Java Developer(Spring Boot, Spring WebFlux, WireMock, BPM, Workflow Automation, Kubernetes, DynamoDB, RAGAS)

EXASOFT CONSULTING PTE. LTD.; Singapore; On-site; SGD 180,000 - 240,000; Full time

Job summary

EXASOFT CONSULTING PTE. LTD. seeks an experienced backend engineer to lead scalable Java/Spring applications. You will design reactive services with WebFlux, build RESTful APIs, and drive microservices capable of complex business logic.

The role requires BPM experience, API testing with WireMock, and strong DB skills across PostgreSQL, MySQL, Oracle DB, and DynamoDB. AI features with pgvector and Langfuse are a plus.

Qualifications

• 8+ years in software development, backend architecture, and integration.
• Strong Java/Spring Boot experience with Spring WebFlux.
• Proficient in REST APIs, microservices, and distributed systems.
• BPM, workflow automation, and API testing with WireMock or similar.
• Relational and NoSQL DBs: PostgreSQL, MySQL, Oracle DB, DynamoDB.
• AI-enabled development with pgvector, RAG pipelines, Langfuse, and RAGAS.

Responsibilities

• Lead backend development and maintenance of scalable apps in Java/Spring.
• Design reactive services with Spring WebFlux for async processing.
• Develop and maintain RESTful APIs for internal and external use.
• Build microservices to meet complex business requirements.
• Implement BPM solutions and automate workflows for efficiency.
• Create API contract tests using WireMock; uphold unit/integration tests.
• Manage data with PostgreSQL, MySQL, Oracle DB, and DynamoDB.
• Contribute to AI-enabled apps using vector search (pgvector) and RAG.
• Use Langfuse and RAGAS to monitor AI performance; optimize where needed.
• Support AWS cloud deployment, Docker/Kubernetes, and CI/CD pipelines.
• Mentor, review code, and guide technical delivery across teams.

Skills

Java

Spring Boot

Spring WebFlux

Reactive programming

REST APIs

Microservices

BPM

API security

Python

FastAPI

React

Next.js

JavaScript

HTML

CSS

pgvector

Langfuse

RAG pipelines

RAGAS

AWS

Docker

Kubernetes

CI/CD

Tools

WireMock

PostgreSQL

MySQL

Oracle DB

DynamoDB

AWS

Docker

Kubernetes

CI/CD pipelines

RAGAS

Langfuse

pgvector

Job description

Responsibilities

• Lead the development and maintenance of scalable backend applications using Java and Spring Boot.
• Design and implement reactive services using Spring WebFlux to support efficient, asynchronous request processing.
• Develop and maintain RESTful APIs for seamless communication between applications and external systems.
• Design and enhance microservices-based solutions to support complex business requirements.
• Implement business process management solutions and automate workflows to improve operational efficiency.
• Develop API contract tests using WireMock and establish effective unit and integration testing practices.
• Manage application data using SQL and NoSQL databases, including PostgreSQL, MySQL, Oracle DB, and DynamoDB.
• Contribute to AI-enabled application development using vector search, pgvector, and retrieval-augmented generation (RAG) techniques.
• Apply tools such as Langfuse and RAGAS to monitor and evaluate AI application performance where applicable.
• Support cloud-based application deployment and maintenance using AWS, Docker, and Kubernetes.
• Maintain CI/CD pipelines and improve build, testing, and deployment processes.
• Collaborate with cross-functional teams, conduct code reviews, mentor developers, and guide technical implementation.
• Troubleshoot production issues, optimise application performance, and ensure code quality and system reliability.

Requirements

• Minimum 8+ years of experience in software development, backend architecture, and enterprise application integration.
• Strong experience in Java, Spring Boot, and backend application development.
• Hands-on experience with Spring WebFlux and reactive programming.
• Experience in RESTful APIs, microservices architecture, and distributed systems.
• Experience with BPM solutions and business workflow automation.
• Experience with WireMock or similar tools for API contract testing.
• Experience with relational databases such as PostgreSQL, MySQL, or Oracle DB, along with NoSQL databases such as DynamoDB.
• Experience in automated testing, including unit and integration testing.
• Experience in AWS cloud services, Docker, Kubernetes, and CI/CD pipelines.
• Experience in API security, authentication, and authorisation mechanisms.
• Experience in Python and backend frameworks such as FastAPI is an advantage.
• Experience with React, Next.js, JavaScript, HTML, and CSS for full-stack application development.
• Experience in pgvector, RAG pipelines, Langfuse, and RAGAS for AI-integrated applications.
• Strong analytical, problem-solving, communication, and technical leadership skills.
• Ability to guide development teams, review code, and coordinate technical delivery.