SUMMARY

• Sr. Cloud & DevOps professional with 8 years of IT Experience as Cloud/DevOps Engineer, Build/release Engineer and Linux Systems Administrator with concentration on Continuous Integration, Continuous Deployment, Configuration Management, and expertise in cloud AWS and Azure along with using various tools like Docker, Kubernetes, Ansible, Chef, Jenkins, Git, Maven.
• Worked on AWS Services EC2, IAM, Subnets, VPC, Cloud Formation, AMI, S3, SNS, SES, RedShift, CloudWatch, SQS, Route53, CloudTrail, Lambda, Kinesis and RDS and obtaining High Availability and Fault Tolerance for AWS EC2 instances utilizing the services like Elastic IP, EBS and ELB.
• Experience in AWS Cloud Formation templates to create customized VPC's, subnets and NAT to ensure successful deployment of Web applications, also expertise in AWS server less compute service Lambda and used AWS lambda to trigger changes in data shifts and action by users and run the code in the Postgres DB.
• Experience in Converting existing Terraform modules (IaaC) that had version conflicts to utilize CloudFormation templates during deployments, worked with Terraform to create stacks in AWS, and updated the Terraform scripts based on the requirement on regular basis.
• Experience in integrating Terraform with Ansible, Packer to create and Version the AWS Infrastructure, designing, automating, implementing and sustainment of Amazon machine images (AMI) across the AWS Cloud environment.
• Excellent knowledge in Azure compute services, Azure Web apps, Azure Data Factory & Storage, Azure Media & Content delivery, Azure Networking, Azure Hybrid Integration, and Azure Identity & Access Management.
• Experience in Azure IaaS, PaaS, Provisioning VM's, Virtual Hard disks, Virtual Networks, Deploying Web Apps and creating Web - Jobs, Azure Cosmos DB, Active Directory, Azure Windows server, Microsoft SQL Server, Microsoft Visual Studio, Windows PowerShell, Cloud infrastructure.
• Experience in cloud automation and orchestration framework using AWS and Azure. Implemented multi-tier application provisioning in cloud platforms, integrating it with PUPPET, migrating the application using MAVEN as build tool.
• Experience with setting up Chef Infrastructure, bootstrapping nodes, creating, and uploading recipes, node convergence in Chef SCM used Chef for server provisioning and infrastructure automation, release automation and deployment automation, Configure files, commands, and packages.
• Experience in designing and deploying container-based production clusters using Docker, Kubernetes, Docker Swarm, Docker compose, Dockerfile, EKS and AKS.
• Experience in Ansible setup, managing hosts file, using YAML, authoring various playbooks and custom modules with Ansible and worked on Ansible Playbooks to automate in AWS services like Launching EC2, Provisioning IAM, Configuring VPC, EBS, Monitoring using CloudWatch and CloudTrail.
• Migrated VMWARE VMs to AWS and Managed Services like EC2, SCS, S3, Route53, VPC, ELB, EBS, SNS, SES, Glue, RDS etc.., with Opscode Chef Cookbooks/Recipes.
• Hands on experience with puppet manifests for deployment and automation and have integrated Puppet with Jenkins to fully deploy on to a Jenkins server to provide with continuous deployment and testing to automate deployment of infrastructure.
• Experience in using Docker including Docker Hub, Docker Engine, Docker images, Docker compose, Docker swarm, and Docker Registry and used containerization to make our applications platform to be consistent flexible when they are moved into different environments.
• Experience in deploying Kubernetes Cluster on AWS and Azure cloud environments with master architecture and wrote many YAML files to create many services like pods, deployments, auto-scaling, load balancers, labels, health checks, Namespaces, Config Map etc.
• Experience in integrating Jenkins with various tools like Maven (Build tool), Git (Repository), SonarQube (code verification), Nexus (Artifactory) and implementing CI/CD automation for creating Jenkins pipelines programmatically architecting Jenkins Clusters.
• Experience in working on version control systems like GIT and used Source code management client tools like Git Bash, GitHub, Git GUI and other command line applications.
• Strongly proficient in Build and release of Cloud based products containing Linux and Windows environments, using Power Shell, TFS and Python Scripting and in object-oriented application using Java and scripting languages like Shell Scripting (Ksh, Bash), Ruby, PHP PERL scripts to totally automate AWS services.
• Experience in Branching, Merging, Tagging and maintaining the version across the environments using SCM tools like GIT and Bitbucket, Subversion (SVN) on Linux platforms.
• Experience in using build tools like MAVEN and ANT for the building of deployable artifacts such as war, jar and ear from source code. Involved in migrating the application from ANT to MAVEN by analyzing the dependencies and creating the POM's files to implement the build process using Maven.
• Exposure in writing Groovy and Ruby scripts for automation of build and infrastructure automation.
• Fluent in C, Python, Unix/Linux Scripting, Groovy, Ruby programming with excellent interpersonal, organizational and communication skills
• Experience in Nagios as a monitoring tool to identify and resolve infrastructure problems before they affect critical processes and worked on Nagios Event handlers in case of automatic restart of failed applications and services.
• Experience on ELK architecture and its implementation. Handled installation, administration and configuration of ELK stack on AWS and performed Log Analysis .
• Experience in deploying and configuring Elasticsearch, Log Stash, Kibana (ELK) and AWS Kinesis for log analytics and experienced in monitoring servers using Nagios, Splunk, CloudWatch .
• Experience in Group creation, monitoring and maintaining logs for system status/health using Linux commands and Splunk system monitor. Writing new plugins in Splunk to monitor.
• Worked on customizing Splunk dashboards, visualizations, configurations, reports and search capabilities using customized Splunk queries .
• Expert in writing scripts like Ruby, Perl, Power Shell, JSON, Node.js, YAML, Groovy, Bash/Shell, Python for automating the build and release process.
• Experience in Working with web servers such as Apache HTTP server, NGINX, Apache TOMCAT, application servers such as Oracle WebLogic 9.x/10.x, IBM WebSphere 6.x/7.x/8.x, JBoss 4.1.
• Knowledge of using Routed Protocols like FTP, SFTP, SSH, HTTP, HTTPS and Direct connect. And experience in Kickstart installations; support, configuration and maintenance of Red Hat Enterprise Linux, CentOS.
• Experience in system administration working on multiplatform VMware, LINUX (Red hat, SUSE), UNIX (Oracle Solaris 9/10) and windows server.
• Exposure to all aspects of Software Development Life Cycle (SDLC) such as Analysis, Planning, Development, Testing, Implementation, Post-production analysis of the projects.
• Excellent verbal and written communication and presentation skills.
• Problem solving and decision making skills Teamwork and Leadership and skills Team management skills

