Teng Yee Jing

Around end of 2020, Singapore government secured the COVID-19 vaccine stocks. However, a highly available, scalable and reliable system is required for the COVID-19 vaccination programme.

After rounds of brainstorming, the management decided to implement the systems with AWS Serverless services, mainly Amazon SQS and AWS Lambda. Most of the team did not have experience with AWS services, including me. However, I decided to take the challenge and recommended myself as AWS developer.

I picked up the knowledge quickly with guidance from two experienced teammates. During the development stage, I participated in many solution architecture discussions. Beyond the paper discussion, we also performed load tests and found all the possible bottlenecks.

Within two weeks, we successfully deployed a resilient system to production. We had a weekly release to enhance the system as the requirements often changed. To simplify the repetitive deployment, we used Terraform to manage AWS infrastructure as code and set up approval-control CI/CD with Azure Pipelines.

This system has benefited the entire Singapore population to overcome the pandemic. I am proud to contribute to this project and overcome the challenge.

AWS services used: Lambda, SQS, API Gateway, DynamoDB, CloudWatch...

When I just started working in IHiS, I joined the backend team of HealthHub. The backend services are mainly developed with Microsoft technology, including .NET Framework, ASP.NET and Microsoft SQL Server. Besides the backend services to serve the end-user, I have to build an intranet admin portal for the operation team to perform production support. I also develop tools to generate usage statistics from millions of audit logs.

SingHealth and NUHS planned to extend the features on their own mobile application (Health Buddy and OneNUHS), and these features had already existed in HealthHub. The backend team changed the direction to provide multi-tenancy backend services to support different channel apps.

As the demand raised, the team decided to perform technology refresh to a microservices solution with .NET Core. We aimed to deliver cloud-native containerized microservices to achieve high availability, scalability and reliability. I actively participated in technical design discussions and development.

I joined the team as a fresh graduate and improved rapidly. From my second year as junior engineer, I performed my tasks with minimal supervision and provided valuable feedback on solution design. I was requested many times to present my solution to team members.

Check out the website here

When the business owner contacted me initially, he only planned to update their website pricing page -- adding simple price calculations and replacing the plaintext price list with a table.

During the first discussion with the management team, I learned that they were dissatisfied with the existing website. Compared to the competitors' websites, their website looked less professional. It needed longer loading time and lost over search ranking due to bad SEO. However, they still paid hundreds of Malaysia Ringgit annually for server hosting and cPanel license. So I propose to remake the entire website, optimize the page for search ranking, and deploy with AWS Serverless services to minimize the cost.

I used Figma to create an interactive prototype for the owner to review the design. To outperform the competitors' websites, I suggested making the pricing table filterable and searchable so the user can easily find the price. And they decided to accept my proposal to remake the website.

The final product is fully serverless, and they only need to pay based on the website traffic. It also takes minimal effort to update the price list with my local tools. I set up analytic dashboards on Google Analytics, Google Search Console and Bing Webmaster Tools to understand website search ranking and utilization.

AWS services used: S3, CloudFront, Route 53, Certificate Manager, CloudFormation...