toptal.com
Contact us: +1.888.604.3188
Ohad Kravchick, Application Security Developer in Santa Clara, CA, United States
Ohad Kravchick

Application Security Developer in Santa Clara, CA, United States

Member since September 7, 2018
Ohad has more than 15 years of experience building complex back-end, front-end, networking, and mobile systems. He focuses on building scalable, highly maintainable and testable systems, and debugging and maintaining high-availability of services. He takes pride in growing teams of capable engineers.
Ohad is now available for hire
Hire Ohad

Portfolio

Experience

  • Code Refactoring 15 years
  • Application Security 15 years
  • Debugging 15 years
  • Code Review 15 years
  • Java 12 years
  • System Design 12 years
  • JavaScript 8 years
  • Team Mentoring 8 years

Location

Santa Clara, CA, United States

Availability

Part-time

Preferred Environment

Linux, bash, vim, IntelliJ, git

The most amazing...

...under-the-hood infrastructure work I did was to upgrade Google Inbox/Gmail codebase from an arcane Java-to-JS compiler, mostly singlehandedly

Employment

  • Web Infrastructure Software Engineer

    2017 - 2018
    Coursera
    • Led the growth team.
    • Built, scaled, and tested a few isomorphic high-throughput React.js web apps.
    • Improved developers' tool set for flow.js and webdriver.io.
    • Built a new, flexible multi-step onboarding workflow.
    Technologies: React.js, Flow.js, Webdriver,io

  • Web Infrastructure Software Engineer

    2016 - 2017
    Google, Apps, Gmail and Inbox
    • Integrated a new Java→EcmaScript 6 transpiler.
    • Refactored Java code to adhere to Java subset suitable for transpiler.
    • Refactored JavaScript code to support ES6 and JsClosure’s modules.
    • Technically led a sub-team of four engineers during integration.
    • Developed low-level JavaScript benchmarking of output of new transpiler in preparation to support Inbox.
    • Coded many automatic source→source conversion tools in Python and bash.
    Technologies: Java, JavaScript, EcmaScript 6, Python, Bash

  • Senior Software Engineer

    2013 - 2015
    Google, Ads, DoubleClick for Publishers
    • Supported a real-time, billion-dollar ad delivery system, mostly in Java.
    • Created Google’s next video advertisement platform.
    • Technically led a team of five front-end engineers.
    • Built a scalable back-end system to support millions of customers.
    • Wrote Java code and tests to extremely high standards.
    • Debugged and profiled production issues.
    • Designed many upcoming features and future integrations.
    Technologies: Java, GWT, BigTable, MySQL

  • Mobile Software Architect

    2011 - 2013
    The New York Times
    • Designed and developed the NYTimes’ HTML5 single-page web-app (app.nytimes.com) using HTML5, JavaScript ES5, and CSS3. I worked on this project from the very beginning and was a central part of the coding, launch, as well as ongoing support and maintenance.
    • Designed and developed the NYTimes’ next mobile website (in-progress) on Node.js using CoffeeScript, dust templates, LESS.
    • Designed and led the development of an A/B testing tool for www.nytimes.com.
    • Wrote automatically testable code using mocha, sinon.js, JSCoverage, and Silenium+JS Driver.
    • Wrote highly maintainable code broken into NPM modules, MVP, and UI components.
    • As an architect, I led developers in my group technologically using brainstorming sessions, code reviews, peer programming, and demos.
    • Introduced and implemented back-end cutting-edge technologies: node.js, Redis, varnish, grunt.
    • Experienced with the latest front-end features – offline web applications, CSS3 transformations and transitions, local storage, WebSQL, and libraries – jQuery, Require.js, Backbone.js, Ext.JS / ST, and others.
    • Launched a new, innovative HTML5 product in a timely fashion with no technical problems.
    Technologies: Node.js, JavaScript, CoffeeScript, HTML5, CSS3, mocha, sinon.js, JSCoverage, Silenium, Redis, grunt