TECHNICAL SKILLS

Cloud Environment: AWS, Azure.

Configuration Management tools: Chef, Puppet, Ansible, Ansible Tower, Chef Automate

Build tools: Maven, Ant, Docker, MS Build, GRUNT.

Automation tools: Jenkins, Bamboo, Terraform, CloudFormation

Version Control tools: GIT, GIT-lab, TFS, Bitbucket, GitHub, Gutbucket, Subversion (SVN)

Operation systems: Sun-Solaris, Red Hat Linux, SUSE, Ubuntu, CentOS, Windows NT/2003/XP/2000, MacOS, UNIX

Web servers: Apache, Tomcat, JBOSS 4.x/5.x, Web Logic (8/9/10), Web Sphere4.0/5.0

Database System: MS SQL Server, MySQL, MongoDB, Oracle 9i/10g/12C, IBM DB2

Monitoring tools: Nagios, CloudWatch, Splunk, ELK-Xpack, GrayLog, Grafana, New Relics

Networking: DNS, DHCP, WAN, TCP/IP, NIS, NFS, SMTP, LAN, HTTP

Scripting: Python, Ruby, Bash shell, Power shell, JSON

Virtualization Technologies: VMware, Windows Hyper-V, Power VM, VirtualBox, Citrix Xen, Vagrant

Web Programming: HTML, CSS, XML, XSLT, jQuery

PROFESSIONAL EXPERIENCE

Sr. Cloud/ DevOps Engineer

Confidential, Lombard, IL

Responsibilities:

