Senior Backend Engineer

About the role

Shalion, a data and insights company serving e-commerce brands through Digital Shelf Optimization, Retail Media and Food Service Aggregators solutions, is looking for a Senior Backend Engineer to lead the backend of its products. The role sits alongside the internal software team and is product-oriented: you define the technical roadmap, decide on technologies and bring AI and automation into client-facing workflows. You will manage one engineer from day one, with the team potentially growing later.

Key responsibilities

• Lead back-end development across the products and own the engineering roadmap for new features.
• Decide on and evolve the technology stack, including trade-offs such as rebuilding versus patching.
• Manage the existing backend engineer while staying hands on in the work.
• Develop new technical solutions for products still on the roadmap.
• Introduce AI and automation into the products to speed up delivery.
• Set up engineering frameworks, standards and processes across the product portfolio.
• Work closely with product stakeholders and the CEO to turn their needs into a technical roadmap.

Required profile

• 5+ years of hands-on back-end experience, ideally across multiple products, including at least 1 year in a management capacity.
• Comfortable making and owning technology stack decisions.
• Experience building engineering processes and team structure from the ground up.
• Genuine interest in applying AI and automation to product development.
• Professional fluency in English and Spanish, both required.
• Nice to have: experience scaling an engineering team, prior multi-product experience, AI-powered workflow automation experience, and frontend knowledge.

Required skills

• Current stack includes Kotlin, Python, React, Langgraph, AWS and Snowflake; choosing the next stack is part of the job.
• Backend engineering and engineering leadership.

What we offer

• Permanent contract, salary from 50,000 to 60,000 EUR gross per year depending on experience.
• Hybrid model: 3 days in office, 2 days remote, in the Sarrià-Sant Gervasi district of Barcelona.
• Flexible benefits: pre-tax allocation of part of gross salary to meal vouchers, transport allowance and private healthcare.
• Office perks such as fresh fruit and specialty coffee daily.