Senior Backend Developer (File Processing)

We're powering the growth of merchants by helping them take payments easily, securely and globally.

• 5+ years of production-grade Python expertise.
• Proven experience in job orchestration using Prefect or Airflow.
• Solid experience with AWS services, specifically S3, Lambda, SQS, and ECS.
• Strong experience with relational databases (MySQL/PostgreSQL) and processing large-scale file-based data.
• Advocate for clean, intentional code with the ability to explain the reasoning behind every line.
• Strong English communication skills, both written and verbal.
• Curiosity about product functionality and business impact.

Nice to Have:

• Familiarity with payment scheme file formats (Visa BASE II, Mastercard IPM, or equivalent).
• Experience reading and refactoring Perl or legacy scripting languages.
• Knowledge of payment clearing, interchange, and reconciliation processes.

• Migrate and re-architect legacy Perl batch jobs and crontab pipelines into modern Python-based services.
• Design and implement workflow orchestration using Prefect or Airflow, including alerting, observability dashboards, and safe job re-run capabilities.
• Instrument services with structured logging and metrics (CloudWatch or Grafana) to eliminate direct production server access.
• Manage the data layer for file ingestion: landing raw scheme files to S3, parsing/transforming them, and persisting to PostgreSQL or RDS for reconciliation.
• Process and reconcile payment scheme files (clearing, settlement, chargebacks) from card schemes and acquirers.
• Contribute to architecture decisions, write technical documentation, and establish best practices across the team.

Location: Remote from Poland (Contractor arrangement) or Cyprus Onsite (employment arrangement).