• Created AWS CloudFormation(IaC) Templates to create custom-sized VPC, subnets, EC2 instances, ELB, security groups. Managed other AWS Services like S3, Cloud Front, Cloud Watch, RDS, Kinesis, Redshift Cluster, Route53, SNS, SQS, Cloud Trail.
• Implemented AWS solutions using S3, RDS, EBS, Elastic Load Balancer, and Auto-scaling groups, Optimized volumes and EC2 instances and Using Jenkins AWS Code Deploy plugin to deploy to AWS.
• Worked with AWS CLI and AWS API to manage resources on AWS for many services such as EC2, S3, VPC, Cloud Watch, ELB, Auto-scaling, created python script using AWS API Calls to manage all resources deployed on AWS.
• Created custom machine images and automation tools like Chef/Ansible using Terraform along with packer to install software's after the infrastructure is provisioned.
• Involved in working with Terraform to bring up a count of container instances' or 'nodes' in an AWS ECS cluster with different instances running on each one.
• Experience with setting up Chef Infra, bootstrapping nodes, creating and uploading recipes, node convergence in Chef SCM.
• Created Chef Cookbooks and wrote recipes in Ruby Script to install and configured Infrastructure across environments and automated the process using Python Script.
• Installed and Implemented Ansible configuration management system. Used Ansible to manage Web applications, Environments configuration Files, Users, Mount points and Packages.
• Maintained high availability clustered and standalone server environments and refined automation components with scripting and configuration management (Ansible) and experienced in writing Ansible scripts.
• Experience with Container based deployments using Docker, working with Docker images, Docker Hub and Docker-registries and Kubernetes.
• Written groovy scripts to use multi branch pipeline projects in Jenkins to configure it as per client’s requirements.
• Developed procedures to unify streamline and automate applications development and deployment procedures with Linux container technology using Docker swarm and Docker compose.
• Worked on implementing microservices on Kubernetes Cluster and Configured Operators on Kubernetes applications and EKS and its components, such as Deployments, Config Maps, Secrets and Services. Pushed Docker images to ECR to deploy microservices on ECS.
• Configured Kubernetes Replication controllers to allow multiple pods such as Jenkins master server in multiple minions. Managed Kubernetes charts using Helm, managed Kubernetes manifest files and created reproducible builds of the Kubernetes application.
• Configured and administered Jenkins for automated builds and Responsible for installing Jenkins master and slave nodes and maintenance of build pipeline.
• Configuration of various plugins for Jenkins for automation of the workflow and to optimize and smooth running of build jobs.
• Managed Git repository, code merging, production deployments and analyzed and resolved conflicts related to merging of source code for Git.
• Developed tools using Python, Shell scripting, XML to automate some of the menial tasks. Interfacing with supervisors, artists, systems administrators and production to ensure production deadlines are met.
• Worked with MAVEN as a build tools on java projects for the development of build artifacts on the source code. Maintained build related scripts developed in shell for Maven builds, created and modified build configuration files including POM.xml.
• Responsible for log monitoring, auditing and enforcement of policies using New Relic Monitoring AWS Instances regularly using ops view and New Relic tools.
• Configuring and managing ELK stack, setup the elastic search ELK Stack to collect search and analyze log files from across the servers and integration of Application with monitoring tool New Relic for complete insight and proactive monitoring.
• Created Python scripts to totally automate AWS services which includes web servers, ELB, CloudFront distribution, database, EC2 and database security groups, S3 bucket and application configuration, this script creates stacks, single servers, or joins web servers to stacks.
• Experience in administering and maintaining Linux servers in production environments. Supported in the installation of packages/patches on Linux platforms. Implemented Backup & Disaster recovery management on Linux platforms.

Environment: AWS, Terraform, Chef, Ansible, Kubernetes, Docker, Jenkins, Maven, Git, Python/Shell/Perl/Ruby/PHP Scripts, Linux, ELK, New Relic, VMware, Tomcat Apache, JIRA, web &application servers, Networking.

Cloud/DevOps Engineer

Confidential, Raleigh, NC

Responsibilities:

