Robert is available for hire

Robert Tessler

Verified Expert in Engineering

Full-stack Developer

Delft, Netherlands

Toptal member since October 14, 2019

Expertise

CSS JavaScript HTML5 jQuery Express.js React.js Node.js Git MySQL Full-stack C++SQL GitHub Sitefinity

Bio

Robert is a mobile and full-stack developer who has worked across multiple industries, including digital media, finance, engineering, and manufacturing. He enjoys implementing elegant coding solutions to complex problems using imagination and the right choice of architecture and technology.

Portfolio

Sping

Kotlin, React Native, TypeScript, Java, Python 3, Android Studio, XC, Git GUI...

Sway Music

Flutter, Swift, Kotlin, Node.js, Firebase, iOS, Android, Git, CSS, HTML5...

Twisted Rope

JavaScript, SharePoint, Unity, Android, iOS, PHP, Laravel, HTML, React, PHP 7...

Experience

JavaScript - 8 years
React - 3 years
Node.js - 3 years
Flutter - 3 years
Swift - 1 year
Python 3 - 1 year
Firebase - 1 year
TypeScript - 1 year

Availability

Part-time

Preferred Environment

JavaScript, React, Node.js, Flutter, Swift, TypeScript, Python 3

The most amazing...

...things I've accomplished in my career include creating a web-based dashboard builder and charting the ocean floor using sonar readings.

Work Experience

Mobile Developer

2023 - 2024

Sping

Developed and maintained the QC One app for fruit and vegetable inspections. Added mobile functionality to their tablet app to open the app to more users.
Built and maintained the HVG Tessa Android app for steel product inspections. I significantly improved server sync times so inspectors could do their job faster.
Worked on the OCR app for reading text from images using Tesseract, Python, and Google Vision API.
Organized meetings and presentations and focused on agile sprint planning.

Technologies: Kotlin, React Native, TypeScript, Java, Python 3, Android Studio, XC, Git GUI, Agile

Mobile and Web Developer

2022 - 2023

Sway Music

Played back audio streams from multiple music providers.
Worked on native development in Flutter channels to make use of Apple Music and Spotify libraries.
Enabled real-time updates, notifications, social media integration, and chat functionality.
Implemented two Firebase cloud servers using Node.js, Express.js, and JavaScript.
Utilized the Google Vision machine learning API and developed a React admin web application.

Technologies: Flutter, Swift, Kotlin, Node.js, Firebase, iOS, Android, Git, CSS, HTML5, AVFoundation, Zeplin, GitHub, Xcode, Android Studio, Google APIs, HTML, Figma, React, Visual Studio Code (VS Code), CSS3, Python 3, DigitalOcean, SwiftUI

Web Developer

2021 - 2022

Twisted Rope

Developed a React and D3.js app for Accenture to display a graph of campaigns. This was a great help to Accenture project planning.
Built AReveryware and pawpow, Unity augmented reality apps for iOS and Android.
Worked on the Legato concert booking system using React, Laravel, and PHP.

Technologies: JavaScript, SharePoint, Unity, Android, iOS, PHP, Laravel, HTML, React, PHP 7, Git, Visual Studio Code (VS Code), Composer, Laravel Homestead, HTML5, Vagrant, CSS, GitHub, CSS3

Full-stack Developer

2020 - 2021

Koda Design Australia

Built an iPad survey progressive web application and an admin website for Pepsi Cola using React, Firebase, Node.js, MUI, and JavaScript.
Developed a website for Australia Pacific Training Coalition (APTC). The software was written using Sitefinity CMS, C#, MVC, and IIS.
Created the School of Performing Arts website using PHP, MySQL, and Apache.
Imported data into HubSpot using Python for Crescent Wealth.

