Senior/Principal Full Stack Developer (Python + JavaScript/Typescript)

Are you a seasoned developer ready to work on cutting-edge financial technology? We are looking for a Senior/Principal Full Stack Developer to join an ambitious global SaaS project in the finance domain. You will be part of a team building and optimizing mission-critical payment processing systems used by businesses worldwide.
At Sigma Software, we value innovation, technical excellence, and collaboration. This role offers the opportunity to work with modern technologies across both backend and frontend, contributing to a platform that is reshaping revenue operations. Join us and enjoy working in an environment that supports professional growth, knowledge sharing, and impactful projects.
CUSTOMER
Our customer is a global SaaS company specializing in AI-native revenue platforms for modern finance and accounting teams.
PROJECT
Their solutions streamline subscription management, billing, and revenue operations for businesses of various sizes. The company is recognized for its innovation in automating complex financial workflows, integrating with leading payment gateways, and ensuring compliance with industry standards.
Design, develop, and maintain backend and frontend components for the revenue platform
Build and optimize APIs, services, and integrations to ensure performance, scalability, and reliability
Collaborate with cross-functional teams to define requirements, design solutions, and deliver features
Contribute to backend development (Python) and frontend development (TypeScript/JavaScript)
Participate in architectural planning and technical decision-making
Ensure code quality through best practices, reviews, and testing
Troubleshoot and resolve technical issues across the stack
Mentor team members and share knowledge to enhance team capability
5+ years of professional software development experience, with a strong focus on Python
Proficiency in JavaScript and TypeScript
Hands-on experience with FastAPI and Temporal (or similar workflow orchestration tools)
Solid understanding of backend architecture, API design, and microservices
Experience integrating frontend and backend components in a full stack environment
Strong problem-solving skills and ability to work independently on complex tasks
Familiarity with cloud environments (AWS, GCP, or Azure) and CI/CD pipelines
Excellent communication skills and ability to collaborate effectively in a distributed team
Upper-Intermediate level of English