Client Industry: Healthcare Technology & Medicare Services
Engagement Type: Data Platform Modernization, Streaming Integration, Application Development
Technologies: AWS (Lambda, ECS, Kinesis, S3, API Gateway, CloudFormation, Aurora), Apache Spark, Java (Spring Boot), C#, ASP.NET, MSSQL, DynamoDB, React, TypeScript, Angular, NestJS, Elasticsearch, HL7, FHIR
A Keyhole consultant supported a healthcare technology organization across multiple long-running initiatives focused on data platform modernization, real-time healthcare integrations, and mission-critical application development. The work spanned several systems and evolved alongside the client’s transition from on-premise infrastructure to AWS-based, cloud-native architectures.
Data Platform Modernization:
The engagement began with a large-scale transition from legacy on-premise databases to AWS. Data sets were exported to Amazon S3, transformed using Apache Spark on EC2, and streamed through AWS Kinesis into AWS Lambda for conversion into FHIR-compliant data structures. The consultant designed and implemented a generic CSV-driven mapping library that dynamically converted result sets into FHIR object graphs, enabling flexible, repeatable data transformations without code changes. Processed data was stored in Elasticsearch for downstream access and analytics.
Healthcare Application Development:
The consultant later contributed to a patient care application used by healthcare providers to ensure consistency of care year over year. The solution included a React and TypeScript single-page application hosted on AWS S3 and CloudFront, backed by Spring Boot services running in AWS ECS with DynamoDB persistence. As a vertical team member, the consultant worked across frontend, backend, and infrastructure concerns.
Enrollment & Insurance Systems:
The focus shifted to a Medicare enrollment application consisting of C# batch processing, an ASP.NET web application, and an MSSQL backend. The consultant supported all aspects of the system, including data processing, application logic, and ongoing enhancements critical to enrollment operations.
Real-Time HL7 Streaming Platform:
In parallel, the consultant led work on a real-time healthcare integration platform that processed incoming HL7 message streams using Java Spring Boot microservices on AWS. The system leveraged Kinesis, Lambda, API Gateway, Aurora, and S3 to build mastered patient encounter records, transform them into FHIR Encounter objects, and securely publish them to partner systems via OAuth2-protected REST APIs.
To support operational visibility, the consultant also built a monitoring dashboard using NestJS and Angular, deployed as microservices in AWS.
Across all initiatives, the engagement emphasized scalable cloud architecture, reliable streaming data pipelines, healthcare interoperability standards, and hands-on senior engineering ownership, enabling the client to modernize legacy systems while supporting critical healthcare operations.
