Senior Backend Developer – Services

This is a fully remote position, open to applicants in Poland.

📋 Description

• Legacy Modernization: Analyze legacy code (PHP, Perl, or JavaScript), extract the business logic, and accurately reimplement it within a contemporary microservices architecture.

• Reliability First: Guarantee idempotency, data integrity, and effective error handling across all services — "almost working" is never acceptable.

• Greenfield & Refactoring: Allocate your time between developing new features from the ground up and refactoring existing legacy modules into clean, maintainable code.

• API Engineering: Design and consume external APIs with a comprehensive understanding of webhooks, callbacks, and intricate retry policies.

• Agile Collaboration: Uphold clear and effective English communication to collaborate efficiently with various stakeholders across departments during agile sprints.

• Product Thinking: Move beyond the "what" and "how" of the code — adopt a product-focused mindset to grasp the business logic and end-user implications of your work.

• Infrastructure Contribution: Engage in CI/CD pipelines, Docker, or Kubernetes infrastructure where applicable. If you have a passion for infrastructure, your input is highly valued.

• Innovation: Suggest and champion tools or technologies that can significantly enhance our performance, security, or development speed.

⛳️ Requirements

• Python Mastery: Over 5 years of backend engineering experience with strong proficiency in Python. Deep AsyncIO expertise — you must be adept at developing non-blocking, high-reliability microservices.

• Framework Expertise: Hands-on experience with FastAPI at a production level (beyond mere familiarity).

• Databases: Proficient with MySQL and/or PostgreSQL — including query design, schema comprehension, and migration strategies.

• Testing Discipline: Experience in writing unit and integration tests (pytest preferred).

• API & Reliability Patterns: Proficient in designing and consuming external APIs with a solid understanding of webhooks, callbacks, and intricate retry policies.

• Ownership Mindset: Readiness to take full responsibility for high-traffic, always-on applications and operate autonomously within an established architectural framework.

• Confidence in Complex Systems: Comfortable working in complex distributed environments where reliability is non-negotiable.

• Clean & Intentional Code: We prioritize deep engineering logic over AI-generated snippets. You should be able to articulate the reasoning behind every line of code you deliver.

• Curiosity for Product: You are interested in the "why" behind a feature — understanding its impact on the end-user and its significance for the business.

• Strong English: Proficient in both written and verbal communication to collaborate effectively across multi-functional teams.

• Nice to Have: Familiarity with PHP, Perl, or JavaScript — a valuable asset for legacy understanding.

• Experience with Kafka / Redis.

• Familiarity with Docker / CI/CD / Kubernetes.

• Exposure to the financial industry — fintech, payments, 3DS, Token Management Systems, or payment gateway integrations.

• Proven track record of successfully migrating systems from one language or paradigm to another.

🏝️ Benefits

• Grow with Us: Annual Learning Budget for professional development (available after probation)—your growth is our growth.

• Celebrate Together: We unite colleagues from all offices for memorable company celebrations.

• Global Collaboration & Events: Opportunities to engage in international company events and initiatives, connecting with colleagues from all regions and contributing to a truly global community.