Top Tech Jobs & Startup Jobs in Barcelona

Own machine learning projects from exploration through production, building reliable agentic LLM systems for clinical settings. Develop evaluation datasets, offline and online testing harnesses, LLM-as-judge workflows, regression tests, and production feedback loops. Improve models through prompting, retrieval, distillation, and fine-tuning. Partner with product, clinical, and engineering teams, while reviewing code, sharing knowledge, and mentoring junior engineers.

Develops technical and economic cases for industrial heat pump installations across Europe. Responsibilities include interpreting P&IDs, creating process flow diagrams and heat and mass balances, modeling steam demand and energy economics, defining plant data requirements, conducting site visits, installing metering equipment, engaging plant staff, leading technical customer calls, addressing objections, and coordinating internal engineering, sales, project management, and external partners.

Manage the post-onboarding lifecycle for SMB customers across LATAM, focusing on customer health, retention, expansion, and adoption. Build trusted relationships, engage C-suite stakeholders, identify growth opportunities, maintain accurate customer records in Salesforce, advocate for customer needs internally, and collaborate across product, sales, and leadership to improve customer experiences.

Own the AI agenda across Customer Operations by identifying, implementing, monitoring, and optimizing AI features such as chat and email agents. Manage multiple concurrent projects, align stakeholders, translate operational pain points into automation opportunities, and improve processes across Customer Support and Payments, Fraud & Verification. Track post-launch performance, resolve issues, and drive continuous operational excellence through analytical, creative, and cross-functional problem-solving.

Provide pre- and post-sales technical support for flexible laminates (FCCL, coverlays, polyimide films); collaborate with sales and cross-functional teams to develop solutions, run trainings, analyze product performance, support audits, and represent the company at industry events.

Lead global recruitment, hiring mechanisms, mobilization, compliance, payroll/benefits, and lifecycle management for contracted personnel under a multi-year State Department project. Maintain global expert roster, ensure regulatory and host-country compliance, and meet mobilization and performance timelines.

Nango is hiring Senior and Staff Backend Engineers to design, build, and optimize backend systems and APIs, collaborating with customers and driving product strategy.

Design and deliver data-rich, production-ready UX for an open-source observability platform. Lead end-to-end product design from discovery to shipped features, create component-based patterns and design system work, prototype rapidly (including AI-assisted workflows), and engage customers to validate workflows for developer and SRE audiences.

Own execution and optimization of paid acquisition campaigns (primarily Google Ads and Apple Search Ads), manage large advertising budgets, run A/B tests, build reporting with AppsFlyer/GA/Tableau, partner with cross-functional teams to improve funnels, and drive efficient mobile user acquisition.

Execute and improve manual and automated Android test cases, find and track defects, collaborate with Agile teams, enhance test coverage and QA processes, and mentor peers to ensure mobile app quality.