Technologies: MySQL, PHP, MongoDB, GraphQL, Firebase, Node.js, ASP.NET, Sitefinity, MVC Razor, C#, Material UI, Progressive Web Applications (PWAs), Shell Scripting, Full-stack Development, React, Git, Visual Studio Code (VS Code), HTML5, Python, CSS, GitHub, CSS3

iOS Developer

2020 - 2020

Knab

Worked on the maintenance and new features for the Knab iOS app.
Attended meetings with developers and stakeholders to establish target goals and architecture.
Worked on the sign-up, UI design, multi-screen data collection, and API modifications.
Implemented the Swift code to handle new API endpoints and display information in associated screens.

Technologies: Coordinator Pattern, Model View ViewModel (MVVM), Reactive Programming, Xcode, iOS, Swift, Git, GitHub, CSS3

Full-stack Developer

2019 - 2020

Sublime Australia

Developed a system for the Marine Rescue NSW for reporting marine hazards in New South Wales coastal waters using React, Firebase, and Flutter.
Used a Node.js server on a Google Cloud Compute Engine VM for handling third-party authentication. Used features included a static IP on Google Cloud, an SSL certificate, HTTPS port routing, and Google Cloud DNS.
Created the front end in React and Redux, connecting to a Firebase back end.
Utilized Firebase Firestore database and Firebase storage for images and PDF documents.
Made use of Firebase functions for creating image thumbnails, connecting to a Weatherzone API, a proxy for authentication, PDF generation, Sendgrid email API, and access to sunrise and sunset times API.
Developed a mobile app in Flutter for iOS and Android and used SQLite for offline storage.

Technologies: Flutter, Google Cloud, Firebase, Express.js, Node.js, Redux, JavaScript, HTML, React, Full-stack Development, Git, Visual Studio Code (VS Code), HTML5, CSS, GitHub, CSS3

Full-stack Web Developer

2018 - 2019

MercerBell

Built an online hearing test for Cochlear with the front-end development in React, accessing a Cochlear REST API and Marketo.
Wrote a Node.js/Express.js REST API for Toyota hosted on AWS. The API handled JSON uploads of car features and options from Toyota store kiosks and sent them to Salesforce.
Used Marketo to register new leads, record results, and initiate a call to action.

Technologies: Amazon Web Services (AWS), Marketo, Bootstrap, Express.js, Node.js, JavaScript, HTML, React, Full-stack Development, Git, HTML5, CSS, GitHub, CSS3

Web Developer

2018 - 2018

Helpwise

Built a wholesale order tracking system for Six Degrees Fashion using Angular and a web API/SQL Server back end. Six Degrees Fashion supplies local retailers with women's clothing made in China.
Developed a phone app for Surf Life Saving Association using Cordova.
Developed a website for a financial service council using Joomla CMS.

Technologies: SQL Server 2012, PHP, .NET, Jira, Git, Angular, HTML, SQL, HTML5, CSS, CSS3

Full-stack Web Developer

2018 - 2018

Nine Entertainment Company

Built a CMS-driven web page builder. The CMS allows graphic designers to generate complex web pages quickly. Web pages commonly included parallax scrolling, Google Maps, carousels, and animation.
Used WordPress as a headless CMS with React on the front end.
Included parallax scrolling, Google Maps, carousels, and animation in websites like KPMG, Star Wars, Stargazing, and Kumano.

Technologies: PHP, WordPress API, JavaScript, Redux, React, HTML, SQL, Full-stack Development, HTML5, MySQL, CSS, GitHub, CSS3

Web Developer

2018 - 2018

Helpwise

Built a wholesale order tracking system for Six Degrees fashion distributor using Angular 6. Six Degrees supplies local retailers with women’s clothing they have made in China. WEB API/SQL Server back end.
Developed a website for Financial Services Council using Joomla CMS.
Developing a phone app for Surf Life Saving Association using Cordova.

