Senior Backend Engineer – AI Agents

About seQura

seQura provides innovative, flexible, and easy-to-use payment technologies that help merchants acquire, convert, and retain more customers. We make a difference in sales performance by tailoring our solutions to different sectors—Retail, Education, Eyewear, Repairs, and Travel—to address unique pain points and deliver superior results.

We empower smart shopping for consumers who seek more value, convenience, and flexibility, offering new payment experiences that let them save, access interest‑free credit, or pay in small, comfortable installments of up to 24 months.

Born in Barcelona, seQura is a privately‑owned fintech, currently expanding across Southern Europe and Latin America, growing above 50% CAGR and approaching €100M in Annual Recurring Revenue. Over 5,000 businesses, nearly 2 million shoppers, and almost 400 employees continue to rate us as one of the most loved and trusted fintechs, with an NPS of 87%, a Trustpilot rating of 4.7/5, and a Glassdoor rating of 4.7/5.

We are building seQura’s Smart Agent platform, an intelligent agent system that guides shoppers before, during, and after their purchases. The platform relies on LLMs for human‑like interaction, combined with retrieval‑augmented generation (RAG) over SeQura’s data, crawling, and structured product/taxonomy information.

This role does not require AI research, data science, or mathematical modeling—all AI/LLM frameworks are already in place. What matters is building solid, production‑grade backend systems that allow these agents to reason over shopper needs safely and effectively.

• Build robust, scalable backend systems for agent workflows, handling context, state, and interactions.
• Integrate AI agent capabilities with core platforms (payments, shopper accounts, risk, merchant services) safely and efficiently.
• Use RAG frameworks and structured data to provide intelligent responses, without fine‑tuning models.
• Collaborate with Product, Frontend, Data, and AI teams to design systems and shape the shopper experience.

• Design and build the backend foundations of seQura’s Smart Agent platform to assist shoppers throughout the purchase lifecycle.
• Transform ambiguous product ideas and shopper needs into reliable, scalable backend services.
• Orchestrate agent workflows across multiple services, managing context, state, and interactions.
• Integrate intelligent agent capabilities with core platforms safely and efficiently.
• Contribute to architectural decisions with clarity and simplicity in mind.
• Collaborate effectively with cross‑functional teams, driving alignment and shared ownership.
• Monitor, optimise, and improve production systems, ensuring high performance, availability, and reliability.

• The Smart Agent platform operates at scale, handling complex shopper interactions with reliability and speed.
• Agents consistently find and act on the right context to guide shoppers effectively.
• Backend systems are robust, maintainable, and integrated seamlessly with core services.
• Strong collaboration across Product, AI, and Engineering teams, with clear ownership and accountability.

Must-have:

• 5+ years of experience as a Backend Engineer.
• Experience in production‑grade backend systems (Ruby on Rails preferred; Python, Kotlin, Java, Elixir, or JS also valued).
• Strong knowledge of OOP, clean coding, TDD, and agile principles.
• Experience with agentic systems or LLM‑powered agents (RAG, workflow orchestration, chatbots).
• English proficiency (Spanish nice to have).
• Attitude, ownership, and pragmatic mindset—able to build backend systems that support AI agents without needing DS skills.

Nice‑to‑have:

• Located in Barcelona or willing to relocate.
• Experience scaling backend services to high concurrency and low latency.

Deal‑breakers:

• Pure feature delivery mindset without strategic/platform thinking.
• Weak stakeholder management or low autonomy.
• Not data‑driven.

• Secure, reliable, and supportive workplace with freedom to contribute your best.
• Fellowship and supportive culture fostering a sense of belonging.
• Challenging projects to grow your skills and knowledge.
• Unique, inspiring…