Senior Software Engineer
Software Engineering
San Sebastián, Gipuzkoa, Spain
Multiverse Computing
Multiverse is a well-funded, fast-growing deep-tech company founded in 2019. We are the largest quantum software company in the EU and have been recognized by CB Insights (2023 and 2025) as one of the 100 most promising AI companies in the world.
With 180+ employees and growing, our team is fully multicultural and international. We deliver hyper-efficient software for companies seeking a competitive edge through quantum computing and artificial intelligence.
Our flagship products, CompactifAI and Singularity, address critical needs across various industries:
· CompactifAI is a groundbreaking compression tool for foundational AI models based on Tensor Networks. It enables the compression of large AI systems—such as language models—to make them significantly more efficient and portable.
· Singularity is a quantum- and quantum-inspired optimization platform used by blue-chip companies to solve complex problems in finance, energy, manufacturing, and beyond. It integrates seamlessly with existing systems and delivers immediate performance gains on classical and quantum hardware.
You’ll be working alongside world-leading experts to develop solutions that tackle real-world challenges. We’re looking for passionate individuals eager to grow in an ethics-driven environment that values sustainability and diversity.
We’re committed to building a truly inclusive culture—come and join us.
As a Software Engineer you will
· Join a world-class team of Quantum and AI experts with an extensive track record in both academia and industry.
· Work with Fortune-500 customers from government and private sectors.
· Contribute to our groundbreaking compressing tool
· Tackle high value open problems from industry.
· Take on technical leadership and work together with software and DevOps engineers as well as our machine learning and quantum experts to industrialize Multiverse’s core technologies
Required Qualifications
Software Engineering
Proven track record designing and implementing production-grade software running under real load
Solid grasp of clean architecture, separation of concerns, SOLID principles, testability and maintainability as first-class concerns
Experience with software design patterns and sound judgment on when (and when not) to apply them
Understands service-level architecture: API design, layered architectures, event-driven patterns, and how to structure code that outlives its author
Good grounding in software security principles: input validation, secret management, dependency auditing, container hardening, secure API design
Experience with containerized deployment fundamentals (Docker) and CI/CD concepts
Soft Skills
Proposes solutions to unfamiliar problems: research first, presents alternatives with trade-offs, doesn’t wait to be told the answer
Breaks complex cross-repo issues into sequenced, followable steps
Acts as developer, mentor, and reviewer in the same sprint – writes production code, gives PR feedback to mid-level engineers, upholds review standards
Communicates technical risk clearly – surfaces blockers early with context
Comfortable with ambiguity and working under pressure; self-directed
Collaborates cross-functionally (MLOps, DevOps, Platform Engineering) without needing a manager to mediate
Preferred Qualifications
ML & LLM Exposure
Exposure to PyTorch and/or HuggingFace Transformers (fine-tuning, inference, compression workflows)
Familiarity with ML infra concepts: training orchestration, experiment tracking, GPU job scheduling
Awareness of LLM techniques: distillation, quantization, pruning, inference serving
Some exposure to GPU-aware engineering (CUDA, mixed precision, multi-GPU) is a plus
Tooling & Infrastructure
ECR, ArgoCD/Helm, structured CI/CD pipelines beyond basic Docker
Async long-running job orchestration patterns
CLI frameworks, Python packaging, Docker multi-stage builds
General comfort moving across CLI tooling → API services → infra glue
Perks & Benefits
· Indefinite contract.
· Equal pay guaranteed.
· Variable performance bonus.
· Signing bonus.
· We offer work visa sponsorship (If applicable).
· Relocation package (if applicable).
· Private health insurance.
· Flexible remuneration: hospitality and public transportation.
· Eligibility for educational budget according to internal policy.
· Hybrid opportunity.
· Flexible working hours.
· Language classes and discounted lunch options
· Working in a high paced environment, working on cutting edge technologies.
· Career plan. Opportunity to learn and teach.
· Progressive Company. Happy people culture
As an equal opportunity employer, Multiverse Computing is committed to building an inclusive workplace. The company welcomes people from all different backgrounds, including age, citizenship, ethnic and racial origins, gender identities, individuals with disabilities, marital status, religions and ideologies, and sexual orientations to apply.