• Created Azure Automation Assets, Graphical runbooks, PowerShell runbooks to automate specific tasks, deployed Azure AD Connect, configuring ADFS authentication flow, ADFS installation using Azure AD Connect.
• Deployed Azure IAAS, PAAS VM’s in Master Slave Architecture into ARM templates and Cloud services (PaaS role instances) into secure VNets with Azure’s Internal Load Balancer and subnets.
• Created and implemented ARM templates(IaC) and deployed them using the Azure portal, also used Azure quick start templates for Cloud Infrastructure design and implementation to Deploy Web applications on Azure PowerShell.
• Created and configured HTTP Triggers in the Azure Functions with Application insights for monitoring and performing load testing on the applications using the VSTS.
• Used Python API for uploading all the agent logs into Azure blob storage. Managed internal deployments of monitoring and alarm services for the Azure Infrastructure (OMS).
• Implemented Office 365 and Azure Active Directory for single sign-on, authentication, authorization, as well as Azure Role-based Access Control (RBAC).
• Established SSO connections using SAML 2.0 and OAuth 2.0 protocols in the AD and provided high availability for IaaS VMs and PaaS role instances for access from other services in the VNet with Azure Internal Load Balancer.
• Involved in migrating on-premises to Azure and built Azure Disaster Recovery Environment and Azure Backups from scratch using PowerShell Scripts.
• Created terraform templates(IaC) for provisioning virtual networks, subnets, VM Scale sets, Load balancers and NAT rules and used terraform graph to visualize execution plan using the graph command.
• Developed build and deploy scripts using Groovy , Python and UNIX for various products to be hosted on Application Servers
• Configured the Kubernetes provider with Terraform which is used to interact with resources supported by Kubernetes to create several services such as Config Map, Namespace, Volume, Auto scaler, etc.
• Managed Kubernetes charts using Helm. Created reproducible builds of the Kubernetes applications, templatize Kubernetes manifests, provide a set of configuration parameters to customize the deployment and Managed releases of Helm packages.
• Used Azure Kubernetes Service (AKS) and container instances to deploy scale, load balance, scale and manage Docker containers from the container registry with multiple namespace versions.
• Configured Automation with Centralized Management using Ansible and Cobbler . Implemented Ansible to manage existing servers to automate the build/configuration of new servers
• Wrote Ansible playbooks, inventories, created custom playbooks written in YAML language, encrypted the data using Ansible Vault and maintained role-based access control by using Ansible Tower.
• Implemented Chef recipes to automate Orchestration of Cassandra clusters and worked on upgrading Cassandra from old 2.x to 3.0 version.
• Used Chef recipes to set up the Continuous Delivery pipeline with Jenkins , SonarQube , Vagrant infrastructure to run these packages and various supporting software components such as Maven .
• Installed, deployed, and configured Chef Server Enterprise on-premise workstation. Bootstrapped the nodes using Knife and automated by testing Chef recipes and cookbooks with test-kitchen using different drivers Docker , Vagrant etc. with Chef-Zero and Chef-Solo in different platforms before sharing them in Chef-Server.
• Worked with Docker container snapshots, attaching to a running container, removing images, managing directories structures and managing containers.
• Included Vulnerability Detection as part of the CI/CD workflow using Jenkins Pipelines, SonarQube Quality Gates. Installed Jenkins/Plugins for GIT Repository, Setup SCM Polling for Immediate Build with Maven and Maven Repository (Nexus Arti factory).
• Built end to end CI/CD Pipelines in Jenkins to retrieve code, compile applications, perform tests and push build artifacts to Nexus and UDeploy to orchestrate changes across servers and components.
• Set up Jenkins server and build jobs to provide Continuous Automated builds based on polling the Git source control system during the day and periodically scheduled builds overnight to support development needs using Jenkins, Git, and Maven.
• Deployed new Splunk systems and monitor Splunk internal logs from the monitoring Console (MC) to identify and troubleshoot existing or potential issues.
• Replaced Splunk logging and analytics with an automated ELK cluster, increasing data capture capacity and reducing costs.
• Integrated applications together through scripts and other custom development. Experience working in deployment scripts in PowerShell, Python and Shell .
• Installed and configured ELK stack in legacy and pipelined application logs from App Server to Elastic search through Logstash.
• Writing ANT and Groovy scripts to automate the build process
• Defined and managed release and branching strategy of GIT servers. Also, helped educate engineering community on the appropriate use of GIT. As well as Implemented auto environment creation using Ansible and Azure.
• Worked with MAVEN for building the application, has written maven scripts and shell scripts to automate the build process. Daily maintenance of GIT source repositories and builds.
• Using Ruby, PowerShell, and Python scripting, Azure ARM (Itemplates developed automation and deployment.
• Created Azure PowerShell script for APIM backup and restore operations. Created several SQL scripts as part of bug fixes to provide immediate solutions for some of the common issues on Windows machines.
• Contributed towards the security model in the .NET framework for the administration module using Windows Authentication based on role-based security.
• Securing MongoDB using authentication and configuring, implementing and supporting High Availability with Load balancing (sharding) cluster of MongoDB having TB’s of data
• Setup Nginx, HTTP web server as a reverse proxy to critical applications such as Jira, Jenkins, and IBM WebSphere Application Server.
• Responsible for installing, updating, diagnosing and troubleshooting the issue tracking and project management application, learning agile methodology by JIRA.
• Supported infrastructure consisting of Windows 2008R2/2012R2/2016 servers . Configuration, administration of Windows OS on Standalone servers using Group Policy Objects, OS patch management (SCCM, WSUS) toolsets.

