--- title: 'Senior Backend Engineer (Go) at Prelude' canonical: 'https://feeny.ai/job/senior-backend-engineer-go-prelude-paris-4es7g5djy16b' type: 'job' last_seen: '2026-09-15' --- # Senior Backend Engineer (Go) at Prelude - **Company:** Prelude - **Location:** Paris, France - **Employment:** full-time - **Work type:** hybrid - **Posted:** 2026-02-23 - **Last confirmed live:** 2026-09-15 - **Apply:** https://jobs.ashbyhq.com/Prelude/c196eb55-a63b-43d4-beb2-ee9a5524f13d/application **Skills:** Go, DynamoDB, SQS, Redshift, Lambdas, gRPC, Rust, TypeScript, React, Vue, Next on Vercel > Build and scale distributed systems using Go, DynamoDB, and cloud services for Prelude's user authentication platform. The role involves developing full-stack apps, maintaining fraud prevention models, and collaborating with clients to deliver high-performance features. ## 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 and scaling a distributed system using Go, DynamoDB, SQS, Redshift and Lambdas - Building a snappy full-stack app using cutting-edge tech (including Next on Vercel, gRPC) - Working on the next version of the [Prelude API](https://docs.prelude.so/introduction/welcome-to-prelude), which we strive to be industry-leading in terms of usability, performance and functionality - Ensuring that our services are scalable, extensible, reliable, and performant - Helping deploy and scale our fraud prevention model to hundreds of large customers - Developing and maintaining internal tools to improve developer efficiency - 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 APIs What are we looking for? - Years of experience designing and engineering large-scale systems - Strong coding skills in Go - any experience with Rust, TypeScript or similar is a huge plus - A preference for simplicity vs complexity, with intuition for what will scale effectively - A product led mindset, keen to code for the output and the impact - Fluent/professional English given our international team - Any experience building frontends with modern frameworks like React or Vue is another huge 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. ## About Prelude ## Company Overview - **One-liner**: Prelude provides a unified trust and onboarding platform that uses device, network, and carrier signals to verify users and prevent fraud. - **Entity Type**: Private (Series A, $20M raised in May 2026) - **Headquarters**: Paris, France - **Founded**: Not publicly available - **Founders**: Matias Berny ## Core Business - Primary industry/industries: Trust and safety, identity verification, fraud prevention, communication APIs - Target customers: B2B – digital businesses (fintech, social, gaming, e‑commerce) that need to onboard legitimate users while stopping bots, fake accounts, and fraud - Mission or purpose statement: "The trust layer between your signups and your business." ## Products & Services - **Verify**: OTP verification across SMS, WhatsApp, RCS, Voice, and Email – 230+ regions, 95% success rate - **Watch**: Pre-KYC risk scoring that blocks fake signups before they cost you money - **Intel API**: Carrier‑grade intelligence (SIM status, number reputation, connection quality) queried in real time - **Auth**: Full authentication stack for signup, login, social, password, with persistent trust and session management - **Notify**: Reliable transactional messaging on the same rails as Verify ## Market Standing - **Valuation**: Not disclosed - **Key Metric**: Total funding $27M ($20M Series A led by 20VC, plus prior rounds from Singular, Seedcamp, Deel, FDJ UNITED Ventures); annual revenue not disclosed - **Notable Investors/Partners**: 20VC (lead), Singular, Seedcamp, Deel, FDJ UNITED Ventures; customers include BeReal, Sunday, Suno, Voodoo - **Growth Signals**: 6x revenue growth and 6x customer base expansion over the past year; expanding into Auth and Intel products; SOC 2 Type II, ISO 27001, and GDPR certified ## Competitive Advantages - **Unified platform** that replaces multiple vendors (verify + auth + fraud) with one integration - **Deep telco partnerships** provide direct carrier routes and network‑level signals not available from pure‑software competitors - **99% fraud reduction** and **30% cost reduction** reported by customers - **Device‑level fingerprinting** and **behavioral monitoring** that work even for AI agents and advanced bots ## Strategic Focus - Deeper telco partnerships and expansion of Lookup API coverage across Europe and beyond - Continued investment in machine learning models that convert raw signals into actionable trust scores - Scaling engineering, telco partnerships, and customer success teams to support rapid growth ## Why Work Here - **Hybrid work model** – most roles based in Paris, with some fully remote positions (e.g., Founding AE – USA) - **Engineering culture** – building critical infrastructure for the AI age; teams work on device fingerprinting, real‑time scoring, Go backend, and full‑stack development - **Open roles** include Backend Engineer (Go), Full‑Stack Engineer, Software Engineer – Internal Tools, Founding Device Fingerprinting Engineer, and sales/customer support positions - **Salary transparency** – posted ranges: BDR €57K, Mid‑Market AE €150K, Enterprise AE €170K–€180K (Paris) - **Impact** – product decisions affect millions of user onboarding flows for high‑growth companies ## Sources 1. [Prelude website](https://prelude.so/) 2. [Prelude Careers (Ashby)](https://jobs.ashbyhq.com/prelude) 3. [Prelude Series A Announcement](https://prelude.so/blog/serie-a-prelude) 4. 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