Senior Product Engineer: Full-stack with 80% BackendAbout LongtailLongtail is building an intelligent decision-streaming platform that helps airlines make smarter, faster commercial decisions in real time. Combining automation, proprietary algorithms, AI, and live data, our technology helps airlines optimize pricing, availability, and product flexibility across thousands of routes worldwide.We're a fast-growing, international team solving complex, real-world problems at scale.The RoleYou'll help build and evolve our new conversational analytics and intelligent alerting product, as it moves from beta to a scalable, production-ready platform.This is a full-stack role with roughly 80% backend, 20% frontend. You'll own features end to end: understanding customer problems, designing solutions, building and deploying them, and supporting them in production.A key challenge on this team is building AI-native software customers can trust.We're looking for someone with 7+ years of engineering experience, including time spent operating production systems,



not just shipping them.What You’ll Do- Design and build backend services, APIs, and customer-facing capabilities: including conversational analytics, intelligent alerting, reports and saved analyses, and AI-powered/agentic workflows- Own features end to end, from customer problem through to production- Build reliable, asynchronous workflows with orchestration, error handling, recovery, and observability baked in- Integrate with data, analytics, and AI model platforms- Design resilient systems that handle failures gracefully- Contribute to the React frontend when a feature calls for it- Improve testing, observability, security, and performance across the platform- Make pragmatic technical decisions as the product evolves, and help shape engineering standards and architecture as we growWhat We’re Looking ForYou're a strong backend engineer who:- Has built and operated production SaaS products- Has strong API, database, and SQL

📌 Senior Software Engineer (Barcelona)
🏢 Longtail Technologies
📍 Barcelona