, and Lambdas

• Shaping and building the next version of Prelude API, which we strive to be industry-leading in terms of usability, performance, and functionality

• Designing and building internal tools and dashboards that improve developer and team efficiency

• Helping deploy and scale our fraud prevention model to hundreds of large customers

• Interacting with clients on a daily basis to assist them and build features around their needs

• Participating in on-call rotations to guarantee the stability and reliability of our services

What are we looking for?

• Strong experience building frontends with modern frameworks : React is ideal, Vue or similar also welcome

• Solid backend skills in Go or TypeScript, with the ability to design and build reliable APIs and services

• Years of experience working across the full stack, from UI to infrastructure

• A preference for simplicity vs complexity, with intuition for what will scale effectively

• A keen eye for product and UX — you care about what the user sees and experiences, not just what the code does

• A product-led mindset, keen to code for the output and the impact

• Fluent/professional English given our international team

• Any experience with Rust, gRPC, or AWS serverless (Lambda, DynamoDB, SQS) is a plus

What can we offer you?

• Competitive compensation package with BSPCEs

• 3 days in-office in central Paris, with 2 days WFH; and 4 weeks of remote work per year

• 100% travel to the office subsidised

• Health insurance via Alan

• Urban Sports Club gym membership

• We will provide you with the gear you need for your role (a laptop and a phone, for on-call rotations)

• Swile meal vouchers

• Free snacks and drinks in the office

• An annual offsite in a great location (last one was at La Pradet!)

• The opportunity to build something from 0-1, and make an impact every day

Interview process

• Meet a member of the Talent team

• Technical assessment

• In-person interview (system design, coding)

• Final meeting with CEO

We don’t expect you to ace all these stages, we will evaluate your creativity and how you approach difficult problems. You should consider applying even if you don’t meet all the criteria.