Tomislav Krnic, Developer in Ghent, Belgium
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Tomislav Krnic

Verified Expert  in Engineering

Bio

Tomislav is a full-stack developer and designer with 20+ years of experience, specializing in unique mobile app and web solutions. A founder and co-founder of several businesses, he has delivered 50+ major projects, including impactful solutions for visionary founders with unique ideas. Since joining Toptal in 2012, Tomislav has focused on building practical, high-value applications, helping entrepreneurs bring problem-solving innovations to life.

Portfolio

MeaMate
Full-stack Development, React, React Native, APIs, Big Data, Location Services...
CityX Apps
Firebase, React Native, iOS, Android, React, APIs, Card Payments, Payment APIs...
Fishing Pro - Fishing App
React Native, Firebase, APIs, UX Design, UI Design, Full-stack Development...

Experience

  • Full-stack - 15 years
  • Firebase - 7 years
  • Mobile Applications - 7 years
  • React Native - 7 years
  • React - 7 years
  • ChatGPT - 2 years

Availability

Part-time

Preferred Environment

React Native, Firebase, Startups, Full-stack, React, UI Development, Web Development, Mobile/Web Project Management, Payment APIs, ChatGPT

The most amazing...

...thing is seeing people ordering food, paying bills, checking city news, and planning fishing trips—all with apps I built to simplify their lives.

Work Experience

Co-founder | Lead Developer

2024 - PRESENT
MeaMate
  • Built MealMate from scratch as a powerful SaaS platform for restaurants and point of sale (POS) providers, streamlining ordering, payments, in-store ordering, and delivery to solve operational challenges with custom technology.
  • Researched the current state of restaurants and bars, leveraging prior success, an award, and a notable exit in this market. Identified common challenges affecting non-global chain restaurants, revealing clear opportunities for improvement.
  • Designed the full architecture, brand identity, and logo, reflecting innovation and reliability, with a visual message emphasizing simplicity and efficiency to align with the platform's technical focus.
  • Created a iOS and Android mobile app in React Native and integrated it with Firebase to provide a comprehensive food ordering solution featuring location-based services, advanced menu options, payments, loyalty programs, and order tracking.
  • Built a comprehensive content management system (CMS) in React to give restaurants full control over their operations and enable POS providers to manage restaurant processes efficiently.
  • Designed and built a web-based restaurant terminal to accept and manage orders, track working hours, and provide information on available delivery personnel, ensuring efficient real-time management.
  • Built a comprehensive API solution with over 50 endpoints publicly available for POS providers, ensuring high security, validation processes, error tracking, and log analytics. The system operates in three modes: production, test, and development.
  • Developed an in-store ordering system, including repeat order and split bill features, with QR and NFC table sticker solutions, enabling customers to order inside the restaurant. It is the mobile app and a standalone web solution.
  • Developed modules for delivery tracking, payment integration, issue escalation, delivery time estimation based on real data, and various integrations to ensure full functionality. Collaborated with a colleague on this project.
Technologies: Full-stack Development, React, React Native, APIs, Big Data, Location Services, Payment APIs, Card Payments, HTML, API Design, GitHub, Apps, App Design, Technical Leadership, NoSQL, Node.js, App Store, Google Play Store

Founder

2019 - PRESENT
CityX Apps
  • 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 10 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.
  • Delivered the CityX app, a fully functional application available in stores. Many AI solutions have reduced the need for an oversized team. Quarterly growth is approximately 200%.
  • Utilized my skills, encompassing React Native, Firebase, React, Node.js, UI/UX, Google Cloud, payment solutions, tons of API integrations, and cloud functions.
  • Created an MVP app that serves as a solunar forecast for anglers and has an integrated map with the option of live streaming fishing and positions. With integrated AI, the application recognizes the type of fish from the photos.
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, Live Chat, Mobile Applications, ChatGPT, Full-stack Development, Artificial Intelligence (AI), OpenAI, App UI, App UX, UX Design, Azure, API Design, GitHub, Apps, App Design, Technical Leadership, NoSQL, App Store, Google Play Store

Full-stack Developer

2024 - 2024
Fishing Pro - Fishing App
  • Developed Fishing Pro, an app for anglers utilizing AI to predict fish activity based on solunar theory. The app offers real-time weather updates and a tracker for fishing spots, enhancing trip planning and improving results.
  • Developed an advanced system that tracks 15+ data points for accurate fish activity predictions. Implemented a fishing tracker that helps users log catches and optimize their trips, improving user engagement and app retention rates.
  • Launched Fishing Pro, generating several hundred dollars per month in subscriptions within the first months. Led the app's development from scratch, achieving rapid user growth and establishing a foundation for future expansion.
Technologies: React Native, Firebase, APIs, UX Design, UI Design, Full-stack Development, API Design, GitHub, Apps, App Design, Technical Leadership, NoSQL, Node.js, App Store, Google Play Store

