I am a Full Stack Developer and Mobile developer with 10+ years of experience, specializing in Python, React.js, Node.js, JavaScript, TypeScript, Swift, SwiftUI, Kotlin, React Native, Flutter and cloud services. I focus on clean architecture, scalability and user experience. I excel at managing projects, communicating with clients, identifying core issues, taking product ownership, mentoring juniors, and, above all, delivering systems that meet requirements and make users happy.

Robert Tessler

I am a Full Stack Developer and Mobile developer with 10+ years of experience, specializing in Python, React.js, Node.js, JavaScript, TypeScript, Swift, SwiftUI, Kotlin, React Native, Flutter and cloud services. I focus on clean architecture, scalability and user experience. I excel at managing projects, communicating with clients, identifying core issues, taking product ownership, mentoring juniors, and, above all, delivering systems that meet requirements and make users happy.

Available to hire

I am a Full Stack Developer and Mobile developer with 10+ years of experience, specializing in Python, React.js, Node.js, JavaScript, TypeScript, Swift, SwiftUI, Kotlin, React Native, Flutter and cloud services. I focus on clean architecture, scalability and user experience.

I excel at managing projects, communicating with clients, identifying core issues, taking product ownership, mentoring juniors, and, above all, delivering systems that meet requirements and make users happy.

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Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
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Language

