John is available for hire
Hire JohnJohn Ginsberg
Verified Expert in Engineering
Full-stack Developer
Southend-on-Sea, United Kingdom
Toptal member since December 10, 2013
Bio
John is a developer, software architect, and entrepreneur with over 15 years of hands-on coding experience. He served as the CTO of a company that was acquired by a large fintech but is equally content working on smaller projects with great potential.
Portfolio
Klarna
Team Leadership, System Architecture, Amazon Web Services (AWS)...
Piggy (sold to Klarna)
Amazon Web Services (AWS), Vagrant, Redis, React, DevOps, JavaScript, PHP...
DSI
Ionic 3, Software Architecture, Software Development, Full-stack, REST APIs...
Experience
Availability
Full-time
Preferred Environment
MacOS
The most amazing...
...thing I've built is a real-time interactive analytics dashboard that updates its display every few seconds.
Work Experience
Domain Architect/Senior Engineering Manager
2021 - PRESENT
Klarna
- Assisted with the launch of numerous client-side (app and web) product experiences.
- Helped to establish architectural standards that further aligned the app, web, and browser extension products.
- Oversaw re-architecture of the browser extension as a platform to which dozens of feature teams now contribute.
Technologies: Team Leadership, System Architecture, Amazon Web Services (AWS), Technical Leadership, Domain Architecture, Enterprise Architecture, Web Marketing, React, TypeScript, Artificial Intelligence (AI), Next.js, Full-stack, REST APIs, Generative Artificial Intelligence (GenAI), LangChain, Retrieval-augmented Generation (RAG), Architecture, Chrome Extensions, API Integration
CTO
2014 - 2021
Piggy (sold to Klarna)
- Designed and architected the full technology stack.
- Built a Chrome browser extension that is actively used by more than 1 million users.
- Implemented and maintained a back-end infrastructure with 99.99% uptime.
- Created an affiliate tracking, reporting, and payment solution.
- Assisted with the evaluation and recruitment of team members.
Technologies: Amazon Web Services (AWS), Vagrant, Redis, React, DevOps, JavaScript, PHP, Technical Leadership, Software Architecture, Cloud Architecture, CTO, Software Development, Enterprise Architecture, Team Leadership, Next.js, Tailwind CSS, Full-stack, REST APIs, Architecture, Chrome Extensions, API Integration
Developer
2017 - 2017
DSI
- Built a simple Ionic app that integrates with Zendesk, across both iOS and Android platforms.
- Customized Cordova plugins.
- Enabled push notifications and built a simple web-based UI for sending.
Technologies: Ionic 3, Software Architecture, Software Development, Full-stack, REST APIs, API Integration
Developer
2017 - 2017
Silverback IS
- Built an Ionic application for Android.
- Integrated with various hardware devices via custom Cordova plugins.
- Wrote to remote PouchDB server via local CouchDB library.
Technologies: CouchDB, Ionic, Software Architecture, Software Development, Full-stack, REST APIs, API Integration
Developer
2016 - 2017
Pacific Islands Forum Fisheries Agency
- Built a hybrid iOS and Android application using Ionic 2 and subsequently Ionic 3.
- Enabled offline use and automated online sync of data when connected.
- Synchronized with various third-party and custom APIs.
Technologies: CouchDB, Ionic 3, Ionic 2, Software Architecture, Software Development, Full-stack, REST APIs, API Integration
Lead Developer
2014 - 2014
SynMedia
- Implemented a mobile app development framework based on Ionic and AngularJS.
- Created a mobile app builder and CMS.
- Integrated with third-party services like PhoneGap Build, Google Maps, and Pushwoosh.
- Deployed apps via Testflight.
- Designed an app experience that can be changed in real time via SaaS-based CMS.
Technologies: MySQL, JSON, PHP, JavaScript, Google Maps, Pushwoosh, PhoneGap, Ionic, AngularJS, Software Architecture, Software Development, Full-stack, REST APIs, API Integration
PHP Developer
2013 - 2014
Zendesk (via Toptal)
- Created a PHP wrapper library around the existing REST APi.
