Java Back End Engineer - Spring Boot / Quarkus (Min. 2 years Experience)

PT Loren Tech Solutions; Indonesia; On-site; IDR 72,540,000 - 78,120,000; Part time

Job summary

PT Loren Tech Solutions in Indonesia is seeking a Backend Engineer for a 12-month contract to join our on-site team. The role focuses on building scalable services using Java (17+) or Kotlin, with Spring Boot or Quarkus, and reactive programming.

You will work with REST, gRPC, GraphQL, and modern JVM tools, Docker and Kubernetes, to deliver production-grade backend systems. Prior experience in distributed systems and performance tuning is a plus.

Qualifications

• Min. 2 years of experience as a Backend Engineer.
• Strong proficiency in Java (17+) or Kotlin.
• Experience with Spring Boot or Quarkus in production environments.
• Good understanding of reactive programming (Project Reactor, RxJava, or Mutiny).
• Strong knowledge of database design, indexing, and query optimization.
• Familiar with Docker and Kubernetes.

Skills

Java (17+)

Kotlin

Go

Reactive programming

Spring Boot

Quarkus

Project Reactor

Mutiny

Spring WebFlux

REST

gRPC

GraphQL

Database design

Indexing

Query optimization

Docker

Kubernetes

Tools

Docker

Kubernetes

Job description

Employment Type: Contract (12 Months, extendable based on performance)

Work Arrangement: Full Onsite

Salary: Rp.6.500.000 Gross - 7.000.000 Gross (Base on experience)

• Framework: Spring Boot, Quarkus
• Languages: Java (17+) / Kotlin, Go (for selected services)
• Reactive: Project Reactor, Mutiny (Quarkus), Spring WebFlux
• API: REST, gRPC, GraphQL

Requirement

Must Have

• Min. 2 years of experience as a Backend Engineer.
• Strong proficiency in Java (17+) or Kotlin.
• Experience with Spring Boot or Quarkus in production environments.
• Good understanding of reactive programming (Project Reactor, RxJava, or Mutiny).
• Strong knowledge of database design, indexing, and query optimization.
• Familiar with Docker and Kubernetes.

Nice to Have

• Experience with event-driven architecture (Kafka or RabbitMQ).
• Familiar with Quarkus native build (GraalVM).
• Experience with distributed systems (Saga Pattern, CQRS, etc.).
• JVM performance tuning experience (GC tuning, profiling).
• Contributions to Java or Go open-source projects.