  • Lead Mobile Application Developer

    2010 - 2011
    Reuters
    • Developed and supported Reuters’ native iOS apps: “News Pro for iPhone” and “News Pro for iPad”; embedded external SDKs; debugged crashes; fixed bugs.
    • Designed, prototyped, led, and developed an entirely new content-driven HTML5 and JavaScript single-page web-app, using JavaScript, HTML templates, JQuery, CSS3, batched content delivery, offline caching, local storage caching, WebSQL, simple CMS, and multiple devices layouts.
    • Helped raise Reuters’ app rating from 3 to 4.5 by tackling and fixing long-time problems and crashes.
    • Maintained scalable back-end web services using Apache, Tomcat, JDBC, and memcache.
    • Acted as technical liaison between business developers, product managers, designers, editors, analysts, ad-ops, and third party providers, and the rest of the dev team (partly offshore).
    Technologies: Objective-C, HTML5, CSS, JavaScript, Apache, Tomcat, JDBC, Memcache

  • Professional Services Team Lead

    2009 - 2010
    Expand Networks
    • Generated revenue for Expand Networks by providing technical services to customers.
    • Developed Java applications and patches to reduce response time for customers.
    • Exclusively handled and executed all training of clients about Expand Networks’ products.
    Technologies: Java, Networking

  • Network Instructor and Engineer

    2000 - 2006
    IDF
    • Trained about 30 new recruits in networking using lectures, tests, CBTs, and recorded videos.
    • Designed and implemented several new protocols in a large-scale network (100+ routers): routing protocols, multicast, and redundancy protocols.
    • Maintained a large-scale network of routers, switches, WAN, and Firewalls.
    • Proficiency with computer networks: TCP/IP, Ethernet and VLAN switching, IP, routing protocols, TCP and UDP, common applications, redundancy protocols, security, multicast, WAN.
    Technologies: Networking, IP networks, Security, TCP/IP, Ethernet and VLAN switching, IP, routing protocols, TCP and UDP, common applications, Redundancy protocols, Security, Multicast, WAN

  • Co-Founder and Lead Web Developer

    1998 - 2000
    Bono Pie Israel
    • Founded, coded, and maintained a website with about 100,000 members.
    • Led a team of three web front-end and back-end developers.
    • Programmed a secured and scalable website in ASP (VBScript), SQL, JavaScript, Flash ActionScript, and Java applets.
    • Managed large-scale MS-SQL server set using SPs, indexes, and profiling.
    • Managed large deployment of IIS web servers.
    Technologies: ASP, MS-SQL, JavaScript, Flash ActionScript, Java applets, SQL

  • Programmer

    1996 - 1998
    Dolphin Ore LTD
    • Coded in VB, ASP, Access, and SQL.
    Technologies: VB, ASP, MS-SQL, Access

Experience

  • Reuters News Pro App (Development)
    https://itunes.apple.com/us/app/reuters-news/id602660809?mt=8

    Designed, prototyped, led, and developed an entirely new content-driven HTML5 and JavaScript single-page web-app, using JavaScript, HTML templates, jQuery, CSS3, batched content delivery, offline caching, local storage caching, WebSQL, simple CMS, and multiple devices layouts.

Skills

  • Languages

    Java, JavaScript, Bash Script, CSS, Python, SQL

  • Libraries/APIs

    React, Node.js, jQuery, RxJava

  • Paradigms

    Testing, Unit Testing

  • Other

    Debugging, Code Review, Code Refactoring, Code Architecture, Front-End Developer, UI Testing, API Testing, Network Security, API Design, IP Networks, Team Mentoring, Code Deployment, System Design, Application Security, HTTP

  • Platforms

    JVM, Linux

  • Frameworks

    AngularJS, Bootstrap, React Native, Jersey, Vert.x

  • Tools

    JavaScript Testing, JavaScript Debugging

  • Storage

    MySQL

Education

  • Master's degree in Computer Science
    2009 - 2012
    Fordham University - Bronx, NY
  • Bachelor's degree in Computer Science
    2003 - 2006
    The Open University - Ra’anana, Israel
  • Associate's degree in Electrical Engineering
    1999 - 2000
    Amit Amal Vocational School - Rishon Lezion, Israel

To view more profiles

Join Toptal
I really like this profile
Share it with others
Hire the top 3% of freelance developers TM