Backend engineer for enterprise data

At Cirql One, we are building the foundational layer that connects enterprise data to AI: a layer that doesn't just relay information, but genuinely understands it, making business meaning explicit, trusted, and actionable at scale.

• Design and evolve the platform that transforms raw enterprise data into structured, business-accurate meaning usable by AI agents, from data extraction pipelines to semantic storage, versioning, and governance.
• Take a problem from schema design through backend logic and APIs to how it surfaces in the product. You won’t hand things off. You’ll see them through and care about every layer.
• Make principled technical decisions and explain them clearly. Balance long-term platform coherence with the speed that early-stage demands. Push back when it matters and adapt when it doesn't.
• Use the best AI tools across design, implementation, testing, and documentation to move faster, without compromising on correctness and reliability.

• You weigh trade-offs clearly and reach for the right pattern, library, or approach for the problem at hand, not out of habit. You can defend that choice clearly.
• You break down complex problems methodically and reach well-reasoned conclusions. You know how to separate signal from noise, and you're comfortable making decisions under uncertainty without waiting for the perfect answer.
• You express ideas precisely, in code, in writing, and in conversation. You can walk a non-technical colleague through a technical decision without oversimplifying it.
• You share knowledge freely, back the best idea regardless of where it came from, and make the people around you better. You're someone colleagues genuinely want to build with.
• You take initiative on real problems early, don’t wait for permission, and are trusted to own the outcome.
• You want to understand the business problem behind the ticket. You’re eager to learn how enterprises actually run on data, and you seek out the people closest to customers to get it right.
• 4+ years of professional backend development in Python, building data-intensive or distributed systems.
• Production experience with FastAPI or a comparable Python web framework (FastAPI preferred), and a track record of designing clean, well-documented APIs.
• Solid command of PostgreSQL and ORM-based data modeling.
• Proven ability to translate customer and business requirements into well-architected technical solutions.
• Hands-on experience deploying and running containerized services in production on Azure, GCP or similar, including CI/CD, managing environments (dev/staging/prod), and infrastructure as code (e.g. Terraform).
• Demonstrated use of AI coding tools (e.g. Claude Code, Cursor) in production workflows, with strong judgment around validation and quality control.
• You write automated tests as part of the work, not after it, and design test scenarios that catch real-world edge cases.
• Fluent English, written and spoken.
• Будет плюсом: Background in semantic systems: knowledge graphs, ontologies, metadata catalogs, or data governance tooling; Experience building AI agents or agentic workflows, including Model Context Protocol (MCP) integrations and guardrails for AI systems; Experience designing and maintaining data pipelines and ETL/ELT workflows, ideally with a cloud data warehouse such as Snowflake; Exposure to SAP data structures or other enterprise ERP environments. If you don’t have it, we’ll teach you; Experience with microservices or event-driven architectures

• No filtered updates. Everyone knows what we’re building, how the business is doing, and where we’re going.
• We get together in person to plan, build, and spend time as a team.
• Pay that reflects the seniority and impact of the role.
• A hybrid setup at our Barcelona office, with the flexibility to organize your week around your work and your life.
• We’re scaling deliberately, and your scope grows with the company.
• Everyone is deeply invested in the problem and committed to doing the work well.