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Kristina Grujic
Verified Expert in Engineering
Software Developer
Novi Sad, Vojvodina, Serbia
Toptal member since July 16, 2020
Bio
Kristina is a passionate front-end engineer with 10 years of experience specializing in React and React Native projects. Her valuable input and development skills on the IoT product AirThinx won the New Product Innovation award in 2019 by Frost & Sullivan and the Top Project award in 2018. She has led technical projects and mentored colleagues. Kristina is known for delivering clean and maintainable, high-quality code delivered with fast turnaround times.
Portfolio
MotionOps
React, React Native, React Hook Form, Redux, Mobiscroll, Calendars, Expo...
Netronix
Agile, Git, Android Studio, Xcode, Enzyme, Appium, Jest, Redux-Saga, Redux...
Elligencia
React, React Native, Chart.js, SVG Animation, Expo, Tailwind CSS, Next.js...
Experience
- Git - 12 years
- CSS - 11 years
- JavaScript - 11 years
- Redux - 10 years
- React Native - 10 years
- React - 10 years
- Jest - 4 years
- GraphQL - 3 years
Preferred Environment
Slack, Visual Studio Code (VS Code), MacOS
The most amazing...
...IoT product I drove was AirThinx, an air quality monitor. It won the New Product Innovation (2019) and the Top Project (2018) award by Frost & Sullivan.
Work Experience
Lead Front-end Developer
2023 - PRESENT
MotionOps
- Developed a photo annotation tool from scratch, allowing brush, text, and shape annotations in various colors, sizes, and opacities in the mobile app.
- Built a new camera based on an expo camera with photo and video taking, extensive settings, and display of spirit level, grids, location, and time stamps in the mobile app.
- Created schedule and timesheet functionalities with fully custom calendars and timeline/agenda functionality.
- Refactored most of motionops web application, providing a cleaner and more organized code base.
- Introduced developer guides for mobile and web application, allowing a more streamlined development.
Technologies: React, React Native, React Hook Form, Redux, Mobiscroll, Calendars, Expo, TanStack Table, Slack, TypeScript, Mobile, ESLint, Application State Management, Code Review, HTTP REST, User Experience (UX), User Interface (UI), App Store, Typesafe, API Integration, OpenAI, Artificial Intelligence (AI), Expo.io, Tailwind UI, Front-end, React Navigation
Senior Front-end Engineer
2019 - 2024
Netronix
- Developed the mobile application for the AirThinx IoT product—an air quality monitor that allows users to see the air quality they breathe in, all of the essential parameters, and set notifications when the air quality drops.
- Integrated NestJS to further optimize heating and cooling based on alerts fired by the app.
- Delivered a complete redesign and refactor of the app as the sole React Native developer in the team.
Technologies: Agile, Git, Android Studio, Xcode, Enzyme, Appium, Jest, Redux-Saga, Redux, React Native, Visual Studio Code (VS Code), HTML5, React Redux, GitHub, JavaScript, Web Development, CSS, Mobile App Development, Front-end Development, Figma, Teamwork, Complex Application User Interfaces (UI), iOS, Slack, Vanilla JS, Android, TypeScript, Mobile, ESLint, Unit Testing, Application State Management, Code Review, HTTP REST, User Experience (UX), User Interface (UI), App Store, Typesafe, API Integration, GraphQL API, Front-end, Sass, Apollo
Senior Front-end Developer
2021 - 2023
Elligencia
- Developed a widget that can be embedded into any website, using React, allowing for the display of sentiment analysis data provided by the Ellisense API.
- Built the Ellisense website to provide extensive sentiment analysis data for stocks, crypto, and foreign currencies.
- Developed an MVP React Native app for Ellisense, with various chart implementations displaying live data.
- Created a UI system and base components shared by the Ellisense website and widget.
Technologies: React, React Native, Chart.js, SVG Animation, Expo, Tailwind CSS, Next.js, Web Extensions, Visual Studio Code (VS Code), HTML5, React Redux, GitHub, JavaScript, Git, Web Development, CSS, Mobile App Development, Front-end Development, GitLab, Teamwork, Complex Application User Interfaces (UI), Vanilla JS, Bitbucket, Mobile, Application State Management, Code Review, HTTP REST, User Experience (UX), User Interface (UI), Typesafe, API Integration, Artificial Intelligence (AI), Front-end, Sass
Technology Lead
2018 - 2020
Synechron
- Acted as tech lead for a team consisting of 15 people for a React technology.
- Conducted technical interviews and mentored new colleagues.
- Developed the internal web application for a French asset management client.
- Developed common UI tools and libraries used across multiple projects.
Technologies: REST, GraphQL, TestCafe, Storybook, Appium, Enzyme, Jest, Redux, React Native, React, JavaScript, Visual Studio Code (VS Code), HTML5, React Redux, Web Development, CSS, Front-end Development, GitLab, Teamwork, Complex Application User Interfaces (UI), Vanilla JS, Bitbucket, ESLint, Unit Testing, Application State Management, Code Review, HTTP REST, User Experience (UX), API Integration, Artificial Intelligence (AI), Front-end
Front-end Developer
2017 - 2020
Emvisage
- Developed a form builder component with resize, reorder, drag, and drop fields. Forms rendered from JSON structures allowing users to define whatever they want the form to do.
