Senior Python Backend Engineer, Financial Systems

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Python Backend Engineer, Financial Systems based in Brazil.

This is a fully remote engineering role focused on building the financial infrastructure behind a modern, AI-powered SaaS platform. You will work on production-grade Python services, financial workflows, APIs, integrations, and multi-tenant systems where reliability and data accuracy are critical. The role combines backend engineering with hands-on development of AI agents, orchestration services, and MCP servers. You will help build systems for payments, billing, payouts, commissions, refunds, reconciliation, and settlement processes. You will also contribute to scalable rules engines and configuration systems that allow customers to launch new products without extensive custom development. The environment is highly autonomous, technically ambitious, and deeply focused on AI-assisted engineering and developer productivity. This is a long-term independent contractor opportunity for candidates located in Brazil or Argentina, with English required for the application.

Accountabilities:: Build and deploy production-grade Python services, AI agents, and MCP servers supporting complex platform workflows, including tool orchestration, context management, and model routing.

Develop and maintain the integration backbone connecting payments, identity, e-signature, real-time data, and other critical third-party services.

Design and evolve rules engines and configuration runtimes that enable customers to create and launch new products with minimal engineering intervention.

Develop migration and data-import systems capable of moving entire companies onto the platform while maintaining data integrity and supporting zero-loss requirements.

Build and scale multi-tenant batch-processing systems handling financially critical workloads, including settlement runs, document pipelines, reconciliation processes, and asynchronous workers.

Design and maintain public APIs that serve the broader customer ecosystem, ensuring reliable contracts and supporting AI agents as first-class API consumers.

Develop and maintain financial systems covering billing, payouts, commissions, refunds, and other transaction and accounting workflows.

Build reliable services capable of operating at the latency and scale required for live financial decisions and high-volume processing.

Apply agentic AI coding tools deliberately throughout the development lifecycle to accelerate implementation, testing, debugging, architecture, and delivery.

Contribute to the evolution of engineering practices, including AI-assisted development, automated testing, specification-driven development, and multi-agent workflows.

Collaborate effectively across technical and product contexts while maintaining high standards for system reliability, security, scalability, and financial accuracy.

Requirements:

Bachelor’s degree or higher in Computer Science or a related technical discipline.

5+ years of professional experience developing web applications and backend systems with Python, particularly in financial systems or financial modules.

3+ years of experience working with SQL databases such as MySQL or PostgreSQL, including data modeling and complex data processing.

3+ years of experience developing SaaS products and cloud-based solutions.

3+ years of hands-on experience with Django or another modern Python web framework.

2+ years of proven experience building and consuming APIs supporting financial transactions.

Advanced mathematical capabilities relevant to financial modeling, algorithms, data processing, and transaction systems.

Professional experience with Docker and AWS-based cloud environments.

Hands-on familiarity with frontend technologies such as React or Vue.js.

Daily, intentional use of agentic AI development tools such as Claude, Cursor, or Codex.

Demonstrated ability to direct AI agents through complex, multi-file, long-horizon engineering tasks.

Strong understanding of backend architecture, API design, distributed systems, and production SaaS environments.

Excellent written and verbal communication skills, with the ability to collaborate effectively in a fully remote environment.

Experience working in a scaling startup, fintech or financial services environment is a strong advantage.

Experience with specification-driven development, AI-generated testing, scaffolding, or architecture is desirable.

Experience building production AI agents or multi-step LLM workflows using LangChain, LangGraph, or equivalent orchestration frameworks is a plus.

Familiarity with multi-agent development workflows, including Agent Teams, parallel agent orchestration, or comparable approaches, is advantageous.

Benefits:

Fully remote position for candidates located in Brazil or Argentina.

Long-term independent contractor engagement.

Opportunity to work at the forefront of AI-assisted software engineering.

Hands-on exposure to modern AI development tools and agentic workflows, including Claude, Codex, Cursor, Copilot, LangChain, LangGraph, LangFuse, OpenRouter, and FastMCP.

Work on complex financial infrastructure where reliability, scalability, and data accuracy directly impact real-world transactions.

Opportunity to build production AI agents and intelligent systems rather than working solely on experimental prototypes.

High-autonomy engineering environment with significant ownership over architecture, implementation, and technical outcomes.

Exposure to a modern technology stack including Python, MySQL, AWS, and cloud-native SaaS infrastructure.

Opportunity to contribute to a rapidly evolving engineering culture centered on AI-driven productivity and continuous innovation.

Collaborative environment focused on community, integrity, resilience, and measurable impact.

How Jobgether works: We use an AI-powered matching process to ensure your application is reviewed quickly, objectively, and fairly against the role's core requirements. Our system identifies the top-fitting candidates, and this shortlist is then shared directly with the hiring company. The final decision and next steps (interviews, assessments) are managed by their internal team. We appreciate your interest and wish you the best!  Why Apply Through Jobgether?    Data Privacy Notice: By submitting your application, you acknowledge that Jobgether will process your personal data to evaluate your candidacy and share relevant information with the hiring employer. This processing is based on legitimate interest and pre-contractual measures under applicable data protection laws (including GDPR). You may exercise your rights (access, rectification, erasure, objection) at any time.     #LI-CL1