English
Fluent

Work Experience

Guitar Teacher at Apprentus
January 1, 2025 - October 2, 2025
Teaching all ages classical, pop and jazz guitar. Also active in live sound recording and boom operator work, with involvement in film projects such as The Signal, Gateway to the Stars, A Parting Gift, and The Truth was Supposed to be out there. Maintains the YouTube channel guitarbasecamp and collaborates on recording and production projects using Cubase, Ableton Live and various VST plugins.
Founder at SixOfNine Engineering
July 1, 2025 - Present
Developing a suite of systems including a black-and-white to color image conversion service, an iOS mobile music player app, generative AI systems for 3D model creation and concert visuals, an embedded home automation system, a vocal replacement VST plugin, Three.js and Unity games, and related ML/AI software.
Full Stack Developer at Poolder
July 1, 2025 - October 14, 2025
Upgraded signup flow; created secure admin interfaces for monitoring and processing orders; added admin mode screens for system upgrades; enhanced data visualization charts; added buy and sell notifications and messaging functionality.
Mobile / Full Stack Developer at Sping
September 1, 2024 - October 14, 2025
Developed the QC One React Native mobile app for fruit and vegetable inspections (18,000 users); maintained HVG Tessa Android app in Kotlin; MVVM architecture with optimized async data loading; OCR and selective noise cancelling research; deployment via Fastlane and GitHub Actions.
Mobile / Full Stack Developer / Tech Lead at Sway Music
May 31, 2023 - October 14, 2025
Engineered cross-platform music streaming app for sharing playlists between Apple Music and Spotify; built with Flutter, Swift, SwiftUI and Kotlin; integrated Google Vision API and GCP; added notifications, chat, audio streaming, and real-time updates; admin portal in React.js; backend in Node.js / Python; deployed on Firebase.
Full Stack Developer at Twisted Rope
January 31, 2022 - October 14, 2025
Developed a JavaScript/React.js, D3.js web app for Accenture campaign data; updated Unity AR apps for iOS/Android; added features to the Legato concert booking system using React.js, PHP, MySQL and Laravel.
Full Stack Developer at Koda Design
July 31, 2021 - October 14, 2025
Developed a web app for APTC Fiji using Sitefinity CMS, C#, ASP.NET and .NET MVC; created iOS Swift app and React.js web app; API development in Firebase and GCP using Node.js, TypeScript; automated import of data into HubSpot using Python, Node.js and shell scripts; maintenance of Crescent Wealth API using Java, Spring Boot, Spring Data JPA, Kafka.
IOS Developer at KNAB
August 31, 2020 - October 14, 2025
Maintenance and development of the Knab banking app in Swift; redesigned signup process to simplify onboarding.
Mobile / Full Stack Developer at Sublime X
April 30, 2020 - October 14, 2025
Developed a mobile app in Flutter and admin site in React.js for Marine Rescue NSW to report marine hazards; used Firebase, Node.js backend, and GCP; deployed to iOS/Android.
Full Stack Developer at Saatchi & Saatchi
April 30, 2019 - October 14, 2025
Built an online hearing test web app for Cochlear; React.js frontend; Node.js REST API on AWS; integrated Salesforce, AWS S3, Lambda, API Gateway.
Front End Developer at Deloitte
July 31, 2017 - October 14, 2025
Relationship Access Manager system for the Australian Tax Office; built with Angular 2, MongoDB, Jasmine.js; Agile methodologies.
Full Stack Developer at Landsberry & James
September 30, 2016 - October 14, 2025
Web app for displaying advertising components and analytics; backend in C#, .NET MVC, .NET Web API; interactive ad data page builder; client work for Seven network.
Full Stack Developer at Publicis Groupe
June 30, 2013 - October 14, 2025
Developed intranet for AIHW; worked on .NET ASP sites: Unity Water, Better Electrical, Audi, Unilever; used C#, ASP.NET, .NET MVC, SQL Server, JavaScript, Backbone.js, jQuery.
Full Stack Developer at Devotion Digital
March 31, 2011 - October 14, 2025
Maintenance of ASP.NET multiple sites; Kentico CMS; updated wool.au website; used Java, J2EE, Spring and WebSphere.
Desktop App Developer at Deutsche Bank
December 31, 2005 - October 14, 2025
Created a derivatives trading Windows desktop app using MFC and C++; automated opportunity spotting and trading to improve trader productivity.
Desktop App Developer at STN Atas Electronic
June 30, 2000 - October 14, 2025
RAN Hydrographic Ship Project; data visualization, C++, Oracle, UNIX RPC, shell scripting.
Mobile / Full Stack Developer at Sping
September 1, 2023 - September 1, 2024
Development of the QC One React Native app for fruit and vegetable inspections serving 18,000 users. Added features to the HVG Tessa Android app for marine steel product inspections. Optimised data loading, coding in TypeScript, MobX, RealmDB, Sentry data logging, Jest unit and integration testing. QC One Inspector App; Android/iOS apps with Fastlane/CI-CD; research on selective noise cancelling with Python; energy usage calculator contributions; Agile processes.
Mobile / Full Stack Developer / Tech Lead at Sway Music
February 1, 2022 - May 1, 2023
Engineered a cross platform music streaming app for sharing playlists between Apple Music and Spotify. Built in Flutter, Swift, SwiftUI and Kotlin. Integrated Google Vision API and GCP; implemented push notifications, chat, audio streaming, and real-time updates. UI/UX driven by Figma; iOS/Android deployment; OAuth2; admin portal in React.js; cosine similarity text-based song matching; Firebase backend; API development (Node.js, Express.js, Python, FastAPI).
Full Stack Developer at Twisted Rope
July 1, 2021 - January 31, 2022
Optimised Accenture workflows by developing a JavaScript/React.js/D3.js web application for campaign data visualization from a SharePoint REST API. Updated Unity AR Reveryware and Pawpow apps for iOS/Android; added features to Legato concert booking system using React.js, PHP, MySQL and Laravel.
Mobile / Full Stack Developer at Koda Design
October 1, 2020 - July 1, 2021
Developed a web app for APTC Fiji using Sitefinity CMS, C#, .NET Core, ASP.NET; iOS Swift app and React.js web app for Pepsi Cola Taste Challenge; API development in Firebase and GCP; data import automation for HubSpot; maintenance of Crescent Wealth API (Java, Spring Boot, Redis, Kafka).
Mobile / Full Stack Developer at Sublime X
May 1, 2019 - April 1, 2020
Developed the MRNSW Risk App for Marine Rescue NSW; Flutter/React Native-based mobile/web app; Firebase backend; TypeScript, React, Redux, Swift; deployment to iOS/Android; PDF generation, GCP, OOP.
Full Stack Developer at Saatchi & Saatchi
March 1, 2018 - April 1, 2019
Built an online hearing test web app for Cochlear to help users assess hearing at home; frontend in React.js, JavaScript, Bootstrap; REST APIs with Node.js/Express hosted on AWS (S3, Lambda, DynamoDB, API Gateway).
Full Stack Developer at Landsberry and James
August 1, 2013 - September 30, 2016
Web app for displaying advertising components and analytics; backend in Java/Spring Boot, MySQL; interactive web page builder; ad data-driven pricing apps for Seven Network.
Full Stack Developer at Publicis Groupe
May 1, 2011 - June 30, 2013
Intranet for AIHW; enhanced .NET ASP sites; Unity/ multimedia trade-offs; multiple client-site enhancements across .NET stack.
Desktop App Developer at Deutsche Bank
January 1, 2000 - December 31, 2005
Created a derivatives trading Windows desktop app using MFC/C++; automated opportunities spotting and trader productivity improvements.
Desktop App Developer at STN Atas Electronic
November 1, 1997 - June 30, 2000
RAN Hydrographic Ship Project; data visualization of oceanographic data; C++, Oracle, UNIX RPC, shell scripting.
Mobile / Full Stack Developer at Twisted Rope
July 1, 2021 - January 31, 2022
Optimised Accenture workflows by developing a JavaScript, React.js, D3.js web application for campaign data visualization; updated Unity AR apps for iOS/Android; added features to Legato concert booking system; deployment to app stores.
Full Stack Developer at Devotion Digital
September 1, 2009 - March 31, 2011
Maintenance of ASP.NET sites; Kentico CMS; .NET C#; Java/J2EE, Spring, WebSphere; backend and frontend development.

