Senior Software Engineer C# - FLEXIBLE WORKING

We are hiring a Senior Software Engineer for a fixed-term contract ending in June 2026, based in Barcelona or Zaragoza with a hybrid working model.
This role is with a leading European deep-tech company working at the intersection of AI, machine learning, and advanced computing. You will collaborate with world-class engineers and researchers to industrialize cutting-edge technologies and deliver solutions to large enterprise and public-sector customers.

Signing bonus upon joining and a retention bonus at contract completion
Relocation support if applicable
Fixed-term contract until June 2026
Hybrid working model with flexible hours
Develop, deploy, and maintain production-grade software systems across frontend and backend
Work closely with software, DevOps, ML, and research teams to industrialize core technologies
Contribute to high-impact projects for large enterprise and government customers
Maintain high engineering standards through testing, documentation, and clean code practices

Bachelor's degree or higher in Computer Science, Engineering, or equivalent industry experience
Strong expertise in Python; additional experience with Rust or C/C++ is a plus
Experience level aligned with junior (1–2 years), mid (3+ years), or senior (5+ years) profiles
Experience in frontend and backend development
Proficiency with TypeScript and frameworks such as Flask or FastAPI
Experience deploying software in cloud environments such as AWS
Hands-on experience working with LLMs and related tools (HuggingFace, OpenAI APIs, vector databases)
Experience with distributed systems or frameworks such as Ray or Spark
Experience working in cross-functional teams and designing scalable software architectures

This is a fixed-term contract role ending in June 2026.