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, Chat GPT) 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), Postgre SQL, Kafka, Data Dog
On‑call and incident response experience
Understanding of the Mexican fintech ecosystem (BNPL, credit, regulation)
Our Stack
Java (primary), Python, Go
AWS (ECS, Lambda)
Postgre SQL
Kafka
Data Dog
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.

📌 Sr. backend engineer (Ciudad de México)
🏢 Aplazo
📍 Ciudad de México