
Madan Karuppiah engineered cloud infrastructure and deployment automation across several govuk-one-login repositories, focusing on production reliability and operational efficiency. He implemented canary deployments, CloudWatch monitoring, and API Gateway routing to live Lambda aliases, ensuring safer rollouts and robust incident detection. Using AWS CloudFormation, Lambda, and Docker, Madan built automated traffic testing pipelines and enhanced CI/CD workflows, reducing deployment risk and improving feedback cycles. His work included centralizing firewall management via FMS, refining alerting policies to reduce on-call noise, and maintaining infrastructure hygiene through template linting and configuration updates. These contributions demonstrated depth in DevOps, infrastructure as code, and cloud security.

July 2025 monthly summary for govuk-one-login/ipv-cri-common-lambdas: Focused on improving incident detection and deployment stability through CloudWatch alarm tuning in canary 5xx monitors. Delivered a feature to reduce evaluation periods and adjust rollback thresholds, with commits IPS-1894 showing. Impact: faster detection, reduced unnecessary rollbacks, and more reliable deployments. No major bugs fixed in this repository this month. Technologies demonstrated: CloudWatch monitoring, alerting, incident response workflows, and deployment hygiene.
July 2025 monthly summary for govuk-one-login/ipv-cri-common-lambdas: Focused on improving incident detection and deployment stability through CloudWatch alarm tuning in canary 5xx monitors. Delivered a feature to reduce evaluation periods and adjust rollback thresholds, with commits IPS-1894 showing. Impact: faster detection, reduced unnecessary rollbacks, and more reliable deployments. No major bugs fixed in this repository this month. Technologies demonstrated: CloudWatch monitoring, alerting, incident response workflows, and deployment hygiene.
June 2025 monthly summary focusing on business value and technical achievements across four ipv-cri repos. Delivered production-ready routing by updating API specs to use live Lambda aliases (ensuring public/private API Gateways consistently reach the current code) across ipv-cri-check-hmrc-api, ipv-cri-address-api, and ipv-cri-kbv-api. Implemented canary deployments and generic API Gateway mappings for ipv-cri-common-lambdas, enabling gradual rollouts and reliable service monitoring for Lime and CRI. Strengthened observability with CloudWatch alarms for Lambda errors and 5XX responses, with alarm stack integration improvements. Improved infrastructure quality through CFN linting fixes and template maintenance, removing unused parameters and tightening lint rules. Added necessary IAM permissions and mapping adjustments to prevent circular dependencies, supporting smoother, safer deployments.
June 2025 monthly summary focusing on business value and technical achievements across four ipv-cri repos. Delivered production-ready routing by updating API specs to use live Lambda aliases (ensuring public/private API Gateways consistently reach the current code) across ipv-cri-check-hmrc-api, ipv-cri-address-api, and ipv-cri-kbv-api. Implemented canary deployments and generic API Gateway mappings for ipv-cri-common-lambdas, enabling gradual rollouts and reliable service monitoring for Lime and CRI. Strengthened observability with CloudWatch alarms for Lambda errors and 5XX responses, with alarm stack integration improvements. Improved infrastructure quality through CFN linting fixes and template maintenance, removing unused parameters and tightening lint rules. Added necessary IAM permissions and mapping adjustments to prevent circular dependencies, supporting smoother, safer deployments.
During April 2025 for govuk-one-login/ipv-cri-bav-front, completed WAF migration from BAV CRI to Firewall Management Service (FMS), updated LoadBalancerListenerTargetGroupECS tagging, and aligned secret references in .secrets.baseline. These changes centralize firewall management, reduce configuration drift, and improve security governance, with a single traceable commit enabling auditability and rollback.
During April 2025 for govuk-one-login/ipv-cri-bav-front, completed WAF migration from BAV CRI to Firewall Management Service (FMS), updated LoadBalancerListenerTargetGroupECS tagging, and aligned secret references in .secrets.baseline. These changes centralize firewall management, reduce configuration drift, and improve security governance, with a single traceable commit enabling auditability and rollback.