Technologies: PHP, Angular, HTML, HTML5, CSS, GitHub, CSS3

Front-end Web Developer

2017 - 2018

Big Tin Can

Worked on a customer-facing iPad app for T-Mobile USA for employee work scheduling and customer sign up.
Delivered a responsive design for tablet and mobile.
Set up back-end communication with the Big Tin Can Hub.

Technologies: Git, Webpack, TypeScript, React, HTML, HTML5, CSS, GitHub, CSS3

Full-stack Developer

2017 - 2017

Deloitte

Worked on the relationship access management system for the Australian Tax Office. The system would allow companies that offer taxation services to register with the ATO and clients of those companies to apply for services.
Monitored performance for high-volume transactions using JMeter.
Set up continuous integration and delivery using Jenkins.

Technologies: TypeScript, Node.js, MongoDB, Angular, HTML, Full-stack Development, CSS, GitHub

Full-stack Developer

2017 - 2017

Audinate

Worked on the Dante Domain Manager (DDM) system for managing networks of audio devices. All networked devices have Dante audio cards for digital audio transfer.
Developed a web app for displaying and defining a network of audio devices with Dante audio cards.
Defined back-end data objects in MongoDB and used Meteor.js to retrieve the back-end data.

Technologies: Bootstrap, Node.js, Meteor, MongoDB, React, HTML, Full-stack Development, HTML5, CSS, GitHub

Full-stack Developer

2016 - 2016

Terem Technologies

Rebranded and ported the Pago Payments "try before you buy" system for the American market. Pago Payments is a deferred payment system (pago-pay.com).
Interfaced with multiple external APIs, including Stripe, PayPal, Twilio, and Mailchimp.
Performed Amazon EC2 configuration and back-end code development in PHP.

Technologies: Amazon Web Services (AWS), Magento, Stripe, PayPal, Composer, Zend Framework, PHP, HTML, Full-stack Development, HTML5, CSS, GitHub

Front-end Web Developer

2013 - 2016

Landsberry & James

Created a .NET back end supplying JSON data through WebAPI servers via Ajax to single-page web apps.
Developed a web app for a display of television, print, and radio advertisement video, images, and details. For use by clients to develop advertising campaigns.
Developed an interactive HTML page builder linked to L&J data.
Developed a web app for Seven television network admin and advertisement spot pricing. Comprised three apps written in Backbone.js.

Technologies: C#, jQuery, Backbone.js, JavaScript, HTML, SQL Server 2012, HTML5, CSS

Web Developer

2013 - 2013

Creative Licence Digital

Developed an iPad app for tobacco sales representatives to present and collect information on customer preferences and transmit data for market analysis.
Developed a website for Cracka Wines using Backbone.js.
Worked on a responsive mobile app for Greys Online.

Technologies: jQuery, Node.js, MongoDB, Backbone.js, JavaScript, HTML, SQL, SQL Server 2012, HTML5, CSS

Front-end Web Developer

2012 - 2013

Incentivated

Wrote a mobile app for arrivals and departures at Luton airport.
Developed the Froglife Dragon Finder iOS app for reporting sightings of UK wildlife.
Created an iPad app for promoting the Tesco club card.

Technologies: jQuery, JavaScript, HTML, HTML5, CSS

Web Developer

2012 - 2012

Mass Media Studios

Added SEO features to the Betta electrical website. Wrote intranet using Ektron CMS for AIHW.
Wrote a microsite for Audi using JavaScript and Backbone.js.
Wrote a web survey and promotion pages for Unilever products. Added functionality to the Unity water site.

Technologies: Backbone.js, jQuery, Microsoft SQL Server, JavaScript, HTML, SQL, SQL Server 2012, HTML5, CSS

iOS and Web Developer

2011 - 2011

Randstad

Developed a mobile version of the Randstad website.
Developed a native iOS iPhone job search app using Objective-C.
Added new features to the Randstad website using .NET and Microsoft SQL Server.

