Senior Software Engineer (Billing and Payments)

Qdrant is a fully remote cutting-edge technology company specializing in open-source Vector Search designed for next-generation AI applications. Our platform enables high-performance vector similarity search, allowing businesses to unlock deep insights from unstructured data. By offering both open-source software and managed cloud solutions, we empower developers and enterprises to build scalable, AI-driven search and recommendation systems with ease. Our offering runs on major cloud providers in regions worldwide.

We are seeking a talented and product-minded Senior Backend Engineer with strong expertise in building resilient systems as well as having a good understanding in how to make them accessible.

While expertise in vector databases is not required for this role, we highly value experience in billing and payments, where handling complex transactions at scale is a critical challenge.

As a Senior Software Engineer (Payments), you will design, build, and maintain robust backend systems. The main focus of your work will be related to billing and payments, which is: precise usage metering, PSP integrations, sales and backoffice extension, reporting among others. You will work in a small multidisciplinary team and collaborate transversally with other cross-functional teams.

This role emphasizes Python as the primary backend language, though familiarity with Go is a plus. Experience with a reactive frontend framework (React, Vue, or similar) is very beneficial.

We prefer to hire someone working in timezone UTC +/- 4h

This is what you can expect when working with us.

• Design, develop, and maintain billing and payment systems with high precision and attention to detail.


• Extend integrations with payment gateways (e.g., Stripe, Adyen, PayPal, Braintree) and marketplaces (e.g., Amazon, eBay, Shopify, App Stores).


• Design and implement user-friendly interfaces and interaction flows for billing and payment systems, ensuring accessibility for non-technical users such as accounting staff, customer support, end users or growth teams


• Extend monitoring and alerting.


• Implement fraud detection mechanisms, chargeback handling.


• Collaborate closely with product managers, frontend engineers, and other backend engineers to create user-friendly and frictionless payment experiences.


• Ensure regulatory compliance (e.g., PCI-DSS, GDPR) in payment implementations.

This is what we expect from you to join us.

• Strong product mindset, with a deep understanding of how payments impact user experience and business success.


• Strong problem-solving and expression skills, to work in a remote environment.


• Proficiency in Python (FastAPI, Django, Flask, or similar).


• Strong understanding of relational databases, in particular PostgreSQL.


• Excellent sense for sustainable code


• Understanding of transaction lifecycles, refunds, chargebacks, and fraud detection.


• Experience with at least two of: event sourcing, billing systems, payment processing systems, payment gateways, and marketplace integrations.


• Participation in collaborative, test-driven development.


• Capability to visualise data


• Familiarity with Kubernetes, Docker, and cloud platforms (AWS, GCP, or Azure).


• Understanding of distributed systems and high-volume transaction processing.


• Ability to extend a reactive frontend stack is not frequently required, but should be possible.


• Experience with Go is a plus.

Nice-to-Have

• Exposure to machine learning for fraud detection.


• Experience in eCommerce, fintech, or large-scale SaaS platforms.


• Knowledge of real-time payments (RTP), open banking, or crypto payment solutions.


• gRPC experience is a plus.


• Familiarity with vector databases or search engines (not required but a plus).

• Competitive salary and benefits package.


• Fully remote work environment with flexible working hours.


• Opportunity to work on cutting-edge technology with a team of highly skilled engineers.


• Career growth and learning opportunities in a fast-growing industry.


• Collaborative and inclusive company culture.