Senior.NET Backend Engineer

We are hiring a true senior backend engineer to help us scale and evolve a long-running, production SaaS platform used daily by ecommerce merchants at real volume. Por favor, lea detenidamente la siguiente descripción del puesto para asegurarse de que encaja con el perfil antes de enviar su solicitud. This role is not suitable for developers who require close supervision or step-by-step guidance . We are looking for someone who can take full ownership of backend features end-to-end and deliver reliable, well-tested, production-ready solutions . If you enjoy responsibility, autonomy, and building systems that matter in the real world, this role will suit you very well. The Product We build an AI-enhanced ecommerce content platform that helps merchants improve conversion rates, customer trust, and organic visibility across traditional search engines (Google) and emerging AI-driven search channels (ChatGPT, Perplexity, etc.). Our platform: Serves millions of page views Manages thousands to tens of thousands of products per client Uses LLMs to generate, maintain, and validate structured Q&A and content at scale Has been in continuous production for 15 years Is profitable, stable, and growing This is not a greenfield experiment or a short-lived startup — it is a mature product with real customers, real data, and real technical challenges. What You Will Own Design and implement backend features in C# / .NET Build and maintain Azure-based services (App Services, Functions, Storage, SQL) Work hands-on with SQL Server : schema design, indexing, query optimization Integrate AI / LLM services where they add clear, measurable value Deliver code that is tested, readable, maintainable, and production-ready Understand requirements, ask the right clarifying questions, and execute without micromanagement You will have meaningful influence on how the system evolves technically over time. This Role Requires (Non-Negotiable) You must have done the following professionally: Built and maintained production .NET backend systems for several years Worked on a SaaS or high-traffic system , not only internal tools Be very solid in programming fundamentals (data structures, async flows, error handling, separation of concerns) Debugged real production issues and taken responsibility for fixing them Worked independently with minimal supervision Have 6+ years of full-time professional programming experience Be fluent in English Practical requirements: Spanish residency and valid working permit Ability to meet face-to-face in Barcelona every ~2 months Technical Expectations Strong C# / .NET backend experience Solid SQL Server knowledge (queries, indexes, schema design) Azure experience in real production environments Familiarity with REST APIs and async patterns Comfortable reading, understanding, and improving existing codebases Some frontend experience (MVC, JavaScript, basic UI logic) Experience with: LLM APIs (OpenAI, Azure AI) Shopify / BigCommerce …is a bonus , not a substitute for strong backend fundamentals. How We Work Small team, high trust Clear, written requirements and expectations Very little hand-holding Strong focus on quality, correctness, and follow-through Preference for calm, thoughtful engineering over rushed output We value people who care about doing things properly and take pride in their work. xcskxlj Practical Details 100% remote (Catalonia-based) Flexible working hours Competitive salary: €40,000 – €65,000 , depending on demonstrated seniority and ownership level Long-term role with room to grow into technical and architectural leadership Hay opciones de teletrabajo/trabajo desde casa disponibles para este puesto.