Environment: AWS, Terraform, Chef, Ansible, Kubernetes, Docker, Jenkins, Maven, Git, Python/Shell/Perl/Ruby/PHP Scripts, Linux, ELK, New Relic, VMware, Tomcat Apache, JIRA, web &application servers, Networking.

DevOps Engineer

Confidential

Responsibilities:

• Developed and supported the company's core AWS cloud infrastructure. Built and managed implementation of large Ubuntu Linux instances systems with Opscode.
• Provisioned infrastructure for environments building AWS CloudFormation stacks from the resources VPC, EC2, S3, RDS, Dynamo DB, IAM, EBS, Route53, SNS, SES, SQS, CloudWatch, Security Group, Auto Scale .
• Created NAT and Proxy instances in AWS and managed route tables, EIP's and NACLs . Configured Virtual Private Cloud (VPC) with networking of subnets containing servers.
• Created AWS CloudFormation templates to create custom-sized VPC’s , subnets, EC2 instances, ELB , security groups. Worked on tagging standard for proper identification and ownership of EC2 instances and other AWS Services like Cloud Front, RDS, Route53, SQS, Cloud Trail and worked on Simple Storage Service (S3), Simple Notification Service (SNS) and CloudWatch.
• Involved in Architect, build and maintain Highly Available secure multi-zone AWS cloud infrastructure utilizing Chef with AWS CloudFormation and Jenkins for continuous integration. Adding Compute nodes into OpenStack cloud platform. Responsible for supporting and maintaining Openstack in a production environment operational cloud platform services such as auto-remediation and service status API's.
• Set up Jenkins server and build jobs to provide Continuous Automated builds based on polling the Git source control system during the day and periodic scheduled builds overnight to support development needs using Jenkins, Git, and Maven.
• Integrated Docker container-based test infrastructure to Jenkins CI test flow and set up build environment integrating with Git and Jira to trigger builds using WebHooks and Slave Machines.
• Configured Jenkins as a common build engine maintained over 100 jobs in Jenkins from 10 different application teams for over 4-5 releases in parallel.
• Design and develop AWS cloud infrastructure utilizing Ansible with AWS CloudFormation and Jenkins for continuous integration with high availability and secure multi-zones and automated end-to-end transit hub connectivity resource deployment in AWS via Terraform.
• Wrote Chef Cookbooks for various DB configurations to modularize and optimize end product configuration, converting production support scripts to Chef Recipes and AWS server provisioning using Chef Recipes.
• Performed development and version control of Chef Cookbooks, testing of Cookbooks using Test Kitchen and running recipes on nodes managed by on-premise Chef Server.
• Wrote Shell Scripts for system applications, Application monitoring , Data feeds files transfers & log file analysis.
• Worked with CHEF ohai plugin, chef handlers, push jobs and exposure to chef supermarket to leverage the existing cookbooks for quick automation of general deployment and Infrastructure tasks.
• Integrated SonarQube with Jenkins using Maven to achieve Quality Analysis of all Projects pre-deployment. Discussed report with Developers to explain the effects of the Report and help improve code Quality.
• Installing and configuring Jenkins master and slave nodes. Built CI/CD pipeline and managing the infrastructure as code using chef.
• Implemented a Continuous Delivery pipeline with Docker, Jenkins and GitHub. Responsible for installation & configuration of Jenkins to support various Java builds and Jenkins plugins to automate continuous builds and publishing Docker Images to the Nexus Repository.
• Set up Kubernetes (k8s) Clusters for running microservices and Pushed microservices into production with Kubernetes backed Infrastructure. Development of automation of Kubernetes clusters via playbooks in Ansible.
• Used Kubernetes to deploy scale, load balance, scale and manage Docker containers with multiple namespace versions.
• Configured Kubernetes Replication controllers to allow multiple pods such as Jenkins master server in multiple minions. Managed Kubernetes charts using Helm , managed Kubernetes manifest files and created reproducible builds of the Kubernetes application.
• Used Shell and Perl scripting to deploy artifacts that are built by Maven and Ant. Installed and Configured Jenkins for Continuous Integration. Created Git repositories and structure. Managed branches and branching strategies in Git. Managed Dependencies using Maven.
• Worked on Docker engine and Docker Machine environments, to deploy the micro services-oriented environments for scalable applications, Docker swarm to host cluster and container scheduling, Docker compose to define multiple container applications.
• Virtualized servers using Docker as per test environments and Dev-environments requirements and configured automation using Docker containers.
• Written shell scripts with Bash, Python to automate tasks like provisioning servers, installing, configuring packages and deploying applications on multiple servers in the Prod & Non-prod environments.
• Worked on VMware application in Splunk in scheduling components that manage data collection tasks for API data. The Collection Configuration dashboard coordinates the flow of data with the data collection nodes.
• Automated Java Builds with Maven and Implemented multiple plugins for Code analysis, Junit, Code coverage, PMD, SonarQube , etc. Installed and administered Artifactory repos to deploy the artifacts generated by Maven.
• Wrote shell scripts using Bash, Python to automate tasks like provisioning servers, installing, configuring packages and deploying applications on multiple servers in the Prod & Non-prod environments.
• Worked on application/database team to resolve issues for performance Tuning and Management of Linux