- Built a web platform for business workflow management.
- Created a rule engine for a front-end application to handle various validations.
- Built a custom watcher behavior for input fields.
Technologies: Linter SQL RDBMS, Jest, Storybook, i18n, Cerebral, Git, Redux Thunk, Redux, React, Visual Studio Code (VS Code), HTML5, React Redux, GitHub, JavaScript, Web Development, CSS, Front-end Development, Teamwork, Complex Application User Interfaces (UI), Slack, TypeScript, ESLint, Application State Management, Code Review, HTTP REST, User Experience (UX), User Interface (UI), API Integration, Front-end, Sass
Front-end Developer
2016 - 2020
Freelancer - Contractor Agency
- Developed a number of projects for clients all worldwide.
- Designed a custom React gallery with a pinch, pan, swipe, and zoom behavior fully supported by all browsers.
- Developed various applications working with maps, live, and push notifications.
Technologies: ZenHub, Trello, Jira, Git, JavaScript, HTML, CSS3, CSS, React Native, React, Visual Studio Code (VS Code), HTML5, React Redux, GitHub, Web Development, Mobile App Development, Front-end Development, GitLab, Teamwork, Complex Application User Interfaces (UI), iOS, Bitbucket, Android, TypeScript, Mobile, ESLint, Unit Testing, Application State Management, Code Review, HTTP REST, User Experience (UX), User Interface (UI), App Store, Typesafe, API Integration, Expo.io, GraphQL API, Tailwind UI, Front-end, Material UI, Sass
Full-stack Developer
2016 - 2018
Kolosek
- Developed a React Native application: a social network for business people to appraise each other within the company and between colleagues and ex-colleagues.
- Mentored colleagues transitioning to React technology. Acted as the technology lead for React/React Native projects.
- Assisted in the development of the back end and web application for the same social networking app where I was lead for mobile app development, while handling multiple small- to medium-sized projects.
Technologies: Git, Scrum, Enzyme, Jest, REST, GraphQL, Redux, CSS, HTML, JavaScript, Node.js, React Native, React, HTML5, React Redux, GitHub, Web Development, Mobile App Development, Front-end Development, Teamwork, Complex Application User Interfaces (UI), iOS, Slack, Android, TypeScript, Mobile, Application State Management, HTTP REST, User Experience (UX), User Interface (UI), App Store, Typesafe, API Integration, GraphQL API, Front-end, Material UI
Experience
AirThinx Mobile Application
This React Native multi-platform application allows users to see the air quality reported by AirThinx devices, specify interactions with other integrated IoT devices based on various alerts, and be notified of parameter value changes from a specific profile zone.
CastleKeyp
A React Native hybrid application that is fully end-to-end encrypted, guaranteeing information sharing only between the user and the people they choose. It included the implementation of push notifications, advanced calendar usage, and various form implementations.
Ellisense
Ellisense is an artificial intelligence-powered application that provides up-to-date market sentiment analysis for a variety of assets, including stocks, cryptocurrencies, and foreign currencies. It collects data from various sources and digests them to provide clear market insights with a social sentiment index. It also offers advanced charting to view historical sentiment and spot market mood highlights
Environet
A web-based environmental data monitoring and management platform, allowing real-time data insights, robust analytics, seamless management tools, and the ability to generate accurate, compliance-ready reports in seconds.
Education
2019 - 2021
Master's Degree in Software Engineering
University of Novi Sad - Novi Sad, Serbia
2013 - 2018
Bachelor's Degree in Software Engineering
University of Novi Sad - Novi Sad, Serbia
Skills
Libraries/APIs
React, React Redux, TanStack Table, GraphQL API, Vue, React Navigation, Node.js, Redux-Saga, Chart.js, MobX, Sockets, Highcharts, React Final Form, React Hook Form
Tools
Git, GitHub, Slack, Bitbucket, Expo, GitLab, Expo.io, Jira, Xcode, Android Studio, Redux Thunk, Trello, ZenHub, Figma
Languages
CSS, HTML, JavaScript, TypeScript, HTML5, GraphQL, Sass, CSS3
Frameworks
React Native, Redux, Jest, Vanilla JS, Next.js, Tailwind CSS, Material UI, Appium, TestCafe, Cerebral
Platforms
Typesafe, Mobile, Android, Firebase, MacOS, Visual Studio Code (VS Code), iOS
Paradigms
Unit Testing, Software Testing, Agile, REST, Scrum
Storage
Linter SQL RDBMS
Other
Front-end Development, Teamwork, Application State Management, Code Review, HTTP REST, API Integration, Front-end, Mobile App Development, Web Development, Storybook, Enzyme, Complex Application User Interfaces (UI), ESLint, User Experience (UX), User Interface (UI), App Store, Tailwind UI, Apollo, Software Development, Software Engineering, i18n, Web Extensions, SVG Animation, Social Networks Development, Calendars, App UX, Web UX, VictoryChart, Vite, Mobiscroll, OpenAI, Artificial Intelligence (AI)
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