Senior JavaScript Developer
2019 - 2021LightStep (via Toptal)- Maintained the OpenTelemetry API in JavaScript for both Node.js and browser.
- Was one of the main contributors for developing OpenTelemetry JavaScript. Created many parts of OpenTelemetry, including tracing and metrics.
- Released stable tracing version 1.0 and experimental for metrics.
- Reviewed many PR from many different contributors.
- Created all main plugins for the web and also many plugins for Node.js.
- Created the most popular exporter, Collector Exporter for OpenTelemetry JavaScript for tracking and metrics.
Technologies: TypeScript, JavaScript, Node.js, AnalyticsSenior JavaScript Developer
2019 - 2020Infinity Lending Systems (via Toptal)- Created the front-end prototype for a new payment system using TypeScript, Angular 8, and Angular Materials.
- Created a standalone component for taking payments that can be embedded into any website.
Technologies: Azure, SQL, TypeScript, Angular Material, AngularReact Expert
2019 - 2019Reddit (via Toptal)- Created a video module for the admin panel for approving videos. The video module supported different filters, generating thumbnails without a back end.
Technologies: Canvas, Video Streaming, Redux, React, TypeScriptFull-stack Engineer
2018 - 2019FastSwims (via Toptal)- Built a working product from scratch to organize swimming competitions in the USA.
- Created a whole back end using Node.js and Sequelize.
- Created a front-end SPA using React, Redux, and Saga.
- Integrated with payment systems and Mixpanel analytics.
- Created converters for swimming results that comply with USA Swimming Data Interchange format.
- Created auto import of swimming results from an external web page.
Technologies: Amazon Web Services (AWS), Sass, PostgreSQL, Relational Database Services (RDS), Sagas, Redux, React, Sequelize, Node.jsSenior JavaScript Developer
2018 - 2018Video Chat- Created a Video.js plugin for WebRTC livestreaming video integrated with Wowza Servers.
Technologies: Video.js, Wowza, JavaScript, WebRTCSenior JavaScript Developer
2016 - 2018Castlabs- Created DOWNStream for Electron, an open-source project for downloading DASH movies.
- Created a desktop app for downloading movies based on Electron and React.
- Worked on ongoing development of PRESTOPlay for browsers.
- Implemented smooth streaming.
- Created a video tracking plugin for Video.js.
- Integrated analytics for "conviva" and "nice people at work."
- Implemented Chromecast sender and receiver.
- Created util for processing subtitles which were images using canvas and then to be able to change the color of subtitles.
Technologies: Encrypted Media Extensions (EME), Node.js, Electron, Video Streaming, JavaScriptFreelance Node.js Developer
2016 - 2016Slash-hyphen (via Toptal)- Added a few new features to a Slack bot.
Technologies: JavaScript, Node.js, Emacs, BotkitFreelance Senior JavaScript Application Engineer
2016 - 2016Placester (via Toptal)- Created a Node.js service for importing contacts.
- Created a new extendable modal.
- Integrated with Localytics.
- Created a module for partner scripts so that they can inject HTML fragments and custom scripts.
- Fixed many bugs and improved stability in the admin panel.
Technologies: Node.js, PHP, CSS3, HTML5, Less, Marionette.js, Backbone.js, JavaScriptOwner and Freelance Developer
2013 - 2016FIOBE- Developed an AngularJS app for file sharing.
- Worked on presentations for a mobile conference.
- Worked on video and audio streaming based on Node.js and DynamoDB.
- Worked on a document data flow app, using Node.js and AngularJS.
- Created a finance report and statistics web app using Node.js, AngularJS, PostgreSQL, and HighCharts.
- Worked on a new responsive web app for ING Bank Śląski using Marionette, Backbone, and Node.js.
Technologies: Python, Thymeleaf, Java, Linux, Git, jQuery, PHP, Bootstrap, Sass, CSS, HTML5, Bower, Gulp, Grunt, AngularJSFreelance Senior Front-end Developer
2014 - 2015ConsumerAffairs.com (via Toptal)- Created a vanilla JS library for for toggling and shuffling elements on the page.
- Improved the build process using Gulp, Jasmine unit tests, and documentation using JSDoc.
- Integrated with Segment.io and Mixpanel.
- Used a TypeForm to collect data about pet quizzes and then presented aggregated data on a custom SVG chart.
- Refactored campaign pages and brand pages.
- Optimized the generation of emails using improved SQL queries and stored procedures.
- Built a pure CSS solution for star ratings.
- Refactored the Ouibounce library (exit intent) to work on mobile, also adding some improvements.
- Integrated action forms.
Technologies: JSDoc, Typeform.io, Jinja, Branch.io, Highcharts, Bash, CircleCI, Karma, Jasmine, Mixpanel, Google Analytics, MySQL, Python, Django, Handlebars, Gulp, Backbone.js, AngularJS, Sass, Stylus, CoffeeScript, JavaScriptFreelance Developer
2014 - 2014FindTheBest (via Toptal)- Created a prototype app using AngularJS.
- Integrated with family search API using a third-party SDK.
Technologies: Bootstrap, AngularJS, JavaScriptCTO
2012 - 2013Starters- Created an HTML text editor in vanilla JS.
- Developed a web app for taking notes using PHP 5, JavaScript, and Python.
- Prototyped an e-learning platform using Java and HTML5.