Full-stack Developer - React Native Mobile

2023 - 2023
Yahn Enterprises, LLC
  • Developed a mobile application within the planned timeframe, from a client's idea into a fully functional product ready for user acquisition.
  • Performed full-stack development, UI/UX, and logo design.
  • Built the application with React Native and Firebase. The app is published in App Store.
Technologies: React Native, Firebase, iOS, Android, Mobile UI, Mobile UX, Startup Consulting, Full-stack Development, GitHub, Apps, App Design, Technical Leadership, App Store, Google Play Store

Full-stack Mobile Developer

2020 - 2022
Entrio
  • Developed a mobile app from Entrio, the most prominent Croatian event-ticketing company with over 1,200 events per year and over 280,000 tickets.
  • Built 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, Cross-platform, Mobile Applications, Full-stack Development, PostgreSQL, API Design, GitHub, Apps, App Design, Technical Leadership, NoSQL, App Store, Google Play Store

Co-founder | CTO and Full-stack Mobile Developer

2018 - 2020
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, Cross-platform, Mobile Applications, Full-stack Development, PostgreSQL, API Design, GitHub, Apps, App Design, Technical Leadership, NoSQL, App Store, Google Play Store

Co-founder and Senior Full-stack Developer

2015 - 2018
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, Live Chat, Mobile Applications, Full-stack Development, HTML, PostgreSQL, Azure, API Design, GitHub, Apps, Technical Leadership, App Store

Senior Front-end Developer

2012 - 2016
FragranceX
  • 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, Full-stack Development, HTML, PostgreSQL, GitHub, Technical Leadership

Senior Front-end Developer

2014 - 2014
LogoGarden
  • 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, Full-stack Development, HTML, PostgreSQL, GitHub, Technical Leadership

Senior Front-end Developer

2013 - 2013
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, Full-stack Development, HTML, PostgreSQL, GitHub

Front-end Developer

2012 - 2013
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, Full-stack Development, HTML, PostgreSQL, GitHub

Front-end Developer

2012 - 2013
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, Full-stack Development, HTML, PostgreSQL, GitHub

Senior Web Developer

2012 - 2012
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, Full-stack Development, HTML, PostgreSQL, GitHub

Owner, Senior Web Developer (Code and Design)

2001 - 2012
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, Full-stack Development, HTML, PostgreSQL, GitHub, Technical Leadership

Co-founder, Web Project Manager, Senior Developer

2009 - 2011
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, Full-stack Development, HTML, PostgreSQL, GitHub, Technical Leadership

Education

2001 - 2005

Bachelor's Degree in IT Engineering

Polytechnic University of Zagreb - Zagreb, Croatia

Skills

Libraries/APIs

jQuery, API Development, React, REST APIs, Mapbox API, Google Maps, Facebook API, X (formerly Twitter) API, Amazon FPS, Node.js, Google Maps API

Tools

Adobe Photoshop, ChatGPT, GitHub, Adobe Illustrator, Figma

Languages

PHP, HTML5, Sass, CSS, JavaScript, HTML, SQL, TypeScript, CSS3

Frameworks

React Native, Redux, Smarty

Paradigms

UX Design, Mobile Design, UI Design, Mobile Development, Cross-platform

Platforms

Firebase, Google Cloud Platform (GCP), Mobile, Mapbox, iOS, Android, Amazon Web Services (AWS), Azure

Industry Expertise

Web Design

Storage

JSON, MySQL, Firebase Realtime Database, PostgreSQL, NoSQL, SQLite

Other

Pixel Perfect, Graphic Design, Ajax, User Interface (UI), Icon Design, APIs, Web Development, Front-end, Front-end Development, User Experience (UX), Software Development, Full-stack, Startups, Card Payments, Payment APIs, Credit Card Processing, Design, Development, Scanning, Ticketing, Ticket Systems, Events, Event Ticketing, Minimum Viable Product (MVP), Web & Mobile Applications, Mobile App Development, Mobile UI, Mobile UX, Push Notifications, Mobile Applications, Startup Consulting, OpenAI, App UI, App UX, Full-stack Development, API Design, Apps, App Design, Technical Leadership, App Store, Google Play Store, Live Chat, Artificial Intelligence (AI), Maps, Unique Business Ideas, Big Data, Location Services, UI Development, Mobile/Web Project Management

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