- Wrote a test suite for each endpoint.
- Implemented the PSR-0 standard.
- Integrated with and implemented a composer package.
- Implemented OAuth2 authentication.
Technologies: PHP 5, Software Development, Full-stack, REST APIs, API Integration
Product Director
2000 - 2013
Ensight
- Built an email and SMS delivery engine employing parallel processing and job queues to increase send speed while intelligently managing load at the server level. Created using PHP and shell scripting.
- Developed a social media management and publishing platform featuring integration with Facebook, Twitter, and Klout. The system downloads and calculates daily performance statistics and creates a PDF “social infographic” report. The report is designed using HTML5/CSS3, and creates a PDF using a headless browser (PhantomJS).
- Created a real-time campaign dashboard dynamically updating its display every 5-10 seconds to show users up to date statistics. Used PHP to load and cache results in real time (including unique user counts) and jQuery to serve data to the screen.
- Built a dynamic form builder allowing users to create forms with any number of fields, capture data, filter entries, and even target those entries for campaigns. Allowed the form builder to handle suppression management, validity checking, and automated cleanup of spam entries. Used PHP, MySQL, and a bit of JavaScript for the UI.
- Developed a background job processor built entirely using PHP and XML for management of scheduled and automated tasks.
- Developed a product currently used by hundreds of organizations and millions of end users across a wide range of industries, including retail, travel, financial services and utilities. Oversaw the production of over 4 major releases and hundreds of minor releases and updates.
- Created and deployed all supporting marketing and sales materials for the product, including websites, white papers, and user guides.
- Ran face to face and online (webinar) training programs for hundreds of users across dozens of client groups.
Technologies: Shell Scripting, CSS, HTML, PHP, JavaScript, Technical Leadership, Software Development, Full-stack, API Integration
Experience
MTNfootball.com
Built the site and back-end management interface, allowing for capturing of all content, scores, and match updates in real time, with distribution across web, mobile app, social media and SMS. Handled a large scale rollout during the 2010 World Cup, and have been supporting half a million users per month ever since.
Flash to HTML Conversion
In this project, I converted an app from Flash to JavaScript, ensuring pixel-perfect accuracy, using jQuery and HTML5 Canvas. The converted app has also been adapted to provide full support for mobile devices.
To-do App
Built a to-do list manager that allows users to create, organize, and manage tasks or items on a list. It uses Backbone.js on the front end, communicates with a REST back end, and was created exclusively using HTML, JavaScript, and PHP.
Skills
Libraries/APIs
jQuery, Zendesk API, REST APIs, React, Node.js, X (formerly Twitter) API, Backbone.js, Facebook API, jQuery UI, Pushwoosh, Google Maps, HTML5 Canvas
Tools
AWS SDK, Amazon Simple Queue Service (SQS), Vagrant, Git, Zend Studio, Atom
Languages
HTML, JavaScript, PHP, HTML5, SQL, CSS3, CSS, PHP 5, Bash Script, Bash, C, TypeScript
Platforms
Amazon EC2, AWS Lambda, MacOS, Linux, Windows, Amazon Web Services (AWS), NetBeans, iOS
Storage
Amazon S3 (AWS S3), Microsoft SQL Server, MySQL, JSON, Redis, CouchDB, PostgreSQL
Frameworks
AWS HA, Bootstrap, Ionic, Ionic 2, Next.js, Tailwind CSS, Ionic 3, AngularJS, PhoneGap, Zend Framework
Paradigms
Iterative Programming, DevOps, Test-driven Development (TDD), Agile Software Development, Load Testing, REST
Other
Technical Leadership, Software Architecture, Cloud Architecture, CTO, Software Development, Team Leadership, Domain Architecture, Enterprise Architecture, Full-stack, Architecture, Chrome Extensions, API Integration, Slackbot, Bots, Artificial Intelligence (AI), Generative Artificial Intelligence (GenAI), Retrieval-augmented Generation (RAG), Shell Scripting, UI Testing, System Architecture, Web Marketing, LangChain
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