Dathan Guiley, Java Developer in San Diego, CA, United States
Dathan Guiley

Java Developer in San Diego, CA, United States

Member since July 15, 2013
Dathan is a forward-thinking freelance CTO, software architect, developer, and leader with roots in effective software development. He has 25 years in the field and experience with in-house development and management work at top internet companies including Amazon, Netflix, Yahoo!, and Overstock. He has focused for the last eight years on consulting, development, and management for startups and challenging projects.
Dathan is now available for hire




San Diego, CA, United States



Preferred Environment

Amazon Web Services (AWS), Docker, Angular, Kotlin, Java, IntelliJ, AWS, SaaS

The most amazing...

...things I've coded are ad servers for high-traffic sites and a clean, performant inventory system for a large eCommerce site.


  • Full-stack Developer/Consultant

    2013 - PRESENT
    Toptal (Consulting)
    • Contributed to many products and projects for clients ranging from brand-new startups to larger enterprises.
    Technologies: NoSQL, Angular, Groovy, Scala, Java
  • Founder, Principal Consultant

    2012 - PRESENT
    PowerUp (Consulting)
    • Consulted on software development best practices, the agile process, and leadership.
    • Performed hands-on architecture, project planning, and development in Java and Node.js.
    • Implemented a data strategy involving big data, collection, metrics, and dashboarding.
    Technologies: NoSQL, Angular, Groovy, Scala, Java
  • CTO

    2013 - 2015
    • Set and executed technology strategy. AdGlue is an online advertising startup that targets ads to specific page content.
    Technologies: Amazon Web Services (AWS), Amazon Elastic MapReduce (EMR), Netty, Storm, AWS, Grails, Groovy
  • Software Development Manager

    2010 - 2013
    • Led the principal team of an eight-team effort to integrate Overstock in external marketplaces. This constituted Overstock’s most significant project and included a tight timeline and tough requirements.
    • Coded and developed an adoption strategy for the next generation inventory system.
    • Led a team in hot swapping critical aging pieces of an order processing pipeline.
    Technologies: Java
  • Senior Software Developer

    2009 - 2010
    • Worked as technical lead on a next-generation auction-based ad delivery platform.
    • Led technical tasks on an Amazon Advertising Network project. The project enabled delivery of targeted ads based on Amazon behavioral data for third-party websites.
    Technologies: Java
  • Senior Software Engineer

    2006 - 2008
    • Developed the Netflix Ad Server, a lightweight embedded ad server with sophisticated delivery control, targeting, and simulation.
    • Designed and implemented Netflix’s RulesEngine Framework, responsible for determining content to be displayed at the top of Netflix home pages.
    Technologies: Java
  • Senior Software Engineer

    2005 - 2006
    • Worked as technical lead for the presentation tier of Campaign Planning Tool (CPT), a web application used by the Yahoo sales team to create, validate, and commit advertising proposals.
    Technologies: Java
  • Senior Software Engineer - Navy Contract

    2002 - 2004
    Northrop Grumman IT
    • Led technical projects for the second-generation development of the MyWxmap weather data visualization web application. The app allowed meteorologists to view weather charts and analyze predictive weather model results.
    • Designed and implemented the UI for the Chemical Downwind Forecast (CDF) web application. The app was designed, implemented, and deployed in a three-week period to support troops in Iraq.
    • Developed Jabber Webchat (JWC), a web-based Jabber client providing a highly responsive chat interface using only HTML and cross-browser JavaScript.
    Technologies: Java
  • Software Architect and Engineer

    1998 - 2001
    Enterprise Broadcasting Corp
    • Led software development for a hybrid digital cinema/eCommerce prototype with kiosks at each seat supporting broadband content and feature presentations.
    • Developed an application enabling a Grass Valley Group (GVG) Profile Video Server to transmit SMPTE Time Code to IP clients, allowing for synchronization between video and application servers.
    Technologies: C++, Object Pascal, Delphi, Java
  • Software Developer

    1995 - 1998
    • Designed and implemented a virtual reality (VR) viewing engine using Delphi (Object Pascal), OpenGL for real time rendering, and LightWorks for radiosity rendering.
    Technologies: Object Pascal, Delphi, C++


  • CTO Mentor at CONNECT Accelerator San Diego (Other amazing things)

    CONNECT is an accelerator that provides executive level mentorship to startups preparing to seek funding and launching.

  • Toptal Mentor
    Dathan is a mentor in the Toptal Global Mentor’s Program. This program is a partnership between Toptal and General Assembly to provide high quality mentorship for students from minority and low income backgrounds who are looking to begin their careers as professional software engineers. Dathan shows commitment to diversity in tech by mentoring a General Assembly student every week for a year, covering everything from coding tips and tricks to advice on making it in the industry.


  • Languages

    Kotlin, SQL, Java, JavaScript, C++, Scala, HTML5, CSS3, Groovy, Delphi, Object Pascal
  • Frameworks

    Angular, Spring Boot, Spring, AngularJS, Jersey, Hibernate, Apache Struts 2, JPA, Grails, Storm, Netty
  • Libraries/APIs

    Java Servlets, Jackson, JMS
  • Tools

    Maven, IntelliJ IDEA, Amazon CloudFront CDN, Adobe Photoshop, Amazon Elastic MapReduce (EMR), IntelliJ
  • Paradigms

    API Architecture, REST, Microservices, SOA, Agile Software Development, Object-oriented Programming (OOP), Scrum, Test Automation, Service-oriented Architecture (SOA)
  • Industry Expertise

    eCommerce, Web Development
  • Storage

    Couchbase, MySQL, CouchDB, Oracle SQL, Cassandra, Memcached, NoSQL
  • Other

    Leadership, Full-Stack Developer, CTO, AWS, Ad Serving, Software Development, Front-end, Front-end Development, Lean Development, SaaS
  • Platforms

    Amazon Web Services (AWS), Linux, Docker, WordPress


  • Bachelor's degree in Computer Science (theoretical focus)
    1993 - 1996
    University of California at Santa Cruz - Santa Cruz, CA

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