Senior Backend Python Developer - Immediate Hiring

Description

Job Summary: A Colombian fintech is seeking a Senior Backend Python Developer with strong technical judgment to design financial APIs, integrate with critical services, and mentor junior developers. Key Highlights: 1. Design scalable and robust REST APIs for the financial sector 2. Make architectural decisions and mentor junior developers 3. Collaborate with cross-functional teams on a modern tech stack SENIOR BACKEND DEVELOPER · PYTHON · ALÓ CREDIT A rapidly expanding Colombian fintech APIs that process credit in real time. Integrations with Datacrédito, payment gateways, and financial operators. If building the backbone of a growing fintech excites you, keep reading. WHO WE ARE Aló Credit is a Colombian fintech expanding across LATAM. We finance smartphones under the “Buy Now, Pay Later” model. Our backend processes credit applications, verifies bureau data, calculates scoring, executes payments, and manages portfolios for thousands of customers. And our engineering team continues to grow. THE CHALLENGE We need a Senior Backend Python Developer with genuine technical judgment—not just someone to write CRUD operations or repetitive endpoints. You’ll design APIs capable of handling regulated financial production environments, integrate with critical external services, make architectural decisions, and mentor more junior developers. WHAT YOU’LL DO DAILY Design REST APIs using FastAPI and Django microservices—scalable, async when appropriate, sync when required. Model relational data using PostgreSQL as the primary database engine. Perform safe migrations. Write optimized queries. Make well-considered schema decisions. Integrate with external services: payment gateways, credit bureaus (Datacrédito, TransUnion), and financial operators. Handle idempotency, retries, timeouts, and fallback mechanisms. Deploy on AWS EC2, S3, RDS, and Lambda. Build infrastructure that scales. Optimize costs. Real observability. Containerize and automate everything with Docker. Implement CI/CD pipelines. Enable zero-downtime deployments. One-click rollback. Secure APIs using OAuth 2.0, JWT, rate limiting, and strict validation. Financial backend = healthy paranoia about security. Code reviews and architecture discussions Your technical opinion matters in team decisions. Mentor junior developers. Define standards. Collaborate cross-team with Frontend (Angular), Mobile, and QA teams. Your API is the contract between all teams. WHAT YOU NEED TO BRING Bachelor’s degree in Systems Engineering, Software Engineering, Computer Science, Information Technology, or related fields. Postgraduate studies or certifications are a plus. 4+ years of backend development experience specifically with PYTHON (not total years of experience—only years focused on Python backend development). Proven expertise in both FastAPI AND Django—not just one—on real, production-grade projects. Advanced ORM usage (SQLAlchemy and/or Django ORM). You know how to optimize queries, manage migrations, and understand N+1 problems. PostgreSQL as the primary database engine. MySQL experience is also a plus. You’ve designed non-trivial schemas in production. Docker is mandatory. You can containerize services and debug issues inside containers. Production-grade CI/CD. GitHub Actions, GitLab CI, Jenkins, or similar. Your code deploys automatically only after passing tests. AWS: EC2, S3, RDS minimum. Lambda is a bonus. You’ve deployed real services—not just experimented with the console. OAuth 2.0 and JWT: real implementation experience—not just familiarity. Technical English (reading/writing) for documentation, code reviews, and libraries. STRONG PLUS IF YOU HAVE Experience in fintech, banking, or mass consumer sectors (integrations with credit bureaus, payment gateways, regulated financial processes) Celery, Redis, or queue-based systems in production Terraform or infrastructure-as-code Kubernetes (for future larger-scale services) Observability tools (Datadog, New Relic, Sentry, Prometheus) WHAT WE OFFER Salary: $8,000,000 COP Contract: Indefinite term + Statutory benefits Bi-weekly payments LATAM-expanding fintech Senior technical role with voice in architecture Collaborative engineering team Modern tech stack (no legacy code) Real technical decision-making (not just execution) OPERATIONAL DETAILS Bogotá · 100% On-site Monday–Friday 8:30 AM – 5:30 PM Saturdays 8:30 AM – 1:00 PM Work with Frontend (Angular), Mobile, and QA teams ARE YOU THE ONE? If designing real financial APIs excites you, if you’re passionate about technical detail in integrations, if you want to make architectural decisions and mentor other developers, and if you’re willing to work on-site six days a week for this technical challenge—apply now. By applying, you authorize Aló Credit to contact you via WhatsApp to update you on your application status.-Requirements- Minimum education: Postgraduate / Specialization 5 years of experience Keywords: senior, sr