Janus Chung

DevOps Engineer | Platform Engineer | SRE

Work Experience

Flagler Health

Software Engineer

Apr 2025 - Present

New York, NY

  • Bootstrapped Infrastructure as Code from scratch using Terraform, establishing S3 backend with DynamoDB state locking and importing existing AWS resources to improve visibility and IaC control.
  • Architected and implemented GitOps workflow using Argo CD, establishing Git as the single source of truth for all Kubernetes deployments across dev, staging, and production environments, transforming deployment strategy from bi-weekly releases to daily production deployments.
  • Redesigned CI/CD pipeline to implement "Build Once, Promote Forward" pattern, eliminating rebuild-per-environment and reducing build cost and time by ~70% by promoting the same validated artifact across all environments, transforming deployment time from hours to minutes.
  • Designed and deployed Argo Rollouts with custom analysis templates for automated canary and blue-green deployments, including metrics-based validation and automatic rollback on failure, reducing production incidents through progressive delivery.
  • Led zero-downtime upgrade of Argo CD from v2.12 to v3.0.2, including migration of Application definitions, AppProjects, and RBAC configurations, ensuring continued support and access to latest features.
  • Engineered migration of EKS node groups from x86 (m5.large) to ARM (Graviton2, m6g.large), including application compatibility testing, container image rebuilds for ARM64, and gradual workload migration with zero downtime, reducing infrastructure costs by ~40%.
  • Architected secrets management migration from dotenv.org to 1Password, implementing InitContainer-based secret injection using 1Password CLI (`op inject`), eliminating Git churn from encrypted blobs.
  • Integrated Argo CD with Slack webhooks for real-time deployment notifications, including success/failure status, commit SHA, and deployment duration metrics, improving team visibility and incident response time.
Terraform GitOps Argo CD Argo Rollouts Kubernetes EKS AWS CI/CD 1Password ARM

AD HOC LLC

Senior Software Engineer DevOps

Feb 2023 - Mar 2025

Washington, DC

  • Built and maintained CI/CD pipelines using Github Actions, Argo CD, DataDog and Hashicorp Vault.
  • Built and deployed Infrastructure as Code using Terraform to manage AWS resources.
  • Leveraged blue-green deployments with Argo Rollouts to improve release strategies and minimize downtime.
  • Created standardized platform EKS service to get Veterans Affairs API services onboard to AWS.
  • Created sample Java, Python and Ruby app and helm charts as reference for tenant to get onboard easier.
  • Built and managed Code VA, a catalog for discovering software within Department of Veterans Affairs.
  • Migrated cache and database components to Elasticache and RDS using Kubernetes CRD.
  • Migrated integration tests from Github Actions to Argo Rollouts's pre and post analysis template.
Terraform Argo CD Argo Rollouts EKS AWS Kubernetes CI/CD Github Actions DataDog Vault

Integral Ad Science (IAS)

Staff Software Engineer

Jun 2020 - Dec 2022

New York, NY

  • Built multiple microservices to migrate legacy monolith applications over to Kubernetes in AWS EKS which made feature updates faster and improved developer experience.
  • Designed and developed APIs for IAS pre-bid and post-bid platform using Spring Boot with a MySQL backend running in Tomcat. This project enabled IAS' clients to integrate with our targeting segments quickly.
  • Created a new microservice in AWS via ECS/Fargate. It was called Reporting API and it allowed clients to request reports programmatically.
  • Worked on integrating systems developed by the acquired company (Admantx). We had to receive their data and incorporate it as part of our pre-pid feature set.
  • Created multiple mock services with Spring Boot and Cucumber framework to improve development in non-production environment and enhance automated tests.
  • Mentored and helped new engineers integrate in IAS as part of the co-pilot program.
  • Created automated test-suites in Python for regression and acceptance tests.
  • Dockerized an existing monolith Spring application to improve developer experience. This project won in the company hackathon.
  • Conducted bi-weekly Lunch and Learn sessions for the team to present and discuss new technologies, and brainstorm improvement for our current tech stack.
Kubernetes EKS AWS Spring Boot MySQL ECS Fargate Docker Python Cucumber

Staff QAA Engineer

Jun 2015 - May 2020

  • Created headless XVFB and Chrome/Firefox test framework to speed up testing time by 80%.
  • Created a reusable testing environment for different products using Puppet that spins up AWS EC2 environments on demand.
  • Refactored legacy regression suite and cut testing time from 90 to 25 minutes.
Puppet AWS EC2 Selenium Test Automation

IV Interactive

Full Stack Software Engineer

Aug 2014 - Jun 2015

Jersey City, NJ

  • Designed and created a HIPAA compliant Web Application for IV Interactive using Laravel (PHP framework), MySQL, jQuery, Bootstrap, Skeleton, SASS/CSS3 and HTML5.
  • Created and maintained unit tests for the above using PHPUnit.
  • Proposed and implemented secure backups of codebase and database with PGP data encryption.
Laravel PHP MySQL jQuery Bootstrap PHPUnit

Media Three Corporation

Full Stack Software Engineer

Jun 2013 - Aug 2014

New York, NY

  • Implemented customer support system using CakePHP (PHP framework), MySQL, jQuery, CSS3. This was used to monitor customer complaints and inquiries.
CakePHP PHP MySQL jQuery

L & L Travel Enterprise, Inc

Senior Software Engineer DevOps

Aug 2012 - Jun 2013

New York, NY

  • Created and maintained the Online booking/tracking system for 500 travel agents using IIS, ASP, Javascript and SQL Server.
IIS ASP JavaScript SQL Server

Merck & Co., Inc

Informatica Developer (Consultant)

Jun 2011 - Feb 2012

Morristown, NJ

  • Worked on adding features and upgraded Informatica from version 4.2 to 5.3
Informatica ETL

DataSynapse, Inc

Senior Support Engineer

May 2007 - Nov 2009

New York, NY

  • Provided technical support for customers using DataSynapse software, a distributed computing application, on their mission-critical production systems in various platforms.
  • Developed sample code/examples of the DataSynapse API to make integrations for clients easier.
Distributed Computing API Technical Support

Applimation, Inc

Informia Support Consultant

May 2005 - Apr 2007

New York, NY

  • Provided technical support for customers using Applimation software.
  • Developed custom Oracle/PeopleSoft/Siebel SQL metadata for customers.
Oracle PeopleSoft Siebel SQL