Senior Backend Engineer - Semantic AI for Enterprise Data

Cirql One GmbH; Barcelona; Hybrid; EUR 85,000 - 110,000; Full time

Benefits offered by this job

Full transparency

Regular team onsites

Hybrid and flexible

Competitive compensation

Growth opportunities

Job summary

Cirql One GmbH is hiring a hands-on backend engineer to build the semantic core that turns raw enterprise data into business-meaningfully structured information for AI agents. You’ll own features end-to-end, shape architecture, and work closely with solutions engineers, product, and customer success in a hybrid Barcelona setting.

The role emphasizes pragmatic decision-making, clear communication, and cross-functional collaboration, with a focus on data-intensive systems, modern cloud

Qualifications

• 4+ years of professional backend development in Python.
• Production experience with FastAPI or a comparable Python web framework and a track record of designing clean 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 containerized services in production on Azure, GCP or similar, including CI/CD and infrastructure as code.
• Demonstrated use of AI coding tools in production workflows with strong validation and quality control.
• You write automated tests as part of the work, and design test scenarios that catch real-world edge cases.
• Fluent English, written and spoken.

Responsibilities

• Build the semantic core. Design and evolve the platform that transforms raw enterprise data into structured, business-accurate meaning usable by AI agents.
• Own features end-to-end from schema design to backend logic and APIs to the product surface.
• Shape architecture with principled technical decisions balancing long-term coherence and early-stage speed.
• Amplify impact with AI across design, implementation, testing, and documentation to move fast while ensuring correctness.

Skills

Python

Backend development

PostgreSQL

API design

Azure / GCP

AI tooling

Testing

English communication

Education

Bachelor's degree in Computer Science

Tools

FastAPI

Job description

Cirql One GmbH is hiring a hands-on backend engineer to build the semantic core that turns raw enterprise data into business-meaningfully structured information for AI agents. You’ll own features end-to-end, shape architecture, and work closely with solutions engineers, product, and customer success in a hybrid Barcelona setting.

The role emphasizes pragmatic decision-making, clear communication, and cross-functional collaboration, with a focus on data-intensive systems, modern cloud