Senior Java Developer - Part-Time

Key skills: Java, Kafka, MariaDB, Elasticsearch, MongoDB, Python 3.11+ / FastAPI framework)

What You'll Do

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

What We're Looking For

Required:

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)

Nice to Have:

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]

Familiarity with python language with version 3.11+

Has experience to use Java or Python libraries to process word, excel, pdf and ppt files

Thanks,

Saghana Sithara

BusinessManager, Recruitment| Quess Selection & Services, Singapore

EA LicenseNumber: 23C2060 Registration ID is R1550224

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“This is in partnership with the Employment andEmployability Institute Pte Ltd (“e2i”).

e2i is the empowering network for workers andemployers seeking employment and employability solutions. e2i serves as abridge between workers and employers, connecting with workers to offer jobsecurity through job-matching, career guidance and skills upgrading services,and partnering employers to address their manpower needs through recruitment,training, and job redesign solutions. e2i is a tripartite initiative of theNational Trades Union Congress set up to support nation-wide manpower andskills upgrading initiatives. By applying for this role, you consentto Quesscorp Singapore’s PDPA and e2i’s PDPA.”