Sr. Backend Engineer

Sr. Backend Engineer ABOUT THE ROLE We're looking for a Senior Backend Engineer to independently own features and deliver high-quality backend systems. You'll take projects from spec to production, write code that others want to work with, and help mentor newer engineers. At this level, you're a reliable, autonomous contributor—you can scope and ship features end-to-end with minimal guidance and proactively unblock yourself and others. WHAT YOU'LL DO - Own features end-to-end — Scope, design, build, test, and ship features independently - Write quality code — Deliver clean, testable, well-documented code with strong testing discipline - Unblock the team — Proactively help teammates debug issues and remove blockers - Handle on-call — Confidently respond to incidents using observability tools - Mentor newer engineers — Support E1s through pairing, onboarding, and code review - Leverage AI daily — Use AI tools to accelerate coding, debugging, testing, and learning - Pay down tech debt — Identify and fix issues that slow the team down WHAT WE'RE LOOKING FOR Technical - 3+ years building backend systems - Strong experience with Java (Python/Go a plus) - Good understanding of distributed systems, APIs, and cloud infrastructure - Strong testing discipline—unit tests, integration tests, edge cases - Systematic debugging skills across service boundaries AI Fluency - Uses AI tools (Copilot, Claude, ChatGPT) daily for coding, debugging, and test generation - Builds reusable prompts or workflows that help the team - Teaches effective AI usage to junior engineers - Curious about new AI capabilities relevant to backend development Communication - Writes clear design docs and runs small design discussions - Gives and receives direct, timely feedback - Fluent in Spanish; working knowledge of English for cross-team collaboration Mindset - Self-directed; you don't wait to be told what to do - Comfortable with ambiguity and changing requirements - Product-minded—you care about business outcomes, not just code NICE TO HAVE - Experience in fintech, payments, or lending - Familiarity with our stack: AWS (ECS, Lambda), PostgreSQL, Kafka, DataDog - On-call and incident response experience - Understanding of the Mexican fintech ecosystem (BNPL, credit, regulation) OUR STACK Java (primary), Python, Go · AWS (ECS, Lambda) · PostgreSQL · Kafka · DataDog · Pulumi · Jenkins WHY APLAZO Our mission is to empower financial access and opportunity across Latin America through fair, simple, and transparent solutions. Our tech vision: be the most beloved and innovative tech organization in Latin America. We're a Series B fintech growing fast—you'll have real ownership, impact, and the chance to shape how millions of people access credit.