Fullstack 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 to learn more about us! ## **Role Overview** We are looking for a **Staff Software Engineer – Fullstack** to act as a senior technical leader across our engineering organization. This is a **high-impact individual contributor role**, focused on driving architecture, setting technical direction, and solving complex, cross-team challenges. You will partner closely with Engineering, Product, and leadership to ensure our systems scale reliably as the business grows. This role is not focused on people management — instead, you will operate as a **technical authority and multiplier**, influencing multiple teams and raising the overall engineering bar. --- ## **What You’ll Do** ### **Technical Leadership & Architecture** - Own and evolve the architecture of critical fullstack systems across frontend and backend. - Lead the design of scalable, high-performance, and resilient distributed systems. - Set and uphold engineering standards, best practices, and design principles. - Drive alignment across teams on architectural decisions and technical direction. ### **Hands-On Engineering** - Contribute to high-impact areas of the codebase. - Write clean, maintainable, production-grade code. - Lead complex refactors and performance optimization efforts. - Conduct in-depth code reviews and mentor engineers through technical guidance. ### **Cross-Team Impact** - Partner with Product and Engineering leaders to evaluate trade-offs across scalability, performance, cost, and security. - Design APIs, data models, and system interactions that support long-term growth. - Guide teams on handling edge cases, failure scenarios, and observability. ### **Technical Strategy & Innovation** - Identify system bottlenecks and drive scalable solutions. - Influence long-term technical strategy and roadmap. - Evaluate and introduce new technologies where they add meaningful value. - Improve monitoring, instrumentation, and system reliability practices. --- ## **What We’re Looking For** - Proven experience as a **Staff, Principal, or Senior Software Engineer** in fullstack environments. - Strong frontend expertise with: - **React** - **Next.js** - **TypeScript** - Strong backend experience with: - **Golang and/or Python** - Deep experience designing **distributed systems and scalable APIs**. - Strong fundamentals in: - Data structures and algorithms - System design and architecture - Design patterns and trade-offs - Hands-on experience with **AWS and cloud-native architectures**. - Experience with **SQL and NoSQL databases**. - Strong debugging, performance optimization, and refactoring skills. - Excellent communication skills, with the ability to influence technical decisions. - **Fluent or native English** (Spanish is a plus). --- ## **Nice to Have** - Experience in **payments, fintech, e-commerce, or transaction-heavy platforms**. - Experience building **high-availability, low-latency systems**. - Familiarity with **regulated environments** (PCI-DSS, financial systems, etc.).