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NDA, Mobile Payment Platform | Senior Python Backend Developer

SD Solutions
Full-time
On-site
Warsaw, Poland
Backend Development

On behalf of NDA, Mobile Payment Platform, SD Solutions is looking for a talented Senior Python Backend Developer.

We are seeking a Senior Python Developer with a passion for building robust, scalable systems that support high-concurrency, real-time mobile applications. In this role, you’ll join a small, empowered team responsible for designing and implementing the core backend services that power the NDA platform.
This is a rare opportunity to be part of an end-to-end rebuild of a nationally trusted service — using modern tools, architecture, and development practices from day one.

SD Solutions is a staffing company operating globally. Contact us to get more details about the benefits we offer.

Responsibilities:

  • Design and develop scalable backend services using Python and modern frameworks (e.g. FastAPI)
  • Build and maintain RESTful and GraphQL APIs to support SkyCash’s iOS, Android, and web applications
  • Collaborate closely with mobile and front-end teams to ensure seamless integration and optimal performance
  • Build real-time features using asynchronous programming (e.g. asyncio)
  • Work with SQL and NoSQL databases to store and process large volumes of transactional data
  • Ensure reliability and performance under high user load and concurrency
  • Implement CI/CD pipelines using tools like GitHub Actions, Docker, and Kubernetes
  • Write clean, testable, and maintainable code following modern development best practices
  • Take ownership of features, including testing and production readiness
  • Leverage AI tools where appropriate to optimize workflows and productivity

Requirements:

  • A backend engineer with 5+ years of experience, especially in designing high-scale mobile-connected APIs
  • Skilled in Python, asynchronous programming, and frameworks like FastAPI, Flask, or similar
  • Comfortable with real-time communication technologies such as WebSockets
  • Strong understanding of client-server architecture and API design principles
  • Familiar with both SQL and NoSQL databases (DynamoDB experience is a plus)
  • Experience with cloud platforms (AWS, GCP, or Azure) and serverless architecture
  • Proficient in containerization (Docker) and deployment via CI/CD pipelines
  • Advocates for code quality, including writing unit/integration tests and automated pipelines
  • Motivated, responsible, and proactive – you own your work from start to finish
  • Comfortable working in a fast-paced, flexible environment with small, autonomous teams
  • Open to working 3 days/week onsite at our Polish office

Advantages:

  • Experience working in or migrating from Java-based systems
  • Familiarity with mobile analytics tools like Firebase, Mixpanel, etc.
  • Experience collaborating with mobile developers (native or React Native/Flutter)
  • Understanding of monitoring tools (Prometheus, Sentry, ELK)
  • Contributions to open-source projects or active participation in developer communities

About the company:

NDA, Mobile Payment Platform is one of Poland’s leading mobile payment platforms, enabling millions of users to purchase public transportation tickets, pay for parking, top up phones, and more – all from a single, intuitive app.
As we undergo a significant technological transformation, we’re rebuilding our platform from the ground up to enable speed, flexibility, and innovation. We're replacing legacy systems with a scalable Python-based architecture and integrating real-time and AI-driven components to deliver a best-in-class digital mobility experience.

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