Senior Backend Engineer (Engagement & Monetization)

Who we are Yubo is the Social Discovery app to make new friends and hang out online. By eliminating likes and follows, we empower our users to create genuine connections and show up as their true selves. We've pioneered a new way for Gen Z to socialize online, and with millions of active users, our goal is to redefine how we connect today and tomorrow. Our team is international, multicultural and deeply committed to its mission. As the leading platform to socialize online, we have a special responsibility to build a safe digital space for our community. Safety is embedded in our DNA, and our proactive approach focuses on user protection, support, and education. We also work closely with the broader technology industry to share our knowledge and NGOs create industry-leading child protection standards. Join us in this exciting journey and help us shape the future of social interactions! About this role As Yubo continues to scale, we’re entering a new phase of product ambition, especially within our Engagement & Monetization squad , whose mission is to continuously experiment and improve our core business metrics. Following the rollout of our 2026 Tech organization and prepare for the future. We’re looking for a Senior Backend Engineer to join our Backend Experience team , reporting directly to Armand (Engineering Manager). You will be embedded in a multi-disciplinary squad (Mobile Engineers, Product Manager, Designer, Data Analyst), alongside two backend engineers to help you ramp up fast. Your role? Set the technical direction and deliver backend systems that enable continuous experimentation at scale , rolling out services and business logic for millions of users while tracking interactions reliably and safely. Your responsibilities Define technical direction for backend initiatives within the Engagement & Monetization squad. Translate product and monetization goals into actionable backend specifications. Deliver KPI-impacting backend changes that directly contribute to core business metrics. Make sound trade-offs between speed, quality, scalability, and product outcomes, documenting decisions when needed. Ensure production readiness (testing, resilience, observability, operational excellence). Support experimentation by building measurable, well-instrumented, safe-to-iterate systems. Improve tracking and observability to reliably attribute experiment impact Contribute to backend codebase improvements (e.g., TypeScript migration) Mentor engineers through reviews, pairing, and design feedback. Create alignment across squads and proactively manage cross-team dependencies. Strengthen documentation, specs, and onboarding materials to increase squad effectiveness. Our technical environment / Tools we use Backend: Node.js & TypeScript Architecture: Event-driven systems (Kafka, RabbitMQ, NATS) Databases: NoSQL, key-value stores, relational databases at scale Practices: RFC processes, technical specs, structured decision-making Experimentation & Observability: Datadog, Grafana… Who you are You have 8+ years of backend engineering experience , in startup/scale-up environments You are highly proficient in Node.js and TypeScript . You have strong experience designing and scaling APIs (performance, security, observability). You have worked with event-driven architectures (Kafka, RabbitMQ, NATS). You are comfortable designing scalable architectures serving high volumetry. You have deep knowledge of databases (SQL & NoSQL) in production environments. You demonstrate strong engineering best practices (testing, resilience, documentation). You have a strong product mindset and understand how backend decisions impact business KPIs You enjoy mentoring and raising the technical bar within a squad. You communicate clearly, raise trade-offs early, and align stakeholders proactively. You’re comfortable working in English in an international environment. In your first 6 months, you will Ship backend initiatives that measurably improve core Engagement & Monetization KPIs (DAU, conversion, retention, revenue signals). Enable faster, safer experimentation by building systems that are fully instrumented, observable, and easy to iterate on . Increase the squad’s delivery velocity while maintaining high engineering standards. Reduce technical friction by improving architecture clarity, documentation, and decision-making processes. Strengthen the reliability and scalability of backend services supporting millions of users. Raise the overall technical bar within the squad through mentorship and architectural influence. Contribute to structuring the backend organization in preparation for future squad scaling. The recruitment process Phone screen with a Talent Acquisition Manager Interview with Armand (Engineering Manager) Technical test (home assignment + debrief & system design with Backend team) Cultural fit assessments What we offer A highly competitive salary range as well as equity in the company A highly flexible remote work policy, 2 days at the office per month, with monthly team events. We also cover fees for external professional events and meetups (Android Makers, etc…) Great health insurance coverage for both you and your family by Alan, fully paid for by Yubo ! Numerous benefits for parents: additional parental leave, easy access to nurseries and daycare facilities in France. Our approach to privacy & safety As part of your role, you may handle tools and features involving personal data. We expect all employees to demonstrate strong awareness of privacy and safety issues, and to actively support our Privacy & Safety by Design efforts. Join Yubo and help shape the future of Social Discovery while enjoying a culture that values flexibility, well-being, and impact. Here’s how we live our mission every day: Y ou own the impact: Step up, adapt, and make it matter U nconventionally Smart: Hack with intent, borrow smart, build better B e Bold & Resilient: Raise your head, break barriers, keep moving forward O ne team, one mission: No egos, no passengers, just shared wins Trust & Flexibility: Our hybrid model calls for only two office days a month; the rest is up to the rhythm that works best for you. Enjoy Top-notch Benefits Culture is central at Yubo, hence the numerous benefits: Cool Workplace : enjoy our amazing Parisian office and our many hybrid work options Team Activities : participate in get-togethers, events, and team-building activities Family-Friendly : we support parents with childcare options and family-friendly policies Wellness Programs : benefit from comprehensive health insurance, wellness programs, sports classes, and mental well-being initiatives