Technologies: jQuery, JavaScript, C#, HTML, SQL, HTML5, CSS

Application Developer

2008 - 2010

Health Communication Network

Added new features and maintenance of Medical Director software.
Worked in a small team with a highly managed project schedule in an agile development environment.
Contributed to interface design, database design, electronic prescriptions, document handling, barcode generation, COM plugins, and localization.

Technologies: Microsoft SQL Server, C#, SQL

Software Engineer

2000 - 2005

Deutsche Bank

Developed applications for derivatives trading. The system is used internally by traders throughout the world.
Developed Windows user interfaces, including client-server communication between Windows clients and Unix servers using sockets, threads, and transfer of XML data.
Contributed to the whole SDLC, including specifications, object-oriented design, software development, UAT, documentation, and support.

Technologies: C++, Shell Scripting

Experience

Marine Rescue NSW

Developed a system for Marine Rescue NSW for reporting marine hazards in NSW coastal waters.

I built the front end in React and Redux, connecting it to a Firebase back end. I also worked on an iOS/Android app in Flutter. I used Node.js/Express server on Google Compute Engine to handle 3rd-party authentication.
Networking: static IP on Google Cloud Platform, SSL certificate installation, HTTPS port routing, and DNS.
Firebase: database, storage, functions for creating image thumbnails, connecting to the Weatherzone API, a proxy for authentication, PDF generation, and SendGrid email.

Saatchi & Saatchi

https://www.cochlear.com/au/en/home/diagnosis-and-treatment/diagnosing-hearing-loss/signs-of-hearing-loss-in-adults/take-a-hearing-quiz

Created a web app for online hearing tests.

The system allows people with severe hearing loss to do the test at home in their own time. Data was recorded via the Cochlear API, and results were given to the user at the test conclusion.

Landsberry & James

Developed a web app for displaying television, print and radio ad video, images, and details. Clients use the app to build advertising campaigns. I created an interactive web page builder linked to L&J data (iPort). I also developed a web app for the Seven television network to display advertisement spot pricing, comprised of three apps written in Backbone.js.

STN Atlas

Developed software for the RAN Hydrographic Ship Project (HSS). I used sonar technology to capture oceanographic information. I made use of UNIX RPC client/server communication. I also wrote GUI code using ICS BX for presenting live and pre-recorded data.

Education

2003 - 2003

Master's Degree in BioInformatics

Sydney University - Sydney, Australia

1986 - 1986

Bachelor's Degree with Honors in Computer Science

Sydney University - Sydney, Australia

1981 - 1983

Bachelor's Degree in Science

Sydney University - Sydney, Australia

Skills

Libraries/APIs

React, Node.js, jQuery, Google APIs, WordPress API, Stripe, Backbone.js, Laravel Homestead, Core Graphics

Tools

Git, Zeplin, GitHub, Android Studio, Webpack, Composer, Xcode, Sitefinity, Jira, Figma, Vagrant

Languages

CSS, HTML, JavaScript, HTML5, Swift, C#, C++, Python 3, SQL, PHP 7, Python, TypeScript, GraphQL, Kotlin, PHP, CSS3, Java, XC

Frameworks

Angular, Flutter, Express.js, ASP.NET, .NET, Redux, Material UI, Bootstrap, Zend Framework, MVC Razor, Unity, Core Data, Core Location, Laravel, React Native, SwiftUI

Storage

MySQL, SQL Server 2012, MongoDB, Google Cloud, Microsoft SQL Server

Paradigms

Reactive Programming, Model View ViewModel (MVVM), Agile

Platforms

iOS, Firebase, DigitalOcean, Marketo, Meteor, Magento, Amazon Web Services (AWS), Docker, Visual Studio Code (VS Code), Android, SharePoint, Salesforce, Windows, Oracle

Other

Coordinator Pattern, Full-stack Development, PayPal, AVFoundation, Progressive Web Applications (PWAs), Shell Scripting, Motif, RPC, Molecular Biology, Ray Tracing, Git GUI

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