February 2025 monthly summary for ipv-core-front focusing on API deployment configuration enhancements to support FMS migrations. Delivered changes that improve deployment reliability, migration readiness, and governance compliance while maintaining clear traceability.
February 2025 monthly summary for ipv-core-front focusing on API deployment configuration enhancements to support FMS migrations. Delivered changes that improve deployment reliability, migration readiness, and governance compliance while maintaining clear traceability.
December 2024 performance summary for govuk-one-login/ipv-cri-dl-api: Delivered a traffic test image pipeline with enhanced test workflow, implemented robust canary deployments for Lambda with monitoring, and fixed critical CI/CD reliability issues. These changes improved testing fidelity, reduced deployment risks, and enabled safer, phased releases with better observability.
December 2024 performance summary for govuk-one-login/ipv-cri-dl-api: Delivered a traffic test image pipeline with enhanced test workflow, implemented robust canary deployments for Lambda with monitoring, and fixed critical CI/CD reliability issues. These changes improved testing fidelity, reduced deployment risks, and enabled safer, phased releases with better observability.
Monthly work summary for 2024-11 focusing on govuk-one-login/ipv-cri-bav-api. Key features delivered include robust Lambda deployment and monitoring enhancements with canary deployments for PartialNameMatchFunction and CloudWatch alarms, plus automated traffic testing infrastructure with parallel execution. No separate major bug fixes recorded this month; the work emphasized reliability, observability, and faster feedback through testing automation. Overall impact includes safer deployments, reduced risk, and accelerated release validation. Technologies demonstrated include AWS Lambda, CloudWatch, API Gateway permissions, Node.js in Docker, AWS CLI, Docker, GitHub Actions, ECR, and CI/CD pipelines.
Monthly work summary for 2024-11 focusing on govuk-one-login/ipv-cri-bav-api. Key features delivered include robust Lambda deployment and monitoring enhancements with canary deployments for PartialNameMatchFunction and CloudWatch alarms, plus automated traffic testing infrastructure with parallel execution. No separate major bug fixes recorded this month; the work emphasized reliability, observability, and faster feedback through testing automation. Overall impact includes safer deployments, reduced risk, and accelerated release validation. Technologies demonstrated include AWS Lambda, CloudWatch, API Gateway permissions, Node.js in Docker, AWS CLI, Docker, GitHub Actions, ECR, and CI/CD pipelines.
October 2024 monthly summary for govuk-one-login/ipv-cri-bav-front focused on reducing alert noise in development and stabilizing non-prod environments. Delivered a targeted alerting fix to prevent PagerDuty from triggering for CloudWatch alarms and metric filters in development by switching the triggering condition from DeployAlarms to IsNotDevelopment. This change ensures ECS/API Gateway fatal error metrics and frontend error/latency alarms do not generate on-call paging in non-prod environments, aligning dev/test behavior with production expectations. Key commit: a9ae6f610977e1ff7c967f997ba8130fa84bbba9 (IPS-1181). Impact: lower on-call noise in development, faster triage in prod readiness, and safer deployment cycles.
October 2024 monthly summary for govuk-one-login/ipv-cri-bav-front focused on reducing alert noise in development and stabilizing non-prod environments. Delivered a targeted alerting fix to prevent PagerDuty from triggering for CloudWatch alarms and metric filters in development by switching the triggering condition from DeployAlarms to IsNotDevelopment. This change ensures ECS/API Gateway fatal error metrics and frontend error/latency alarms do not generate on-call paging in non-prod environments, aligning dev/test behavior with production expectations. Key commit: a9ae6f610977e1ff7c967f997ba8130fa84bbba9 (IPS-1181). Impact: lower on-call noise in development, faster triage in prod readiness, and safer deployment cycles.
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