Accelerating development using AWS AML with Employment Hero

Employment Hero provides human resources, payroll, and recruitment solutions to over 300,000 businesses across several countries, including Australia, New Zealand, and the United Kingdom.

Australia has one of the most complex payroll systems in the world, with an award system that is based on government-determined conditions in addition to standard wages. So, there’s high demand for an application that simplifies this process. But Employment Hero’s payroll application was built on a monolithic application base and architecture whose complexity made it difficult to manage frequent changes and updates. “To change any part of the code, we needed to deploy a large monolithic code base,” says Alan Hynes, general manager of engineering at Employment Hero.

On that application base and architecture, the company had only one background queue processor for all workloads, so a resource-intensive task or an issue anywhere in the system could cause unacceptable delays elsewhere. “We’re one of the largest payroll providers in Australia,” says Hynes. “If we had an event, it would impact a lot of Australian citizens. We needed a highly resilient system.”

To improve resiliency and accommodate growth, Employment Hero needed to modernize its application base and architecture. So, the company decided to migrate from .NET Framework as its programming environment to cross-platform .NET. This way, it could increase scalability, optimize costs, and set its application up for long-term success.

Employment Hero had extensive discussions with the AWS team about business priorities and effective approaches. During these discussions, the company learned of AWS Application Modernization Lab (AWS AML)—a multiweek, three-phase AWS program focused on upskilling and accelerating customer cloud modernization strategies. So, Employment Hero decided to join the program, which is only available to top AWS customers, and developed a plan to modernize the payroll application. For example, by applying code-scanning tools to millions of lines of code, the teams uncovered ways to separate key workloads into six modules.

“AWS AML provided access to tools that we might not have had the required resources or expertise to run,” says Hynes. “The AWS team made the effort to understand our business and identify opportunities for us to use the breadth of AWS skills and knowledge.”

The teams evaluated different areas of code to determine the largest and most critical component. As a result, they decided to focus their modernization effort on the Pay Run module, which contained the application’s calculation engine. Over the next several months, the Employment Hero team worked to modernize the module into a container-based architecture. The company was already using containers on AWS in other areas and had seen the scalability and resiliency benefits of containerizing workloads. “It was always our dream to get payroll into a containerized environment, but we didn’t have a strategy to do that until joining the AWS AML program,” says Hynes.

Using cross-platform .NET, Employment Hero could select a solution for its containers to optimize resource usage. So, the team began migrating workloads to cross-platform .NET on Linux containers that ran on Amazon Elastic Container Service (Amazon ECS), a fully managed container orchestration service. “Our payroll team didn’t have a lot of experience in containerization, so we wanted to have more of a managed service,” says Hynes. To power the containerized workloads, Employment Hero also implemented AWS Fargate, a serverless, pay-as-you-go compute engine.

Shortly after starting the AWS AML program, the teams deployed the modernized Pay Run module to production. The migration reduced infrastructure, operational, and licensing costs, helping the company achieve 41 percent cost optimization. “The focus of the program was confined to Pay Run, but the blueprint that was formed there is applicable across the entire application stack,” says Hynes.

Using AWS services in a cross-platform .NET environment, Employment Hero has increased its release velocity by five times and expects to double its daily code deployments. The company improved agility through accelerating deployment by 83 percent and build time by 85 percent. Each developer saves about 4 hours per week—time that developers previously spent waiting for code deployments and compilations. This productivity increase equates to 340 hours saved per week.

By building on a containerized environment, the company enhanced the resiliency of its payroll application. Different tasks can run simultaneously without impacting performance. And with independent scaling for each component and improved fault isolation, Employment Hero can better protect the application against outages.

By migrating to cross-platform .NET and modernizing on AWS, Employment Hero built a foundation that supports further innovation. The company also plans to migrate all its workloads to AWS Graviton processors, which are custom-designed server processors developed by AWS to provide excellent price performance for cloud workloads running on Amazon Elastic Compute Cloud (Amazon EC2).

“The AWS AML program gave us direction and accelerated our modernization,” says Hynes. “It’s been foundational work that has prepared us to dream about bigger innovations in the future.”