Job description for Backend Engineer at PT Leap Digital Indonesia
ABOUT THE ROLE
We are seeking an experienced Backend Engineer to develop and maintain scalable backend services for an omnichannel clienteling platform. The role involves building microservices, integrating messaging systems and third-party platforms, and ensuring system performance, reliability, and security.
KEY RESPONSIBILITIES
- Develop and maintain backend services using Java and Spring Boot for conversation management, message routing, campaigns, and sales attribution.
- Design and optimize data models across PostgreSQL and MongoDB.
- Build event-driven architectures using Kafka, including message ordering, retries, and error handling.
- Develop and maintain integrations with the WhatsApp Business Platform, including message handling, webhooks, templates, and delivery status tracking.
- Implement phone number normalization and matching to connect incoming WhatsApp messages with customer records.
- Integrate chatbot, VoIP, and Microsoft Graph services, including bot-to-human handoff workflows.
- Implement real-time messaging using WebSockets and ensure horizontal scalability across multiple instances.
- Optimize backend services to support thousands of concurrent users while meeting performance and availability targets.
- Implement access control mechanisms using RBAC or ABAC, alongside customer data masking.
- Estimate tasks, manage development priorities, and deliver projects according to agreed timelines.
QUALIFICATIONS
- Minimum 4 years of backend development experience, including production experience with Java and Spring Boot.
- Strong proficiency in Java 21 or later and Spring Boot 4.
- Strong knowledge of PostgreSQL, including schema design, query optimization, indexing, and connection pooling.
- Production experience with Redis and Kafka.
- Experience with WebSockets or other long-lived connection systems at scale.
- Strong understanding of concurrency, idempotency, distributed locking, and consistency trade-offs in microservices.
- Experience with Spring Security, OAuth2, JWT, and implementing RBAC or ABAC.
- Experience with Docker, Kubernetes or ECS, CI/CD pipelines, and AWS or GCP.
- Experience writing unit and integration tests using JUnit and Testcontainers.
- Bachelor's degree in Computer Science, Information Technology, or a related field.
