Senior Backend Engineer, Python – Core Gateway

payabl.

Senior Backend Developer supporting a Perl payment gateway and leading Python microservices modernization. Collaborating with multi-functional teams to ensure high performance and scalability in a fast-paced environment.

Posted 6/22/2026full-timeVilnius • 🇱🇹 LithuaniaSeniorWebsite

Tech Stack

Tools & technologies

AWSCloudDockerGoKafkaPerlPython

About the role

Key responsibilities & impact

Dual-Track Maintenance: Support and extend the existing Perl-based payment gateway debugging production issues and adding features while the migration is ongoing.
Modernization: Design, develop, and maintain modern server-side components in Python, ensuring high performance and scalability.
Integrations: Integrate third-party APIs and external payment services into both legacy and modern platform layers.
Agile Collaboration: Maintain clean and strong English communication to effectively collaborate with multiple stakeholders across departments working in agile sprints.
Product Thinking: Go beyond the "what" and "how" of the code bring a product-focused mindset to understand the business logic and user impact of what you build.
Engineering Standards: Participate in code reviews, uphold high code quality standards, and contribute to a culture of continuous improvement.
Infrastructure: Work closely with DevOps on CI/CD pipelines, containerization, and cloud deployments.

Requirements

What you’ll need

Python Expertise: 5+ years of backend engineering experience with strong Python mastery (AsyncIO and FastAPI preferred).
Legacy Flexibility: Experience with Perl (or a genuine eagerness to learn and work within Perl production code). We value polyglot engineers who can read and refactor legacy code.
API Mastery: Solid experience integrating third-party APIs and a deep understanding of webhooks, callbacks, and retry policies.
Tech Stack: Experience with CI/CD pipelines (GitLab preferred), Docker containerization, and familiarity with AWS (Lambda, cloud services).
Architecture: Exposure to event-driven architectures (Kafka, message queues, etc.).
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—to collaborate across multi-functional teams.

Benefits

Comp & perks

Grow with Us: Annual Learning Budget for professional development (eligible after probation)—because your growth is our growth.
Celebrate Together: We bring colleagues from all offices together for unforgettable company celebrations.
Global Collaboration & Events: Opportunities to participate in international company events and initiatives, connecting with colleagues from all regions and contributing to a truly global community

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills & Tools

PythonPerlAsyncIOFastAPIAPI integrationCI/CDDockerAWSevent-driven architectureclean code

Soft Skills

communicationcollaborationproduct thinkingcuriositycontinuous improvement