Senior Backend Developer (File Processing)
Payabl
| Company | Payabl |
| Category | Engineering |
| Location | Warsaw |
| Remote | On-site (inferred) |
| Employment | Full-time |
| Level | Senior |
| Salary | Not stated by the employer |
| Posted | 24 Jun 2026 |
| Last verified | 31 Jul 2026 |
| Source | Employer career page (workable) |
Description
The role is about: We are a lean but growing engineering team working in the eCommerce payment processing space. As we expand, we are looking for a Senior Backend Developer to join our File Processing squad and take ownership of our pipeline migration. You will lead the transition from legacy Perl/crontab infrastructure to a modern, observable, and maintainable Python-based architecture. You will play a central role in designing, building, and operating the systems that process daily scheme files (e.g., Visa and Mastercard clearing/settlement files), replacing manual production access patterns with robust orchestration and deployment automation. In this small team, your voice carries real weight—you will help define how we build, not just what we build. Location: Remote from Poland (Contractor arrangement) or Cyprus Onsite (employment arrangement) Reporting to: Technical Lead What you will do: Pipeline Re-architecture: Migrate and re-architect legacy Perl batch jobs and crontab pipelines into modern Python-based services. Workflow Orchestration: Design and implement orchestration using Prefect or Airflow , including alerting, observability dashboards, and safe job re-run capabilities. Modern Observability: Instrument services with structured logging and metrics (CloudWatch, or Grafana) to eliminate the need for direct production server access. Data Layer Ownership: Manage the data layer for file ingestion: landing raw scheme files to S3, parsing/transforming them, and persisting to PostgreSQL or RDS for reconciliation. Financial Domain Logic: Process and reconcile payment scheme files (clearing, settlement, chargebacks) from card schemes and acquirers. Engineering Standards: Contribute to architecture decisions, write technical documentation, and establish best practices across the team. What we need: Python Seniority: 5+ years of production-grade Python expertise. Orchestration Mastery: Proven experience in job orchestration using Prefect or Airflow . AWS Depth: Solid experience with AWS services, specifically S3, Lambda, SQS, and ECS . Data & Databases: Strong experience with relational databases (MySQL/PostgreSQL) and processing large-scale file-based data. Clean & Intentional Code: We value deep engineering logic over AI-generated snippets. You should be a "clean code" advocate who can explain the reasoning behind every line you ship. Curiosity for Product: You care about the "why" behind a feature. You are interested in how a product works for the end-user and the business. English Proficiency: Strong English communication skills—both written and verbal. 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. Hiring Process: Step 1 – Thinking in Action (40 minutes) Your first conversation will be with our Talent Acquisition team. We'll explore your background, career journey, motivations, and overall fit for the role. As part of this discussion, you'll also complete a short technical screening that will be reviewed by our engineering team. This stage helps us understand both your experience and how you approach technical challenges. Step 2 – Build in Production (60–90 minutes) Meet with the Team Lead and technical experts for a practical assessment. Depending on the role, this may involve a live coding exercise or a real-world scenario designed to evaluate your technical skills, problem-solving approach, and ability to work through challenges similar to those faced by our teams. Step 3 – Final Interview (45 minutes) The final stage is a group interview with senior members of our Technology squad, which may include the CTO, CPO, a