This post is co-written with Liam Pearson, a Data Scientist at Genworth Mortgage Insurance Australia Limited.
Genworth Mortgage Insurance Australia Limited is a leading provider of lenders mortgage insurance (LMI) in Australia; their shares are traded on Australian Stock Exchange as ASX: GMA.
Genworth Mortgage Insurance Australia Limited is a lenders mortgage insurer with over 50 years of experience and volumes of data collected, including data on dependencies between mortgage repayment patterns and insurance claims. Genworth wanted to use this historical information to train Predictive Analytics for Loss Mitigation (PALM) machine learning (ML) models. With the ML models, Genworth could analyze recent repayment patterns for each of the insurance policies to prioritize them in descending order of likelihood (chance of a claim) and impact (amount insured). Genworth wanted to run batch inference on ML models in parallel and on schedule while keeping the amount of effort to build and operate the solution to the minimum. Therefore, Genworth and AWS chose Amazon SageMaker batch transform jobs and serverless building blocks to ingest and transform data, perform ML inference, and process and publish the results of the analysis.
Genworth’s Advanced Analytics team engaged in an AWS Data Lab program led by Data Lab engineers and solutions architects. In a pre-lab phase, they created a solution architecture to fit specific requirements Genworth had, especially around security controls, given the nature of the financial services industry. After the architecture was approved and all AWS building blocks identified, training needs were determined. AWS Solutions Architects conducted a series of hands-on workshops to provide the builders at Genworth with the skills required to build the new solution. In a 4-day intensive collaboration, called a build phase, the Genworth Advanced Analytics team used the architecture and learnings to build an ML pipeline that fits their functional requirements. The pipeline is fully automated and is serverless, meaning that there is no maintenance, scaling issues, or downtime. Post-lab activities were focused on productizing the pipeline and adopting it as a blueprint for other ML use cases.
In this post, we (the joint team of Genworth and AWS Architects) explain how we approached the design and implementation of the solution, the best practices we followed, the AWS services we used, and the key components of the solution architecture.
Solution overview
We followed the modern ML pipeline pattern to implement a PALM solution for Genworth. The pattern allows ingestion of data from various sources, followed by transformation, enrichment, and cleaning of the data, then ML prediction steps, finishing up with the results made available for consumption with or without data wrangling of the output.
In short, the solution implemented has three components:
- Data ingestion and preparation
- ML batch inference using three custom developed ML models
- Data post processing and publishing for consumption
The following is the architecture diagram of the implemented solution.
Let’s discuss the three components in more detail.
Component 1: Data ingestion and preparation
Genworth source data is published weekly into a staging table in their Oracle on-premises database. The ML pipeline starts with an AWS Glue job (Step 1, Data Ingestion, in the diagram) connecting to the Oracle database over an AWS Direct Connect connection secured with VPN to ingest raw data and store it in an encrypted Amazon Simple Storage Service (Amazon S3) bucket. Then a Python shell job runs using AWS Glue (Step 2, Data Preparation) to select, clean, and transform the features used later in the ML inference steps. The results are stored in another encrypted S3 bucket used for curated datasets that are ready for ML consumption.
Component 2: ML batch inference
Genworth’s Advanced Analytics team has already been using ML on premises. They wanted to reuse pretrained model artifacts to implement a fully automated ML inference pipeline on AWS. Furthermore, the team wanted to establish an architectural pattern for future ML experiments and implementations, allowing them to iterate and test ideas quickly in a controlled environment.
The three existing ML artifacts forming the PALM model were implemented as a hierarchical TensorFlow neural network model using Keras. The models seek to predict the probability of an insurance policy submitting a claim, the estimated probability of a claim being paid, and the magnitude of that possible claim.
Because each ML model is trained on different data, the input data needs to be standardized accordingly. Individual AWS Glue Python shell jobs perform this data standardization specific to each model. Three ML models are invoked in parallel using SageMaker batch transform jobs (Step 3, ML Batch Prediction) to perform the ML inference and store the prediction results in the model outputs S3 bucket. SageMaker batch transform manages the compute resources, installs the ML model, handles data transfer between Amazon S3 and the ML model, and easily scales out to perform inference on the entire dataset.
Component 3: Data postprocessing and publishing
Before the prediction results from the three ML models are ready for use, they require a series of postprocessing steps, which were performed using AWS Glue Python shell jobs. The results are aggregated and scored (Step 4, PALM Scoring), business rules applied (Step 5, Business Rules), the files generated (Step 6, User Files Generation), and data in the files validated (Step 7, Validation) before publishing the output of these steps back to a table in the on-premises Oracle database (Step 8, Delivering the Results). The solution uses Amazon Simple Notification Service (Amazon SNS) and Amazon CloudWatch Events to notify users via email when the new data becomes available or any issues occur (Step 10, Alerts & Notifications).
All of the steps in the ML pipeline are decoupled and orchestrated using AWS Step Functions, giving Genworth the ease of implementation, the ability to focus on the business logic instead of the scaffolding, and the flexibility they need for future experiments and other ML use cases. The following diagram shows the ML pipeline orchestration using a Step Functions state machine.
Business benefit and what’s next
By building a modern ML platform, Genworth was able to automate an end-to-end ML inference process, which ingests data from an Oracle database on premises, performs ML operations, and helps the business make data-driven decisions. Machine learning helps Genworth simplify high-value manual work performed by the Loss Mitigation team.
This Data Lab engagement has demonstrated the importance of making modern ML and analytics tools available to teams within an organization. It has been a remarkable experience witnessing how quickly an idea can be piloted and, if successful, productionized.
In this post, we showed you how easy it is to build a serverless ML pipeline at scale with AWS Data Analytics and ML services. As we discussed, you can use AWS Glue for a serverless, managed ETL processing job and SageMaker for all your ML needs. All the best on your build!
Genworth, Genworth Financial, and the Genworth logo are registered service marks of Genworth Financial, Inc. and used pursuant to license.
About the Authors
Liam Pearson is a Data Scientist at Genworth Mortgage Insurance Australia Limited who builds and deploys ML models for various teams within the business. In his spare time, Liam enjoys seeing live music, swimming and—like a true millennial—enjoying some smashed avocado.
Maria Sokolova is a Solutions Architect at Amazon Web Services. She helps enterprise customers modernize legacy systems and accelerates critical projects by providing technical expertise and transformations guidance where they’re needed most.
Vamshi Krishna Enabothala is a Data Lab Solutions Architect at AWS. Vamshi works with customers on their use cases, architects a solution to solve their business problems, and helps them build a scalable prototype. Outside of work, Vamshi is an RC enthusiast, building and playing with RC equipment (cars, boats, and drones), and also enjoys gardening.