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# Senior Software Engineer

- **Company:** Longtail Technologies
- **Location:** Barcelona, Spain
- **Contract:** Permanent contract
- **Skills:** Application Programming Interfaces (APIs), Artificial Intelligence, Software as a Service, Databases, Distributed Systems, SQL Databases, ReactJS, Backend, Front End Software Development
- **Published:** September 18, 2026
- **Apply:** https://www.buscojobs.com.es/senior-software-engineer-en-barcelona-ID-372215299

## About the Role

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 DoDesign and build backend services, APIs, and customer-facing capabilities: including conversational analytics, intelligent alerting, reports and saved analyses, and AI-powered/agentic workflowsOwn features end to end, from customer problem through to productionBuild reliable, asynchronous workflows with orchestration, error handling, recovery, and observability baked inIntegrate with data, analytics, and AI model platformsDesign resilient systems that handle failures gracefullyContribute to the React frontend when a feature calls for itImprove testing, observability, security, and performance across the
platformMake 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 productsHas strong API, database, and SQL skillsUnderstands distributed systems, asynchronous processing, and failure modesCares about reliability, observability, security, and maintainabilityUses AI-assisted development tools such as Claude Code, OpenAI Codex, or similar, while applying strong engineering judgementWorking at LongtailWe're a collaborative, distributed team that values transparency, ownership, clear communication, and sustainable ways of working.
You'll have the autonomy to make meaningful technical decisions.

## Description

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 DoDesign and build backend services, APIs, and customer-facing capabilities: including conversational analytics, intelligent alerting, reports and saved analyses, and AI-powered/agentic workflowsOwn features end to end, from customer problem through to productionBuild reliable, asynchronous workflows with orchestration, error handling, recovery, and observability baked inIntegrate with data, analytics, and AI model platformsDesign resilient systems that handle failures gracefullyContribute to the React frontend when a feature calls for itImprove testing, observability, security, and performance across the platformMake 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 productsHas strong API, database, and SQL skillsUnderstands distributed systems, asynchronous processing, and failure modesCares about reliability, observability, security, and maintainabilityUses AI-assisted development tools such as Claude Code, OpenAI Codex, or similar, while applying strong engineering judgementWorking at LongtailWe're a collaborative, distributed team that values transparency, ownership, clear communication, and sustainable ways of working.You'll have the autonomy to make meaningful technical decisions.We're committed to building a respectful and inclusive workplace where people can do their best work.Competitive Package with base + bonus + equity + Benefits (Private health insurance and Pension contribution, Learning and Development budget, Childcare, transport and meal vouchers...).#J-*****-Ljbffr


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