Join a project where scalable backend engineering meets modern AI-driven financial technology. We are looking for a Senior / Principal Python Engineer to help build and evolve high-load payment and revenue systems used by businesses worldwide.
You will work on cloud-native backend services, distributed systems, and payment infrastructure while collaborating with Product, Frontend, AI, and Engineering teams. This role is ideal for engineers who enjoy solving complex technical challenges, influencing architecture decisions, and driving engineering excellence.
We at Sigma Software value technical ownership, collaboration, and continuous learning. You will join an international environment where innovation, modern technologies, and professional growth are part of everyday work.
CUSTOMER
Our Customer is a global SaaS company developing an AI-native revenue platform for modern finance and accounting teams. The company provides subscription management, billing automation, and revenue operations solutions that help organizations optimize financial workflows, improve scalability, and streamline transaction management across complex business ecosystems.
Job Description- Design, develop, and maintain scalable backend services and APIs for cloud-native applications
- Build and optimize distributed systems, payment processing pipelines, and backend infrastructure
- Ensure high availability, security, scalability, and performance of backend systems
- Participate in architecture discussions and contribute to technical strategy and decision-making
- Collaborate with Product, Frontend, AI, and DevOps teams to deliver high-quality solutions
- Mentor engineers through code reviews, technical guidance, and engineering best practices
- Troubleshoot complex production issues and drive continuous improvements
- Contribute to AI-powered product capabilities and AI/ML-driven initiatives
- Promote engineering excellence, observability, and maintainability across services and infrastructure
- 5+ years of professional Back-end software engineering experience using Python
- Solid experience designing and building RESTful APIs and distributed backend systems
- Strong knowledge of SQL and/or NoSQL databases
- Hands-on experience with AWS cloud services
- Experience with Docker and Kubernetes
- Understanding of scalable cloud-native architectures and microservices principles
- Experience working in cross-functional Agile teams
- Strong problem-solving, communication, and collaboration skills
- Ability to drive technical initiatives and contribute to architectural decisions
- Upper-Intermediate or higher English level
WILL BE A PLUS
- Experience with FastAPI and TypeScript
- Experience building AI-powered user experiences or integrating AI/LLM services into Front-end applications
- Hands-on experience with AI technologies and LLM ecosystems
- Experience integrating OpenAI, Anthropic, or similar AI services
- Experience working with AI SDKs and prompt-based applications
PERSONAL PROFILE
- Proactive and ownership-driven mindset
- Strong analytical and systems-thinking approach
- Ability to work effectively in a collaborative international environment
Skills Required
- 5+ years of professional Back-end software engineering experience using Python
- Designing and building RESTful APIs and distributed backend systems
- Strong knowledge of SQL and/or NoSQL databases
- Hands-on experience with AWS cloud services
- Experience with Docker and Kubernetes
- Understanding of scalable cloud-native architectures and microservices principles
- Experience working in cross-functional Agile teams
- Strong problem-solving, communication, and collaboration skills
- Ability to drive technical initiatives and contribute to architectural decisions
- Upper-Intermediate or higher English level
- Experience with FastAPI and TypeScript
- Experience integrating OpenAI, Anthropic, or similar AI services / working with LLM ecosystems
What We Do
Sigma Software Group, an award-winning and trusted IT partner, has been serving customers for over 21 years, providing comprehensive IT solutions to various businesses, ranging from startups to established software product houses. As one of Europe's substantial IT consultancies, it brings together a dedicated workforce of over 2,100 professionals in 40 offices across 19 countries. With a diverse client base, including more than 300 enterprises, including Fortune 500 stalwarts, Sigma Software Group is a preferred choice for developing solutions that help businesses create cutting-edge products while meeting their unique needs. Sigma Software Group operates as a dynamic ecosystem of tech companies, offering 25 ready-to-implement innovative products and 40+ value-added services. Furthermore, Sigma Software Group is committed to fostering innovation through initiatives such as the Sigma Software Labs business incubator, Sigma Software University, the SID Venture Partners VC Fund, UA Tech Network, Techosystem, the European Business Association, and other collaborative efforts. Since 2015, Sigma Software Group has consistently earned recognition on the IAOP's prestigious World's Top 100 Outsourcing list. The company's accomplishments have also been acknowledged by prominent global media outlets such as Forbes, CNBC, The Times, and Reuters
