Full Stack Engineer (Kotlin / GCP), Payments Connectivity

About the Role

You will join a team that builds and runs payment connectivity services integrating a large-scale online payments platform with external payment service providers. You will own features end to end across backend services, serverless components, cloud infrastructure, and CI/CD, and contribute to the customer-facing payment flows.

What You’ll Do

• Design, build, and maintain backend services that integrate with payment service providers for payment initiation and status retrieval.
• Develop and support webhook and callback handlers that process asynchronous payment events reliably and securely.
• Implement secure data exchange, including payload encryption and decryption and managed secrets.
• Define and maintain well-documented APIs that follow internal standards and are validated through automated checks.
• Secure inbound and outbound traffic using API gateway, edge, and cloud security controls.
• Manage cloud infrastructure as code and deploy services on a serverless, container-based platform.
• Build and improve CI/CD pipelines covering testing, validation, release automation, and deployment.
• Support production through monitoring, incident triage, root-cause analysis, and payment status reconciliation.
• Contribute to platform and edge improvements and to technical documentation.
• Collaborate with platform teams and external provider contacts.

Required Skills

• Strong backend experience in Kotlin (or Java with a readiness to work in Kotlin) and a modern framework such as Micronaut or Spring Boot.
• Hands-on experience with Google Cloud Platform (serverless compute, messaging, load balancing, security, secret management).
• Experience designing and consuming REST APIs and OpenAPI specifications, and working with API gateways.
• Solid understanding of webhook and callback patterns, idempotency, retries, and failure handling.
• Working knowledge of encryption and secure data exchange.
• Infrastructure as Code with Terraform.
• CI/CD with GitHub Actions or an equivalent tool.
• Strong testing discipline (unit, integration, contract) and observability practices.

Nice to Have

• Experience in payments or fintech, including PSP integrations, reconciliation, and PCI-DSS awareness.
• Knowledge of CDN and edge security (WAF, routing, security rules).
• Frontend skills (TypeScript, React or similar) for payment, redirect, or status-handling flows and internal tooling.
• Familiarity with regional payment methods and regulatory guidelines.
• Experience with event-driven architectures and microservices.
• Experience with monitoring tools such as Dynatrace, Splunk, Prometheus, or Grafana.