> Markdown version of [/jobs/ext/2960797-fullstack-engineer](https://www.wearedevelopers.com/jobs/ext/2960797-fullstack-engineer). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Fullstack Engineer - **Company:** Número De - **Location:** Barcelona, Spain (Remote available) - **Contract:** Permanent contract - **Skills:** Application Programming Interfaces (APIs), Artificial Intelligence, Amazon Web Services, Data Analysis, Microsoft Azure, BigQuery, Software as a Service, Code Generation, Software Debugging, Software Design Patterns, Human-Computer Interaction, Software Tools, Software Engineering, SQL Databases, TypeScript, AI Infrastructure, Data Processing, Google Cloud, ReactJS, Backend, Information Technology, Data Analytics, Front End Software Development, Api Design, Data Pipelines - **Published:** September 17, 2026 - **Apply:** https://www.adzuna.es/contact-us.html ## About the Role + 7+ years of professional software engineering experience, including experience building and operating multi-tenant SaaS products in production. + Proven track record of owning features or products end-to-end, from problem definition through implementation and ongoing improvement. + Strong professional experience with Go, particularly for backend services, APIs, data processing, and production operations. + Strong TypeScript and modern React skills, with an understanding of how to present complex data clearly and effectively. + Comfortable working across the full technology stack, with the ability to take a feature from data model and backend services through to the user interface. + Experience developing on public cloud platforms, preferably Google Cloud Platform, with AWS or Azure experience also relevant. + Working proficiency in SQL and experience working with analytical data stores such as BigQuery. + Strong product-oriented mindset, with an ability to understand why something should be built and assess whether it delivers value for users. + Demonstrated experience using AI tools across the software engineering workflow and the ability to articulate their practical benefits and limitations. + Strong understanding of software engineering practices, design patterns, architecture, scalability, reliability, and maintainability. + Ability to provide technical direction and establish strong engineering practices for other team members. + Comfortable working with ambiguity and rapidly changing priorities, with the ability to identify the right problems to solve rather than simply implementing predefined solutions. + Excellent written and verbal English communication skills. + Highly self-organized, goal-oriented, proactive, and self-motivated. + Confident, thorough, and persistent approach to solving complex technical and product challenges. Preferred qualifications: + Experience with FinOps or cloud cost management products. + Knowledge of AI infrastructure, cloud economics, or AI workload cost optimization. + Bachelor's degree in computer science, engineering, or a related field, or equivalent practical experience. + A portfolio or demonstrated track record of products, features, or technical projects you have built throughout your career. ## Description As a Senior Full-Stack Engineer, you will take end-to-end ownership of a product helping organizations understand and optimize the rapidly growing costs of AI workloads. You will work across backend services, APIs, data processing, and modern frontend experiences, turning complex cloud and AI spending data into clear, actionable insights. This is a high-impact opportunity to join an R&D team working on a young product in a rapidly evolving market where you can directly influence both the technology and product direction. You will collaborate closely with product and engineering stakeholders while having significant autonomy to identify problems and define solutions. The role combines strong engineering fundamentals with product thinking, requiring you to care equally about technical quality and customer outcomes. You will also work AI-augmented throughout your development workflow, exploring how emerging tools can improve engineering velocity without compromising quality or reliability. Accountabilities + Own features end-to-end, from understanding customer problems and defining solutions through design, implementation, release, monitoring, and continuous iteration. + Take responsibility for the reliability, usability, quality, and measurable business impact of the features you deliver. + Proactively identify opportunities and propose improvements rather than relying solely on predefined specifications. + Develop and scale backend services in Go, including APIs, data processing pipelines, and production-grade services. + Build modern product experiences using TypeScript and React, presenting complex cost and usage data in clear, intuitive, and trustworthy interfaces. + Design API-first capabilities that can be consumed by both human users and AI agents. + Work with large volumes of cloud cost and usage data and translate them into useful product experiences and actionable insights. + Develop a strong understanding of AI spending models, including token and model pricing, inference economics, GPU costs, and the allocation of usage across teams and initiatives. + Apply FinOps principles and customer needs to product and technical decisions where relevant. + Use AI tools throughout the engineering lifecycle, including codebase exploration, prototyping, code generation and review, debugging, testing, and documentation. + Evaluate the effectiveness and limitations of AI-assisted development and establish appropriate quality standards for its use. + Contribute to thoughtful architecture, design reviews, engineering practices, and technical guardrails that enable rapid but reliable delivery. + Mentor peers, share knowledge, and help raise engineering standards across the team. + Collaborate effectively in a distributed environment and contribute to product decisions in a market characterized by significant ambiguity and rapid change. ## Related Videos - [Shipping Faster with Less: Render on Cloud Hosting, AI Workloads, and the Future of DevOps](https://www.wearedevelopers.com/videos/1894-shipping-faster-with-less-render-on-cloud-hosting-ai-workloads-and-the-future-of-devops) - [Data Science in Retail](https://www.wearedevelopers.com/videos/586-data-science-in-retail) - [Watch Tests Go Brrrr! : Getting Started with Cypress in ReactJS](https://www.wearedevelopers.com/videos/282-watch-tests-go-brrrr-getting-started-with-cypress-in-reactjs) - [Developing the Backend with Stefan Lingler, CTO at Shpock](https://www.wearedevelopers.com/videos/100360-developing-the-backend-with-stefan-lingler-cto-at-shpock) - [Meet Your New BFF: Backend to Frontend without the Duct Tape](https://www.wearedevelopers.com/videos/682-meet-your-new-bff-backend-to-frontend-without-the-duct-tape) - [Build and Deploy a Fullstack App with Open Source Tooling](https://www.wearedevelopers.com/videos/775-build-and-deploy-a-fullstack-app-with-open-source-tooling) ## Related Articles - [Fully Remote Software Engineer Jobs](https://www.wearedevelopers.com/magazine/447-fully-remote-software-engineer-jobs) - [Top-Paying Tech Jobs (with Salaries)](https://www.wearedevelopers.com/magazine/372-top-paying-tech-jobs-with-salaries) - [Is Software Engineering Over-Saturated?](https://www.wearedevelopers.com/magazine/418-is-software-engineering-over-saturated) - [The 12 Best Jobs for Software Engineers](https://www.wearedevelopers.com/magazine/401-the-12-best-jobs-for-software-engineers) - [Why Upskilling And Reskilling is Important For Developers](https://www.wearedevelopers.com/magazine/428-why-upskilling-and-reskilling-is-important-for-developers) - [Highest Paying Tech Companies for Developers](https://www.wearedevelopers.com/magazine/220-highest-paying-tech-companies-for-developers)