At Klorie, we're building a next-generation payment platform tailored for European businesses. We're looking for a Senior Back-End Engineer to join our core engineering team. You’ll play a critical role in designing and maintaining the systems that power secure and scalable payment processing across multiple integrations.
As a Senior Engineer, you’ll architect and build robust APIs, maintain infrastructure, and help shape engineering practices that support compliance, resilience, and performance.
Core Responsibilities
- Design, implement, and maintain back-end services using Node.js, AWS Lambda, and Docker.
- Manage scalable infrastructure on AWS, focusing on cost efficiency and uptime.
- Build and optimize relational data models using SQL.
- Collaborate closely with front-end engineers, product managers, and compliance teams to ship reliable features.
- Implement secure, auditable, and compliant backend flows for payment operations.
- Create internal tools and APIs to support operations and integrations.
- Own your work end-to-end, from architecture to production monitoring.
- Review code, mentor peers, and contribute to system design decisions.
Requirements
- 5+ years of professional experience in backend engineering, ideally with Node.js.
- Deep understanding of AWS services, especially Lambda, S3, API Gateway, and CloudWatch.
- Strong SQL skills and experience working with transactional data.
- Proficient with Docker and containerized development.
- Experience designing and maintaining RESTful APIs.
- Familiar with CI/CD pipelines and infrastructure as code (Terraform or AWS CDK is a plus).
- Comfortable working in a startup-like, remote-first environment.
- Strong communication and collaboration skills.
Nice-to-Haves
- Experience in payment systems, fintech, or handling sensitive financial data.
- Familiarity with event-driven architectures and message queues (e.g., SNS/SQS, Kafka, etc.).
- Knowledge of TypeScript.
- Understanding of security and compliance standards (e.g., PCI-DSS).
- Monitoring and observability experience (Grafana, Prometheus, or similar).
- Familiarity with Clean Architecture or DDD principles.
Why Join Klorie?
- Impact: Join early and shape the future of a modern PSP.
- Growth: High ownership, high responsibility environment.
- Flexibility: Hybrid work model (1–2 days/week on-site in Belgium).
- Purpose: Help build fair, transparent, and reliable payment infrastructure.