Sr. Backend Engineer (Xico)

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

Language

• 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.