Education

Bachelor of Science at Sydney University
January 11, 2030 - August 19, 2025
Ensemble - Jazz Guitar at Sydney Conservatorium of Music
January 1, 2013 - October 2, 2025
Jazz Piano Improvisation at Sydney Conservatorium of Music
January 1, 2008 - October 2, 2025
AMEB Piano Grade 4 at AMEB
January 1, 2005 - October 2, 2025
AMEB Classical Guitar Grade 5 at AMEB
January 1, 1989 - October 2, 2025
Classical guitar ensemble at Sydney Conservatorium of Music
January 1, 2015 - January 1, 2015
Jazz guitar ensemble at Sydney Conservatorium of Music
January 1, 2013 - January 1, 2013
Jazz piano improvisation at Sydney Conservatorium of Music
January 1, 2008 - January 1, 2008
Jazz guitar improvisation course at Sydney Conservatorium of Music
January 1, 1998 - January 1, 1998
AMEB Piano Grade 4 at AMEB
January 1, 2005 - January 1, 2005
AMEB Classical Guitar Grade 5 at AMEB
January 1, 1989 - January 1, 1989
Classical guitar ensemble at Sydney Conservatorium of Music
January 1, 2015 - October 2, 2025
Jazz guitar ensemble at Sydney Conservatorium of Music
January 1, 2013 - October 2, 2025
Jazz piano improvisation at Sydney Conservatorium of Music
January 1, 2008 - October 2, 2025
Jazz guitar improvisation course at Sydney Conservatorium of Music
January 1, 1998 - October 2, 2025
AMEB piano grade 4 at AMEB
January 1, 2005 - October 2, 2025
AMEB classical guitar grade 5 at AMEB
January 1, 1989 - October 2, 2025
Classical guitar ensemble at Sydney Conservatorium of Music
January 1, 2015 - January 1, 2015
Jazz guitar ensemble at Sydney Conservatorium of Music
January 1, 2013 - January 1, 2013
Jazz piano improvisation at Sydney Conservatorium of Music
January 1, 2008 - January 1, 2008
Jazz guitar improvisation course at Sydney Conservatorium of Music
January 1, 1998 - January 1, 1998
Graduate Certificate in Bioinformatics at Sydney University
January 11, 2030 - October 14, 2025
Honours in Computer Science at Sydney University
January 11, 2030 - October 14, 2025
BSc in Computer Science and Pure Mathematics at Sydney University
January 11, 2030 - October 14, 2025
Bioinformatics Graduate Certificate at Sydney University
January 11, 2030 - December 9, 2025
Computer Science Honours at Sydney University
January 11, 2030 - December 9, 2025
BSc Computer Science and Pure Mathematics at Sydney University
January 11, 2030 - December 9, 2025
Bioinformatics Graduate Certificate at University of Sydney
January 11, 2030 - December 20, 2025
BSc Computer Science and Pure Mathematics at University of Sydney
January 11, 2030 - December 20, 2025
Computer Science Honours at University of Sydney
January 11, 2030 - December 20, 2025
Bioinformatics Graduate Certificate at Sydney University
January 11, 2030 - December 20, 2025
Computer Science Honours at Sydney University
January 11, 2030 - December 20, 2025
BSc in Computer Science and Pure Mathematics at Sydney University
January 11, 2030 - December 20, 2025

Qualifications

Classical guitar ensemble
January 1, 2015 - December 31, 2015
Jazz guitar ensemble
January 1, 2013 - December 31, 2013
Jazz piano improvisation
January 1, 2008 - December 31, 2008
Jazz guitar improvisation course
January 1, 1998 - December 31, 1998
Bioinformatics Graduate Certificate
January 11, 2030 - August 19, 2025
AMEB Classical Guitar Grade 5
January 1, 1989 - October 2, 2025
BSc Hons Computer Science - Sydney University
January 1, 1986 - October 2, 2025
BSc Hons Computer Science
January 1, 1986 - October 2, 2025
AMEB piano grade 4
January 1, 2005 - January 1, 2005

Industry Experience

Software & Internet, Education, Agriculture & Mining, Manufacturing, Media & Entertainment, Computers & Electronics, Financial Services, Transportation & Logistics, Travel & Hospitality, Other, Professional Services, Telecommunications, Healthcare

Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
See more