# Derek T. > Senior Site Reliability Engineer at Persona Location: San Francisco, California, United States Profile: https://flows.cv/derekt Passionate technologist with 15+ years of experience in systems with a devops mindset. I am very adept at learning new technologies and choosing the best tool for the job through rigorous testing. Throughout my career, I have enabled developers through infrastructure, to deliver reliable, scalable, and repeatable software as a service with a focus on the customer experience. My expertise ranges from hardware to cloud providers and applications to automation. ## Work Experience ### Software Engineer @ Persona Jan 2022 – Present | San Francisco, California, United States ### Senior Site Reliability Engineer @ InfluxData Jan 2020 – Jan 2022 | San Francisco, California, United States - Manage 20 kubernetes clusters across 3 cloud providers. Using AKS, EKS, GKE, and kubeadm to manage the clusters. - Leverage ArgoCD to continuously deploy container images and kubernetes manifests to clusters. - Using terraform to manage AWS, Azure, GCP, New Relic, and Hahsicorp Vault. Configured Atlantis to plan/apply changes with github pull requests. - Contribute to our internal jsonnet manifests to deploy and manage applications on our kubernetes cluster. This includes converting helm charts to jsonnet objects to extend them for internal use. I have also refactored our jsonnet apps to use k8s libsonnet which adds classes and functions to jsonnet. - Managing Hashicorp Vault to provide a consistent secret storage platform, pki, and dynamic secrets across 3 cloud providers. I have also deployed the k8s-vault webhook to add vault agent side cars to provide secrets to k8s pods. - Serve as an architect in microservice application architecture discussions of Influx's cloud product. This includes major discussions to guide engineering teams towards microservice best practices such as; grpc protobufs, backend for front end model, and synchronous/asynchronous communications. - Setup Google Workspace as our SSO idp for Azure and AWS. - Manage istio deployment in our kubernetes clusters. ### Senior Infrastructure Engineer @ Credit Karma Jan 2019 – Jan 2020 | San Francisco Bay Area - Built a linux image pipeline using Packer, Saltstack, CircleCI, and Google Cloud Build. The image was designed to serve as a base image for all of Credit Karma and help transition configuration managed cloud images to an immutable deployment model. - Leveraged Terraform to manage Google Cloud instances, projects, IAM, and other requested resources. - Served as a linux application performance and application architecture consultant for Credit Karma. This sometimes involved being a resource during incidents to determine root cause and remediate incidents. ### System Engineer @ Square Jan 2014 – Jan 2019 | San Francisco Bay Area - Maintained Square’s production orchestration system, P2, written in Go. P2 enabled easy application deployment to three datacenters. P2 isolated applications using cgroups and linux kernel namespaces on CentOS servers. - Ensured smooth continuous deployment of 900+ microservices on P2 to support Square’s production application infrastructure. - Utilized Packer and SaltStack to build AWS AMIs. Leveraged SaltStack Grains to create roles which configured three image types for an AWS based Kubernetes deployment. - Leveraged Terraform to deploy images built with Packer as well as configure networks, security groups, EKS cluster, and a SSH bastion instance in AWS. - Managed a small cluster of Docker hosts which hosted 25 internal applications for Developers. - Deployed a centralized log aggregation system using Elasticsearch, Logstash, and Kibana (ELK). Processed 12GB per day for 250+ systems in 4 locations. - Maintained a Rails application to simplify ec2 instance creation and application deployment for developer sandboxes. The service managed 90+ active ec2 instances daily. - Maintained AWS management scripts using AWS Ruby SDK to provision S3 buckets and IAM access roles for developers. - Wrote a tool in Go to manage and escrow recovery keys for 30 Ubuntu luks full disk encrypted workstations. - Managed 300 Ubuntu and CentOS servers running on VMware using Foreman and Puppet. Foreman enabled us to standardize OS deployments by templating CentOS kickstart and Ubuntu preseed files. Foreman also provided us a reporting view for puppetdb data. - Wrote Puppet modules that enabled dynamic system customization with Hiera. This enabled us to write less manifests and use Hiera to configure servers. Hiera provided flexibility to customize based on OS type, location, system role, or specific host needs. Through Hiera GPG, we were able to deliver encrypted passwords, api keys, and certificates to hosts. ### DevOps Engineer @ Shotgun Software Jan 2011 – Jan 2014 | San Francisco Bay Area - Architected and transitioned several application components to Amazon Web Services including S3, Route 53 and EC2. - Wrote python script to migrate and manage Route 53 domains and zone data in AWS. - Built an automated RPM build environment using Jenkins. - Utilized Puppet to manage 25 CentOS servers hosting Shotgun’s production Rails applications. ### Network Server Administrator @ Autodesk Jan 2010 – Jan 2011 - Architected, prototyped, and built a private cloud. As a side project I worked with a few coworkers to design, prototype, and build an internal private cloud. - Managed migration from Sun Solaris to RHEL. - Consulted with enterprise Java application developers. ### Infrastructure Engineer/System Analyst @ Autodesk Jan 2007 – Jan 2010 - Built and migrated our primary customer datacenter. As a key member in a small team, I assisted in the migration of eight SaaS applications and fifty terabytes of data. The primary goal for the datacenter was to reduce our physical footprint, reduce power usage, reduce cost, and better allow for expansion in the future. - Designed and remotely built a datacenter in Hong Kong. By using a combination of Windows sysprep, VMware templates, RHEL kickstart scripts, and Active Directory I automated the deployment of a datacenter remotely. - Stabilized the production VMware infrastructure. - Architected and built a VMware Labmanager development environment. ### Systems Administrator @ Ellie Mae, Inc Jan 2006 – Jan 2007 - Helped develop and implement virtualization technologies [VMware ESX, VI3, VMotion] that reduced power consumption by half but still maintained the same computing horsepower. - Reduced the provisioning process for new customers in half using new scripting techniques reducing the overhead of adding new customers. ## Education ### Management Information Systems University of Michigan ## Contact & Social - LinkedIn: https://linkedin.com/in/derektamsen - Portfolio: http://www.devopsderek.com - GitHub: https://github.com/derektamsen --- Source: https://flows.cv/derekt JSON Resume: https://flows.cv/derekt/resume.json Last updated: 2026-04-11