Software Engineer

Rapsys Technologies Pte Ltd.; Singapore; On-site; SGD 70,000 - 110,000; Full time

Job summary

Rapsys Technologies Pte Ltd. is seeking a Software Engineer (Full Stack) to design, develop, and maintain microservices-driven web applications for financial industry solutions.

You will work in an agile team on backend services using .NET Core/.NET 8 and Java, with Docker-based deployments and AWS cloud integration. You will collaborate with UX/UI designers, implement OAuth security, and ensure code quality with unit tests and AI-assisted reviews.

Qualifications

• Proven experience with .NET Core stack and microservices.
• Strong skills in .NET Core, .NET 8, C#, Java and related backend technologies.
• Experience building microservices and event-driven designs.
• Proficiency with Entity Framework and database management.
• Familiarity with Docker and containerization.
• Knowledge of DDD principles and backend design.
• Experience implementing OAuth and secure authentication.
• Understanding of security best practices in backend development.
• Hands-on with AWS services (S3, Lambda, API Gateway, RDS).
• Frontend basics: HTML, CSS, JavaScript; ASP.NET and WebForms.
• Experience with unit tests and design systems (Storybook).
• Knowledge of OpenTelemetry and observability.
• Experience migrating legacy .NET Framework apps; IIS/Windows Server deployments.
• Experience with Oracle databases and SQL performance tuning.
• Familiar with Quarkus for cloud-native microservices.

Responsibilities

• Design, develop, and maintain microservices architecture using .NET Core, .NET 8 and Java.
• Implement event-driven architecture for inter-service communication.
• Use EF for efficient database interactions and management.
• Containerize applications with Docker for scalability and deployment flexibility.
• Apply DDD principles for clean, modular code structure.
• Implement OAuth for secure authentication and authorization.
• Enforce security best practices to protect data and systems.
• Leverage AWS services (S3, Lambda, API Gateway, RDS) for backend development.
• Develop RESTful APIs to connect frontend and backend.
• Apply Spec Driven Development (SDD) using Claude AI tooling.
• Support and migrate legacy .NET Framework (4.x) apps; plan modernisation.
• Manage hosting and deployment on IIS/Windows Server with config transforms.

Skills

.NET Core

C#

Java

Microservices

DDD

OAuth

Security best practices

AWS

Frontend basics (HTML/CSS/JS)

Unit tests

Education

Bachelor's degree in Computer Science

Tools

Docker

OpenTelemetry

Oracle databases

IIS / Windows Server

WebForms

ASP.NET

Quarkus

Storybook

Claude AI / SDD tooling

Job description

We're Hiring: Software Engineer!

Job Summary

As a Software Engineer (Full Stack), you will be responsible for the end-to-end solutioning and development of software and web applications. You will be part of an agile team responsible for products used by the Financial Industry and MAS officers for Financial Supervision function.

Key Responsibilities

Backend Development

• Design, develop, and maintain microservices architecture using .NET Core, .NET 8 and Java.
• Implement event-driven architecture to enable seamless communication between microservices.
• Utilize Entity Framework (EF) for efficient database interactions and management.
• Containerize applications using Docker for scalability and deployment flexibility.
• Apply Domain-Driven Design (DDD) principles to ensure clean and modular code architecture.
• Implement OAuth for secure authentication and authorization.
• Develop and enforce security best practices to safeguard sensitive data and systems.
• Utilize AWS services such as S3, Lambda, API Gateway, RDS, etc., for backend development.
• Develop RESTful APIs endpoints to facilitate communication between the frontend and backend.
• Apply Spec Driven Development (SDD) concepts in development of code via Claude AI technologies.
• Support and maintain legacy .NET Framework (4.x) applications, including migration pathways to modern .NET where applicable.
• Manage application hosting and deployment on IIS and Windows Server environments, including environment-specific configuration management using config transformations.

Frontend Development

• Develop responsive and user-friendly web applications using ASP.NET, including WebForm applications.
• Generate and review unit tests using generative AI to ensure code quality and reliability.
• Create reusable UI components and maintain a consistent design using Storybook.
• Collaborate closely with UX/UI designers to implement intuitive and visually appealing interfaces.
• Troubleshoot and debug issues across the stack, ensuring smooth application operation.
• Optimize application performance and scalability for a seamless user experience.

What we are looking for

Requirements

• Proven professional experience working on .NET Core stack.
• Strong proficiency in .NET Core, .NET 8, C#, Java and related backend technologies.
• Experience building microservices architecture and implementing event-driven design patterns.
• Proficiency in Entity Framework (EF) for database management.
• Familiarity with Docker and containerization principles.
• Knowledge of Domain-Driven Design (DDD) principles and their application in backend development.
• Experience implementing OAuth for authentication and authorization.
• Understanding of security best practices and their application in backend development.
• Hands-on experience with AWS services such as S3, Lambda, API Gateway, RDS, etc.
• Proficiency in frontend technologies such as HTML, CSS, and JavaScript, ASP.NET and WebForms.
• Experience writing unit tests and maintaining a design system with Storybook.
• Strong problem-solving skills and attention to detail.
• Excellent communication and collaboration skills.
• Knowledge and experience in utilizing generative AI to develop and review codes via Spec Driven Development (SDD).
• Hands-on experience with legacy .NET Framework (4.x) applications, including maintenance and incremental modernisation.
• Experience with Oracle databases, including query optimisation and integration with .NET applications.
• Proficiency in deploying and configuring applications on IIS and Windows Server, with working knowledge of Web.config transformations for environment-specific deployments.
• Hands-on experience with Java Quarkus framework, including building and deploying cloud-native microservices, with working knowledge of OpenTelemetry for distributed tracing and observability.

Preferred Qualifications

• Preferably more than 5 years of experience as a full stack software engineer.
• Experience working in both Unix and Windows operating environments are preferred.
• AWS certification (e.g., AWS Certified Developer, AWS Certified Solutions Architect).
• Experience with Node.js for server-side development.
• Familiarity with RDS databases such as MSSQL.
• Knowledge of CI/CD pipelines and DevOps practices.
• Understanding of Agile development methodologies.
• Experience with event-driven development patterns and architectures, as well as frontend development using React or other Single Page Application (SPA) frameworks.