Mark L Callan



Objective

Seeking a position as a Senior/Principal Software Engineer where I can contribute my expertise in cloud scale automation, monitoring and management, and in-depth funtional knowledge of computer hardware and operating systems to a team of enthusiastic and passionate engineers.



Skills

Primary Languages:
  • Java
  • Python
  • C#
  • JavaScript
  • bash
Operating Environments:
  • Linux - Debian, EL, NixOS
  • Windows
Virtualization:
  • KVM/QEMU
  • Vagrant
  • VirtualBox
  • HyperV
Web:
  • HTML/CSS/LESS/JS
  • Dropwizard
  • .NET MVC
  • .NET WebAPI
  • WCF
  • Node.js
  • JQuery
  • Bower
  • Knockout
Dev Ops:
  • Docker
  • Ansible
  • Maven
  • Gradle
  • Jenkins
  • Team City
  • Oracle Deployment Orchestrator (Internal)
Hosting:
  • Oracle Cloud
  • GoogleCloud
  • Azure
  • AWS
  • IIS
  • Apache
  • NGINX
  • Kubernetes
Database:
  • MongoDB
  • MS SQL Server
  • MySQL
  • Oracle
Some Experience With:
  • AngularJS
  • Ruby
  • Scala
  • Rust
  • Go
  • C++
  • Kotlin
  • Groovy


Experience

July 2017 - Present
Oracle Cloud Infrastructure - Seattle, Washington
Senior Software Development Engineer

As a member of the VMI Dataplane team, managed a fleet of almost 30k hypervisors. This includes designing building and maintaining services that monitor and control the hypervisors, last line of 24/7 support for the customer service teams working with customers, performing complex root cause analysis of issues causing service interruptions, and a constant effort to automate and improve regular operations tasks.

  • Hosthealth Service
    • Designed, built, and maintained the hosthealth monitoring service that monitors and reports the health of all hypervisors.
    • Streamed metrics from hosts instead of requiring hosts to be polled regularly.
    • Used monitoring data to create alarms that helped meet a 15 minute SLA for compliance violations.
    • Setup data visualization aids for quick insite into the health of the hypervisor fleet.
    • During initial rollout, the hosthealth service provided the first alarm for a major compliance issues that had gone unreported for almost 24 hours.
  • Canary Testing Framework
    • Designed, built and maintained a test framework for writing canary tests on my own initiative.
    • Significatly reduced the effort required to expand production test coverage.
    • Significatly reduced the computing resources required to run tests.
  • Microcontainer image
    • Designed and implemented the build and deployment process for the microcontainer image that runs all VMs.
    • Coordinated the effort to get up to date custom slimmed down version qemu from the Oracle Linux team in California.
  • In-place kernel updates
    • Introduced support for in place kernel updates as part of the regular hypervisor release.
    • Used a product called KSplice, owned by Oracle, to apply updates to the host kernel while the system is running.
    • Illimitated the need to reboot hosts effected by issues with the host's kernel.
  • Other Accomplishments
    • Helped support the growth of the service from ~1000 hypervisors to almost 30,000k hypervisors
    • Helped plan and execute the effort to implement full end to end CI/CD for the VMI dataplane hypervisor stack.
    • Acted as release coordinator for a number of hypervisor deployments.
    • Root caused, fixed, tested and deployed fix during a full team emergent fleet wide patching effort that was preventing patching for the last 6% of the fleet.
    • Contributed regularly to various operations tools.
    • Assisted in acquiring workstations and laptops for the VMI dataplane team that were capable of running the hypervisor test stack.
    • 11th member of the OCI VM team which has grown to over 100 engineers.
December 2013 - June 2017
Strongbark Inc. - Chicago, Illinois
Technical Director

Provided Architecture, Development, System Administration, DevOps, and Management services to a Chicago based startup. Working primarily on a product called INESQUE, a social shopping network.

  • Designed & Built
    • Web front end using Microsoft ASP.NET MVC, Bootstrap, Knockout.js, and a custom single page framework.
    • API used by both a mobile application and the web front end using Microsoft ASP.NET Web Api.
    • Data access layer using Mongo DB and C#
    • Data aggregation service for collecting product information from various affiliate advertising networks.
    • Image and video management using Microsoft Azure cloud storage, and Azure Media services for video processing/encoding.
  • Managed
    • All DevOPS for the company. Jenkins, Hg, NuGet, OctopusDeploy, Azure, CI/CD
    • Integration testing and Production environments in Azure
    • Internal IT infrastructure in the Chicago office.
    • Managed several consultants and independent contractors based in South Africa and Chicago.
June 2012 - January 2014
Banco Popular North America - Rosemont, Illinois
Application Developer/Analyst

As a full stack web developer, developed .NET web based and native windows applications that improved existing business processes throughout the bank.

  • Developed .NET web based and native windows applications that improved existing business processes throughout the bank.
  • Designed and implemented internal workflow platform that allowed applications to integrate with a unified portal for all workflow based applications.
  • Integrated internal workflow platform with existing IBM product Teamworks, which allowed all internal applications company wide to be accessed from one portal.
  • Helped develop uniform APIs and client libraries for accessing various bank and customer information.
  • Spearheaded many small POC projects. Including, but not limited to:
    • Using Image recognition libraries to scan large document batches for barcodes.
    • Creating API to expose internal organization wide document management solution.
    • Integrating Single Sign On using Windows authentication to authorize users on Teamworks, the IBM business process modeling and workflow platform.
    • Using google location services to create a branch locator tool for all Banco Popular bank branches in North America.
November 2011 - June 2012
Geneca - Oak Brook, Illinois
Software Engineer

Worked as a consultant developing web applications using common web technologies and the .NET framework.

  • Worked as a consultant for multiple clients doing full stack web and mobile development.
  • Gained experience working as a consultant, and dealing with the struggles of consulting and working with difficult clients.
April 2011 - November 2012
Banco Popular North America - Rosemont, Illinois
Application Developer

Developed .NET web based and native windows applications that improved existing business processes throughout the bank.

  • Designed and implemented web-based and native windows applications using, WPF, Silverlight, ASP.NET, MVC, C#, JavaScript, JQuery, Entity Framework, WCF, and Restful web services with Web API and WCF.
  • Helped start more rigorous testing practices in the application development department.
  • Helped facilitate movement to more agile like development methodology.


Education

May 2011
Illinois Institute of Technology - Chicago, Illinois
Bachelors of Science in Information Technology and Management


Personal Interests

References are available upon request.