Senior Python Engineer (Skycash)

About Skycash
SkyCash is one of Poland's leading mobile payment platforms, trusted by millions of users across the country. Founded and headquartered in Warsaw, SkyCash enables fast, secure, and seamless digital payments — from public transport and parking to bills and online services. With a team of 25 passionate engineers and product specialists, SkyCash combines startup agility with the scale and reliability of a platform that millions rely on every day.

About the role
We are seeking a skilled and motivated Python Developer with a passion for building robust and scalable backend systems. In this role, you will be responsible for designing, developing, and maintaining high-performance APIs and infrastructure capable of supporting real-time interactions and large-scale user activity.
You will play a key role in ensuring the reliability, efficiency, and maintainability of backend components across our platform. The ideal candidate has a strong command of Python and modern frameworks, along with a deep commitment to writing clean, secure, and production-ready code that performs under heavy load.
We work AI-natively: the ideal candidate uses AI coding agents and assistants as a core part of their daily development workflow to move quickly from idea to production-ready code without compromising on quality, security, or maintainability.

📍 Location: Warsaw, Poland - onsite (office-based role)

Key Responsibilities:

• Build and maintain scalable, reliable, and secure backend services using Python
• Design and implement robust RESTful and GraphQL APIs to support mobile and front-end apps
• Collaborate with front-end and mobile teams (iOS/Android) to integrate APIs and optimize user experience
• Ensure back-end services can scale to handle high concurrency and large user bases
• Work with asynchronous frameworks for real-time features and background task processing
• Design efficient data models and manage SQL and NoSQL databases
• Use CI/CD and containerization tools (Docker, Kubernetes) to streamline deployment pipelines
• Use AI coding agents and assistants (e.g., Claude Code, Cursor, GitHub Copilot) throughout the development lifecycle — design, implementation, testing, code review, and documentation — while retaining full ownership of correctness and security
• Write clean, testable, and well-documented code

Qualifications & Experience:

• 5+ years of experience in Python development, with focus on RESTful and asynchronous APIs
• Deep understanding of application architectures, including client-server communication patterns
• Hands-on experience with backend frameworks such as FastAPI or Flask, emphasizing performance and modular design
• Skilled in designing APIs optimized for mobile performance and low-latency environments
• Experience with major cloud platforms, including serverless components (e.g., Lambda, Cloud Functions…)
• Experience collaborating in Agile development teams, participating in sprint planning, code reviews, and iterative delivery cycles
• Experience working with CI/CD pipelines and Git workflows, with a strong focus on writing automated tests to ensure code quality
• Demonstrated fluency in AI-assisted development: able to direct coding agents effectively, break work into tasks they can execute, iterate quickly on their output, and critically validate generated code rather than accept it blindly
• Familiarity with system monitoring and alerting using tools like Prometheus, Sentry, or ELK
• Experience with relational, NoSQL, and in-memory data stores for scalable data handling
• Degree in Computer Science or related field, or equivalent hands-on experience
• Proven track record in delivering production-ready, high-scale, mobile-connected backend systems

Preferred Qualifications:

• Experience collaborating with mobile teams using React Native, Flutter, or native iOS/Android platforms
• Familiarity with real-time data handling through WebSockets, MQTT, or other streaming protocols
• Background in developing and supporting multi-tenant, internationalized, or localized mobile applications
• Understanding of mobile analytics, user behavior tracking, and integration with tools like Firebase Analytics or Mixpanel
• Experience with agentic development workflows — delegating multi-step tasks to coding agents, AI-assisted refactoring and test generation, and using agents for codebase exploration and debugging
• Hands-on experience with open-source technologies / active participation in open-source communities or contributions to public projects

What's in it for you?

• Working for the customer directly, ownership culture;
• 20 fully paid business days of vacation;
• 15 fully paid sick leaves;
• Public holidays;
• Compensation for health insurance and sports club membership (after trial period).

Apply and Join Us Today! ✨