Tomislav Krnic
Software Developer
Location
Ghent, Belgium
Toptal Member Since
October 12, 2012
Tomislav is a full-stack developer and designer with over 20 years of experience. He has recently focused on React Native mobile development and real-time databases. He has founded or co-founded six businesses with three successful exits. He prides himself on a proven record of building full solutions with tangible results.
Tomislav is available for hire
Hire TomislavPortfolio
CityX
Firebase, React Native, iOS, Android, React, APIs, Card Payments, Payment APIs...
Entrio
React Native, UI Design, UX Design, Firebase, Firebase Realtime Database, APIs...
Grga
Firebase, React Native, CSS, iOS, Android, Payment APIs, Credit Card Processing...
Experience
CSS - 15 yearsPHP - 15 yearsHTML5 - 15 yearsJavaScript - 8 yearsFirebase - 6 yearsReact Native - 6 yearsSass - 5 yearsjQuery - 5 yearsLocation
Availability
Part-time
Preferred Environment
React Native, Firebase, User Interface (UI), Startups, Unique Business Ideas, CSS, Full-stack, UI Design
The most amazing...
...ability I have is that I can turn a basic business idea into a functional and understandable project that users know how to use.
Work Experience
2019 - PRESENT
Founder
CityX
- Acted as the founder and CTO of CityX, a company specializing in smart city app solutions. The app is available in over 50 cities and 12 countries and has been translated into ten languages. The app consists of a collection of APIs and open data.
- Found answers to questions on how to make the biggest app in a smart city space. Brought the idea to life, including contributing to designing the system architecture, leading developers, and creating the entire UI/UX.
- t this moment CityX app is a fully functional application available in stores. Many AI solutions have reduced the need for an oversized team. Quarterly growth is approx 200%.
- Utilized my skills, encompassing React Native, Firebase, React, Node.js, UI/UX, Google Cloud, Payment solutions, tons of API integrations, and cloud functions.
Technologies: Firebase, React Native, iOS, Android, React, APIs, Card Payments, Payment APIs, Node.js, Mobile Design, User Interface (UI), User Experience (UX), Full-stack, UI Design, Google Cloud Platform (GCP), Mobile Development, Startups, Web & Mobile Applications, Cross-platform, Front-end Development, Mobile UI, Mobile UX, Mobile, Push Notifications, REST APIs, TypeScript
2020 - 2022
Full-stack Mobile Developer
Entrio
- Developed a mobile app from Entrio, the most prominent Croatian event-ticketing company with more than 1,200 events per year and more than 280,000 tickets.
- Developed a React Native application from scratch that was intended as a ticket scanner connected to a few servers with non-SQL and SQL databases.
- Contributed to developing the React Native application that consisted of multiple solutions, including communication between scanners, offline mode, and tons of logs. Event organizers could hire Entrio to ensure a smooth process.
Technologies: React Native, UI Design, UX Design, Firebase, Firebase Realtime Database, APIs, Scanning, Ticketing, Ticket Systems, Events, Event Ticketing, SQL, SQLite, Amazon Web Services (AWS), Google Cloud Platform (GCP), Figma, Mobile Development, Front-end Development, Mobile App Development, Mobile UI, Mobile UX, Mobile, Push Notifications, REST APIs, TypeScript
2018 - 2020
Co-founder | CTO and Full-stack Mobile Developer
Grga
- Worked on Grga, a mobile application for payment and ordering processes related to restaurants and bars. The app provides a solution for connecting to more than 50,000 cash registers. One solution enables users to make orders and pay with a QR code.
- Designed a system, created a mobile app and the UI/UX and connected with the payment gateway. Worked on it for a little over two years; millions were paid without any mistakes or wrong orders, and I have a reason to be satisfied with the project.
- Completed the project and after a successful exit, Grga still exists within a large multinational company.
Technologies: Firebase, React Native, CSS, iOS, Android, Payment APIs, Credit Card Processing, User Interface (UI), User Experience (UX), Full-stack, UI Design, Amazon Web Services (AWS), Google Cloud Platform (GCP), Mobile Development, Startups, Front-end Development, Mobile App Development, Mobile UI, Mobile UX, Mobile, Push Notifications, REST APIs, TypeScript
2015 - 2018
Co-founder and Senior Full-stack Developer
Touchmoon
- Created an application for Touchmoon, a demanding project that aimed to represent a new generation of mobile messengers. The application has multiple unique solutions and features like animations, strong security, and custom games.
- Created the functional UI/UX and the web part of the project.
- Delivered Touchmoon, the app had a good start, excellent reviews, and was mentioned in the media.