- Prototyped using Mockflow.com.
Technologies: MySQL, PostgreSQL, Apache, Debian Linux, Git, jQuery, Python, PHP 5, JavaScript, CSS, HTML5Senior Engineer
2009 - 2012Nokia Gate 5- Worked on creating a route between points on a map using JavaScript.
- Developed a traffic data visualization and public transportation routing using JavaScript and REST.
- Developed Flying 3D, a simulator for any route, using JavaScript.
- Developed an interface for on-map weather information, using Java, Python, and JavaScript.
- Developed a build stats tool for Jenkins in Python.
- Tested with Jasmine, JBehave, and Cucumber.
- Applied continuous integration using Jenkins, Maven, and Puppet.
Technologies: Varnish, Splunk, Git, Subversion (SVN), Continuous Integration (CI), Puppet, Jasmine, JBehave, Behavior-driven Development (BDD), Test-driven Development (TDD), jQuery, Scrum, Agile, Maven, Python, Java, JavaScript, CSS, HTMLSenior Developer
2009 - 2009Web Solutions- Helped develop a search module for over 500 domains.
- Developed a multi-threading service for domain search using C# IIS.
- Developed an administration panel for office support.
- Developed a payment gateway with credit cards, using REST and C#.
- Used Mono framework.
Technologies: EPPlus, XML, SMTP, HTTP, Web Services, MySQL, C#, Visual Basic, Mono, ASP.NET, Visual Basic for Applications (VBA), Microsoft Visual Studio, Ajax, Test Cases, JavaScript, XHTML, Subversion (SVN), IIS, .NETTeam Leader
2007 - 2009Where Are You Now- Implemented a new mailbox using data migration, C#, and JavaScript.
- Developed geolocations—a map point and Google Maps—creating a new database for towns from all over the world.
- Developed contact imports from an address book, optimizing an existing mechanism.
- Implemented full search using Visual Basic and MS SQL.
- Developed Carbon Footprint, calculating the amount of GHG (greenhouse gas) emissions caused directly and indirectly by traveling around the globe.
- Developed Friends Book, a module for keeping in touch with friends. Implemented many changes and optimizations.
Technologies: XML, SMTP, HTTP, WSDL, Scrum, FTP, Web Services, CSS, Visual Basic 6 (VB6), OpenVPN, MySQL, ASP.NET, Microsoft SQL Server, ASP, Subversion (SVN), Ajax, SQL, JavaScript, XHTML, SOAP, IIS, .NETWeb Developer
2006 - 2007Where Are You Now- Worked on an integration with Virtual Earth and Google Maps, using JavaScript.
- Developed a trip profile page and a travel guide using JavaScript and CSS,.
- Worked on integration with third parties using web services and SOAP.
Technologies: XML, SMTP, HTTP, WSDL, FTP, Web Services, CSS, Visual Basic 6 (VB6), OpenVPN, MySQL, ASP.NET, Microsoft SQL Server, ASP, Subversion (SVN), Ajax, SQL, JavaScript, XHTML, SOAP, IIS, .NETOwner and Freelance Developer
2000 - 2007COBO- Developed a web application for document flows inside the company, using PHP, JavaScript, CSS, and Ajax.
- Built client/server applications for managing documents flows between architects, such as time sheets, costs, reminders, reports, LAN chat, and progress for each project, using Delphi and dBase.
- Created a data warehouse for a company which sells steel pipes. Used PHP, JavaScript, CSS, and MySQL.
- Programmed applications to generate statistics for the National Lottery. Used Delphi and dBase.
- Developed a client/server application for managing and controlling the computers in an Internet Café. Used Delphi, TCP/IP, and UDP.
- Built an application for managing a cemetery, using Delphi and dBase.
Technologies: dBASE, Apache, CSS, HTML, JavaScript, Ajax, MySQL, PHPSoftware Developer
2005 - 2006Agryf S.A. - Animex Group- Created reports with a custom app, implemented with Delphi, dBase, and Firebird.
- Made reports for various departments, using Delphi, dBase, Firebird, and Oracle 8i.
- Administrated the company network, using Novell, DHCP, and SSH.
- Developed a dedicated application for reading wages using Assembly, PASCAL, and dBase.
Technologies: SMTP, FTP, Assembler, Novell NetWare, XML, Pascal, Firebird, TCP/IP, Oracle, SSH, OpenVPN, DHCP, SQL, HTTP, DelphiSoftware Developer
2005 - 2005Public Hospital- Developed various small apps using Delphi and dBase.
- Performed server administration in Novell, UNIX, Oracle, and Informix.
- Developed the web page using JavaScript, CSS, HTML, MySQL, and PHP.
- Implemented a daily work scheduler using PHP, Delphi, MySQL, and JavaScript.
Technologies: CSS, HTML, JavaScript, PHP, Linux, IBM Informix, Unix, SMTP, FTP, Novell NetWare, TCP/IP, Oracle, Ethernet, SSH, OpenVPN, DHCP, SQL, HTTP, DelphiIT Technician, Software Developer
2001 - 2002Aeris Computers- Created web pages using JavaScript, HTML, and CSS.
- Built new workstations.
- Helped with computer software and harder IT tasks.
- Developed a desktop app for updating warehouse, in Delphi and MySQL.
Technologies: CSS, HTML, JavaScript, PHP, SQL, Delphi