Java Developer - Kafka

United States Digital Space LLC; Singapore; On-site; SGD 86,634 - 90,966; Part time

Job summary

United States Digital Space LLC seeks an experienced backend engineer to design, build, and maintain scalable services in Java. You will implement event-driven integrations with Kafka, design data models for MariaDB, and enable powerful search with Elasticsearch. Collaboration with cross‑functional teams and participation in code reviews are essential.

The role emphasizes REST API development, Docker/Kubernetes, and CI/CD workflows, with a contract engagement and in-person work location.

Qualifications

• 4+ years of professional backend Java development experience.
• Hands-on Kafka or similar message brokers in production.
• Strong SQL skills with MariaDB/MySQL.
• Experience with Elasticsearch including index design and queries.
• Solid OOP, multithreading, and REST API development.
• Familiarity with Spring/Spring Boot.
• Git and CI/CD workflows.
• Experience with Docker and Kubernetes.

Responsibilities

• Design, build, and maintain backend services and APIs using Java 11+ and Spring Boot.
• Develop event-driven integrations with Kafka (producers, consumers, streams).
• Model data and optimize queries in MariaDB/MySQL.
• Implement search and analytics with Elasticsearch and query optimization.
• Collaborate with product, DevOps, and QA to deliver scalable features.
• Write clean, tested code and participate in reviews.
• Diagnose performance bottlenecks across app and data layers.
• Contribute to architecture decisions around messaging and storage.
• Support CI/CD pipelines and incident response as needed.

Skills

Java backend development

Kafka messaging

SQL & MariaDB

Elasticsearch

REST API design

Spring Boot

CI/CD

Docker & Kubernetes

Tools

Docker

Kubernetes

Git

Schema Registry

Job description

Responsibilities

• Design, build, and maintain backend services and APIs using Java (Java 11+ / Spring Boot or equivalent)
• Develop and operate event-driven integrations using Apache Kafka (producers, consumers, streams, schema management)
• Design efficient data models and write performant queries against MariaDB (or other relational databases)
• Implement search and analytics features using Elasticsearch, including index design and query optimization
• Collaborate with cross‑functional teams (product, DevOps, QA) to deliver reliable, scalable features
• Write clean, well‑tested, maintainable code and participate in code reviews
• Diagnose and resolve performance bottlenecks across the application and data layers
• Contribute to architectural decisions around messaging, data storage, and service design
• Support CI/CD pipelines and participate in on‑call/incident response as needed

Qualifications

• 4+ years of professional experience developing backend applications in Java
• Hands‑on experience with Apache Kafka or similar message brokers (RabbitMQ, ActiveMQ) in production environments
• Strong SQL skills and practical experience with MariaDB or MySQL (schema design, indexing, query tuning)
• Experience with Elasticsearch, including index mapping design and search query construction
• Solid understanding of object‑oriented design, multithreading, and REST API development
• Familiarity with Spring / Spring Boot ecosystem
• Experience with version control (Git) and CI/CD workflows
• Strong debugging and problem‑solving skills in distributed systems
• Hands‑on experience with containerization (Docker, Kubernetes)

Preferred Skills

• Familiarity with schema registries (e.g., Confluent Schema Registry) and Avro/Protobuf
• Experience with observability tooling (Prometheus, Grafana, ELK stack)
• Knowledge of caching layers (Redis, Memcached)
• Experience using AI‑assisted development tools (e.g., Claude Code, GitHub Copilot) to accelerate coding, debugging, and refactoring workflows
• Comfort integrating AI coding agents into CI/CD or developer tooling pipelines
• Prior experience in [your industry, e.g., fintech, e-commerce]

Job Type: Contract

Pay: $6,000.00 - $6,300.00 per month

Work Location: In person