Position: Front-end developer(React native)
Category: JavaScript
English level: upper
Years of experience: 3

Our small team of three people made significant improvements to the performance of our latest project. We achieved a sevenfold increase in app "cold start" speed by optimizing the data-fetching process. Instead of fetching all the data during the initial app loading step, we moved it to later stages where the data is actually required. This reduced the "cold start" time from approximately 40 seconds to just 3-5 seconds.

Additionally, we enhanced performance by relocating heavy calculations related to data serialization from the component's "render" step to the data-fetching hook. This prevented redundant calculations each time the component was opened, resulting in improved efficiency.

Furthermore, we addressed a notable performance bottleneck by fixing incorrect usage of certain data validation libraries. This unexpected issue had a significant impact on the app's overall performance.

Lastly, we optimized component rendering by implementing React best practices, effectively preventing unnecessary re-rendering.

Overall, our team's efforts led to remarkable performance enhancements in the project.
intive
Software Engineer - front-end/cross-platform mobile
01.10.2021 - present
Kyiv, Ukraine

Responsibilities: 
- creation of application user interface and business logic
- implementation of new features(design and behaviour suggested by customer)
- code refactoring(moving from JavaScript to TypeScript, improving the application architecture and structure)
- writing tests(unit, integration, e2e)
- elimination and fixing of program bugs
- code review

Project: Weather Group Television, LLC - Weather Channel Alls
Tech stack and tools: JavaScript, TypeScript, HTML5, CSS, React Native, React Native for Web, Recoil, React Query, Jira/Confluence

Project: intive / intive - UAsos.org 
Tech stack and tools: TypeScript, HTML5, CSS, React Native, React Native for Web, React Query, Jira/Confluence

Project: BlackBerry Limited / BlackBerry Limited - Blackberry - Multi-Tenant Console (MTC) 
Tech stack and tools: JavaScript, HTML5, CSS, React.js, Redux, Redux Saga, Cypress, Jira/Confluence

JavaScript Ninjas
Software Engineer - front-end/cross-platform mobile
01.07.2021 - 01.09.2021
Kyiv, Ukraine

Responsibilities: 
- creation of application user interface and business logic
- implementation of new features(design and behaviour suggested by customer)
- writing tests(unit, integration, e2e)
- elimination and fixing of program bugs
- code review

Project: Snaplaw
Tech stack and tools: JavaScript, TypeScript, HTML5, CSS, React Native, Redax, Redux Saga, Expo, Jira/Confluence

U.Stork Lab
Software Engineer - front-end/cross-platform mobile
01.02.2021 - 01.07.2021
Kyiv, Ukraine

Responsibilities: 
- creation of application user interface and business logic
- implementation of new features(design and behaviour suggested by customer)
- elimination and fixing of program bugs
- code review

Project: Santo Club
Tech stack and tools: JavaScript, CSS, React Native, Styled Components, MobX, Jira/Confluence

Dreambit
Software Engineer - front-end/cross-platform mobile
01.12.2020 - 01.02.2021
Kyiv, Ukaraine

Responsibilities: 
- creation of application user interface and business logic
- implementation of new features(design and behaviour suggested by customer)
- elimination and fixing of program bugs
- code review

Project: E-force
Tech stack and tools: JavaScript, TypeScript, CSS, React Native, Redux, Jira/Confluence

WantToSe
Software Engineer(trainee) - front-end
01.02.2020 -01.08.2020
Phuket, Thailand
Project: wanttosee.world