Backend Staff Engineer

About DEUNA 🧡 DEUNA is a rapidly growing startup revolutionizing global commerce with ATHIA, our AI-powered orchestration and payments platform that helps large enterprises boost approval rates, reduce costs, and unlock new revenue. Built by the team behind DEUNA—the fastest-growing Commerce OS in Latin America—ATHIA combines payment intelligence, checkout optimization, and data orchestration in one powerful solution. With deep integrations across 300+ PSPs and alternative payment methods, and over 20% of Mexico’s digital economy running through our platform, we simplify global payments through a single integration and centralized reconciliation. We are a rapidly growing startup expanding into the U.S. to meet the urgent needs of large retailers, marketplaces, airlines, and QSRs. Join us to shape the future of payments! 🚀 Visit https://www.deuna.com/ to learn more about us! Role Overview We are seeking a Backend Staff Engineer to act as a deep technical expert and architectural leader across backend systems. This role is focused on solving highly complex engineering challenges, scaling distributed systems, and setting backend engineering standards across the organization. This is not a management role. Instead, you will serve as a technical authority, partnering with Engineering Managers while owning the technical depth and backend architecture decisions. You will work in a dynamic startup environment, where backend systems directly power mission-critical product capabilities. Key Responsibilities Backend Architecture & System Design - Design and evolve scalable, secure, and resilient backend systems. - Architect high-availability APIs and distributed services. - Define best practices for reliability, observability, and performance. Deep Technical Contribution - Write high-quality, production-grade backend code. - Lead refactoring efforts and performance improvements. - Identify system bottlenecks and implement scalable solutions. - Design data models, caching strategies, and asynchronous workflows. Technical Influence - Provide technical direction across teams. - Lead complex design discussions and evaluate trade-offs. - Improve backend development standards and documentation practices. Scalability & Reliability - Design systems capable of handling high-traffic and transaction-heavy workloads. - Define strategies for load balancing, scaling, monitoring, and failure handling. - Improve system instrumentation and observability. Requirements - Extensive experience as a Senior Backend Engineer, Principal Engineer, or Staff Engineer. - Strong backend expertise in: Golang and/or Python - Deep experience with: Distributed systems API design (REST/GraphQL) Event-driven architectures - Strong knowledge of: Data structures and algorithms System design and performance optimization Design patterns - Experience with AWS and cloud-native infrastructure. - Strong knowledge of relational and non-relational databases. - Experience with caching (e.g., Redis) and messaging systems. - Strong understanding of security best practices. - Excellent communication skills. Native or fluent English. Spanish is a plus. Nice to Have - Experience in payments, fintech, or financial infrastructure. - Experience designing transaction processing systems. - Familiarity with fraud prevention, payment orchestration, or financial compliance systems.