Technologies: React, React Native, PHP, MySQL, APIs, HTML5, CSS, Design, Firebase, User Interface (UI), User Experience (UX), Full-stack, UI Design, Amazon Web Services (AWS), Google Cloud Platform (GCP), Startups, Front-end Development, Mobile App Development, Mobile UI, Mobile UX, Mobile, Push Notifications, REST APIs
2012 - 2016
Senior Front-end Developer
FragranceX (via Toptal)
- Developed the front end and responsive design as my role for the project.
- Worked for FragranceX, one of the biggest US-based eCommerce stores. Every "pixel" on the web was important, and my focus on details came to the fore.
- Optimized the user interface and experience; developed the JavaScript front-end solutions and created a fully responsive web.
Technologies: HTML5, Sass, CSS, jQuery, JavaScript, User Interface (UI), User Experience (UX), Full-stack, UI Design, Front-end Development, REST APIs
2014 - 2014
Senior Front-end Developer
LogoGarden (via Toptal)
- Designed and developed the company website and improved the UI/UX for responsive websites.
- Utilized technologies, including HTML, CSS, jQuery, JavaScript, and Sass, for the project.
- Built LogoGarden, an online logo creation for your business with over 2.5 million custom logos made. Users can create their logos fast and for free.
Technologies: HTML5, Sass, CSS, jQuery, JavaScript, User Interface (UI), User Experience (UX), Full-stack, UI Design, Front-end Development
2013 - 2013
Senior Front-end Developer
Rock Lobby (via Toptal)
- Developed a custom CMS solution.
- Developed UI/UX elements using jQuery.
Technologies: MySQL, PHP, CSS, jQuery, JavaScript, HTML5, User Interface (UI), User Experience (UX), Full-stack, UI Design, Front-end Development
2012 - 2013
Front-end Developer
Rise Events (via Toptal)
- Developed four websites for this Washington D.C.-based real estate company.
- Designed four connected web pages based on the same style with small variations.
- Created a jQuery/GoogleMap system to display location on mouseover.
Technologies: Google Maps API, JavaScript, jQuery, CSS3, HTML5, Web Design, User Interface (UI), User Experience (UX), Full-stack, UI Design, Front-end Development
2012 - 2013
Front-end Developer
Eminent Domains/IMissYou (via Toptal)
- Created a strong and user friendly front-end with many jQuery features.
- Built a beautiful but technically complex layout with a combination of photos/videos/Twitter/Facebook/message and models put in masonry composition.
Technologies: JavaScript, jQuery, CSS3, HTML5, User Interface (UI), User Experience (UX), Full-stack, UI Design, Front-end Development
2012 - 2012
Senior Web Developer
Design Theorem/oMiami (via Toptal)
- Handled project finalization to solve problems with connecting scrolling events and pointing places on maps.
- Took care of various advanced CSS tasks.
Technologies: jQuery, HTML5, CSS3, User Interface (UI), User Experience (UX), Full-stack, UI Design, Front-end Development
2001 - 2012
Owner, Senior Web Developer (Code and Design)
Studio Cro-Design
- Created a photo community site independently with over 13,000 users in the Croatian photography community. Received numerous recognitions and included over 800 themed competitions. Looked into expanding the site to the US market.
- Created a B2B image sharing system for Mars, a large food distribution company. Designed initially for Mars Croatia, but later expanded to Mars Europe. Included automated image preparation, zip file creation, and download management.
- Developed a CMS for a real estate agency, including multi-language support and a best property search features.
- Wrote a fully automated system that used Expedia API for booking hotels and flights.
- Created a small corporate web page with a clean design displaying a simple, custom CMS and moderate use of jQuery and Flash.
Technologies: CSS3, HTML5, Ajax, jQuery, MySQL, PHP, User Interface (UI), User Experience (UX), Full-stack, UI Design, REST APIs
2009 - 2011
Co-founder, Web Project Manager, Senior Developer
iKiosk
- Developed a system independently for formatting and selling digital magazines, books, and newspapers. Won recognition from Forbes magazine as a great internet business project.
Technologies: CSS, Ajax, jQuery, CSS3, HTML5, MySQL, PHP, User Interface (UI), User Experience (UX), Full-stack, UI Design, Front-end Development, REST APIs
Experience
Touchmoon Messenger
📲 https://apps.apple.com/us/app/touchmoon-messenger/id998832220
A mobile messenger of the new generation. Really!
☞ Co-founder
☞ Front- and back-end services, app games, and many other things developed over 3+ years of hard work.
A mobile messenger of the new generation. Really!
☞ Co-founder
☞ Front- and back-end services, app games, and many other things developed over 3+ years of hard work.
Grga - Mobile Ordering and Payment App
http://grga.euA mobile payment app available in many cafes in Croatia.
