Senior Backend Engineer (Python)

About Scalera Scalera is an ETH Zürich spin-off building AI-powered procurement software for the European construction industry. Its platform automates supplier selection, tender management, and bid evaluation, and currently processes more than CHF 8 billion in tender volume for over 110 customers across Switzerland, Austria, and Germany. Scalera is a small, fast-moving team that works closely with users and applies advanced AI techniques to complex, real-world procurement challenges. About the Role Scalera is seeking a Senior Backend Engineer (Python) to build the services, APIs, and data infrastructure powering its AI-driven procurement platform. You will work closely with the CTO and VP of Engineering to integrate AI models into production workflows, process large and complex datasets, and build reliable systems capable of scaling across European markets. The role is well suited to an experienced backend engineer who enjoys solving ambiguous problems, experimenting with new approaches, and taking ownership from initial problem discovery through production delivery. Key Responsibilities Own engineering problems end-to-end, from understanding user needs through solution design and production delivery. Build and maintain Python backend services that integrate AI capabilities into production workflows. Develop AI-powered functionality such as: Document parsing Supplier matching Bid scoring Procurement data processing Design and implement scalable RESTful APIs. Build integrations connecting AI services with frontend applications and external platforms. Develop data pipelines for ingesting, normalizing, and processing large volumes of structured and unstructured construction data. Design backend systems capable of reliably handling complex and data-intensive workloads. Collaborate with engineering teammates through code reviews, testing, and CI/CD. Maintain high standards for code quality, reliability, and maintainability. Evaluate and experiment with emerging AI techniques for real-world procurement challenges. Work closely with product and engineering leadership to identify technical opportunities and solutions. Investigate problems where existing off-the-shelf technologies may not provide an adequate solution. Continuously improve backend architecture, development processes, and engineering practices. Required Qualifications 4+ years of professional backend engineering experience. Strong proficiency in Python as a primary development language. Strong experience designing and implementing RESTful APIs. Production experience with FastAPI or Django. Solid understanding of relational databases, data modeling, and query optimization. Experience with CI/CD pipelines and modern software development practices. Strong focus on code quality, maintainability, and reliability. Ability to work effectively in ambiguous environments and make progress without perfect requirements. Strong ability to scope, prioritize, and independently deliver engineering projects. Genuine interest in AI/ML systems and understanding how AI behaves in production environments. Excellent written and verbal communication skills. Strong collaboration skills and ability to work effectively within a small engineering team. Technical Skills Python FastAPI Django REST APIs Backend Engineering API Design Database Design Data Modeling Query Optimization Data Pipelines CI/CD Automated Testing AI/ML Integration Structured & Unstructured Data Cloud Infrastructure Preferred Qualifications Experience with Google Cloud Platform (GCP). Familiarity with Cloud Run, BigQuery, Pub/Sub, or comparable GCP services. Experience building data-heavy or AI-integrated product architectures. Familiarity with AI developer tools such as Cursor, Claude, or GitHub Copilot. Experience in B2B SaaS environments. Background in construction technology. Knowledge of procurement technology or procurement workflows. German language skills. Experience working in small, rapidly evolving engineering teams. Working at Scalera Work from the company's Zürich headquarters four days per week. Fridays are remote. Small, collaborative engineering team with minimal bureaucracy. Direct collaboration with the CTO and VP Engineering. Opportunity to influence architectural and technology decisions. Competitive salary and equity participation. Opportunity to work on challenging applications of AI in the construction and procurement industry. Why Join Scalera? At Scalera, you won't simply maintain an existing backend platform. You'll help build the infrastructure behind an AI-powered procurement product addressing complex, high-value problems in the European construction industry. The role offers substantial ownership, direct access to technical leadership, and the opportunity to experiment with emerging AI technologies while solving practical problems involving large-scale data, intelligent automation, and enterprise software.