Environment: AWS, GIT, GITHUB, SonarQube, Jenkins, Maven, Nexus, Ansible, Chef, LVM, Splunk, Nagios, DynamoDB, Python, shell scripting, Linux.

Build & Release Engineer

Confidential

Responsibilities:

• As member of the Release Engineering team, I redefined processes and implemented tools for software builds, patch creation, source control, and release tracking and reporting, on UNIX platform.
• Worked in Agile Project management Process, JIRA for Issue Tracking and monitoring and with the Architects on SDLC process taking ownership of post-development environments.
• Administered RedHat Linux 4.x/5 servers for several functions including managing Apace Tomcat Server, Mail Server, MySQL database and Firewalls in both development and production environments.
• Developed and maintained the build environment, the source code control system as well as managed build packages using GIT and GIT Hub.
• For check in process Tortoise SVN was used as a migration tool. Involved in migration of Bamboo server, Artifactory, Perforce & GIT server.
• Worked on Branching, Tagging and Release Activities on Version Control Tools (GIT) and Setting up the
• GIT repositories for Bamboo build jobs.
• Integrated Puppet with Apache and developed load testing and monitoring suites in Python.
• Scripting: Proficient in Hive, PIG, Shell Scripting, Perl Scripting, and Python.
• Configured Hadoop tools like Hive, Pig, Zookeeper, Hive.
• Developed various Bash shell scripts and Perl to automate resource, job monitoring and alerting for automation of the build and release process. Developed custom solutions in C# and validate availability, consistency, and compliance with different environments.
• Maintained several Modules in Puppet by converting production support scripts to Puppet Manifests to automate configurations in servers.
• Developed a custom puppet module skeleton to use same structure across all puppet modules.
• Developed Puppet scripts for an automated server provisioning and reduced time between provisioning and deployment from more than 3 hours to less than 10 minutes.
• Maintained build related scripts developed in shell for ANT builds. Created and modified build configuration files including Build.xml.
• Developed build and deployment scripts using ANT as build tool to move from one environment to an other.
• Resolved updates, merge and password authentication queries in Bamboo and JIRA.
• Worked closely with Web Administrators to understand, participate, and experience the technical architect for web sites such as Apache, JBoss, WebSphere, WebLogic and deploying J2EE Applications to these environments
• Involved in Ant and shell scripting for compilation and deployment process.
• Installed, upgraded, and configured Linux Servers using Kickstart as well as manual installations and the recovery of root password.

Environment: Linux, Perl, Puppet, Bamboo, Nagios, PHP, Ruby, JIRA, GIT, Vagrant, SVN, Ant, PowerShell, NT Command Shell.