I acted as the co-founder and full-stack mobile developer for a mobile payment app available in many cafes in Croatia. The application is in the top 10 of the App Store, with over 100 stores and 9,000 users.
TECHNOLOGIES AND APPLICATION CHARACTERISTICS:
• React Native
• Redux
• API
• Cash register connection
• Payment system (accepting all major credit cards)
• QR reader
• Firebase authentication, messages, analytics, function/back-end
• Notifications
• API Connect
• UI/UX
• App Store and Google Play
Apps.apple.com/hr/app/grga-tvoj-digitalni-konobar/id1439087229?l=hr
Play.google.com/store/apps/details?id=com.grga&hl=e
I acted as the co-founder and full-stack mobile developer for a mobile payment app available in many cafes in Croatia. The application is in the top 10 of the App Store, with over 100 stores and 9,000 users.
TECHNOLOGIES AND APPLICATION CHARACTERISTICS:
• React Native
• Redux
• API
• Cash register connection
• Payment system (accepting all major credit cards)
• QR reader
• Firebase authentication, messages, analytics, function/back-end
• Notifications
• API Connect
• UI/UX
• App Store and Google Play
Apps.apple.com/hr/app/grga-tvoj-digitalni-konobar/id1439087229?l=hr
Play.google.com/store/apps/details?id=com.grga&hl=e
Undiet Tracker
📲 https://apps.apple.com/us/app/undiet-tracker/id1490849895?ls=1
📲 https://play.google.com/store/apps/details?id=com.undiet&hl=en
An app, built in React Native, for weight loss motivation and tracking. I came up with the idea for the app, handled coding, and designed the UI/UX.
- React Native
- Redux
- Firebase DB/storage, authentication, messages, analytics, function/back end
- Notifications
- UI/UX
- App Store and Google Play
- Landing page
Development time: 25 days
📲 https://play.google.com/store/apps/details?id=com.undiet&hl=en
An app, built in React Native, for weight loss motivation and tracking. I came up with the idea for the app, handled coding, and designed the UI/UX.
- React Native
- Redux
- Firebase DB/storage, authentication, messages, analytics, function/back end
- Notifications
- UI/UX
- App Store and Google Play
- Landing page
Development time: 25 days
AirQuality and Weather Chat
📲 https://apps.apple.com/us/app/airquality-and-weather-chat/id1495791987?ls=1
☞ Air Quality cover more than 11,000 world stations in more than 1000 cities. Live data covers all relevant air quality information for all pollutants.
☞ Live weather data, 200,000 cities
☞ Chat, based on the nearest measuring station
- React Native
- Redux
- Firebase authentication, messages, analytics, function/back end
- Notifications
- API connect
- UI/UX
- App Store and Google Play
- Landing page
Development time: 20 days
☞ Air Quality cover more than 11,000 world stations in more than 1000 cities. Live data covers all relevant air quality information for all pollutants.
☞ Live weather data, 200,000 cities
☞ Chat, based on the nearest measuring station
- React Native
- Redux
- Firebase authentication, messages, analytics, function/back end
- Notifications
- API connect
- UI/UX
- App Store and Google Play
- Landing page
Development time: 20 days
Publication
Responsive Web Design Media Query Examples Explained
https://www.toptal.com/responsive-web/introduction-to-responsive-web-design-pseudo-elements-media-queries
Skills
Languages
PHP, HTML5, Sass, CSS, JavaScript, TypeScript, CSS3, SQL
Frameworks
React Native, Smarty
Libraries/APIs
jQuery, API Development, React, REST APIs, Google Maps, Facebook API, Twitter API, Amazon FPS, Google Maps API, Node.js
Tools
Adobe Photoshop, Figma, Adobe Illustrator, Adobe After Effects
Paradigms
UI Design, Mobile Development, Search Engine Optimization (SEO), Cross-platform, UX Design, Mobile Design
Platforms
Firebase, Google Cloud Platform (GCP), iOS, Android, Amazon Web Services (AWS), Mobile
Storage
JSON, MySQL, Firebase Realtime Database, SQLite
Other
Pixel Perfect, Ajax, User Interface (UI), APIs, Web Development, Front-end, Front-end Development, User Experience (UX), Software Development, Full-stack, Startups, Payment APIs, Credit Card Processing, Development, Minimum Viable Product (MVP), Web & Mobile Applications, Mobile App Development, Mobile UI, Mobile UX, Graphic Design, Icon Design, Push Notifications, Unique Business Ideas, Card Payments, Design, Scanning, Ticketing, Ticket Systems, Events, Event Ticketing
Industry Expertise
Web Design
Education
2001 - 2005
Bachelor's Degree in IT Engineering
Polytechnic University of Zagreb - Zagreb, Croatia