Berk Elmas, Developer in Istanbul, Turkey
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Berk Elmas

Verified Expert  in Engineering

Software Developer

Istanbul, Turkey
Toptal Member Since
September 15, 2020

Berk is a JavaScript/TypeScript developer who utilizes modern web and hybrid mobile application frameworks (React, React Native, Ionic, Angular, and Stencil.js). Besides his JavaScript/TypeScript expertise, Berks is also known for his deft hand with SCSS, Less, and Sass as CSS preprocessors while always taking into consideration current CSS design patterns to obtain clean and readable CSS code.


Fortune 500 Enterprise
JavaScript, React, Next.js, D3.js, GraphQL, React Apollo, Apollo, TypeScript...
Redux Thunk, Redux, React Native, JavaScript, TypeScript, CSS, HTML, REST APIs...
Digitarc Software LLC
Three.js, D3.js, Formik, Redux, React Native, Angular, React, JavaScript...




Preferred Environment

CSS, Less, SCSS, D3.js, Algorithms, Ionic, Stencil.js, Angular, React Native, React, JavaScript

The most amazing...

...thing I've developed is CarValoo's fleet management app which received the Red Dot Design Award.

Work Experience

Senior React Front-end Engineer

2020 - PRESENT
Fortune 500 Enterprise
  • Led the whole legacy system migration to GraphQL by using React Apollo.
  • Migrated all frontend apps from a monolithic architecture to monorepo by utilizing Nx.
  • Led one of the biggest beverage brands' WordPress to React (Next.js) migration by converting the whole system using headless CMS.
Technologies: JavaScript, React, Next.js, D3.js, GraphQL, React Apollo, Apollo, TypeScript, CSS, HTML, REST APIs, API Integration

Remote React Native Developer

2020 - 2020
  • Contributed to the development of Justmop's cleaning service hybrid mobile application.
  • Refactored the form state management parts of the application.
  • Followed the Agile methodology by obeying all of the flow while utilizing Jira.
  • Utilized Redux store management in the application as the global store with Redux Thunk.
  • Participated in constructing the deep linking architecture and then migrating the deep linking into universal deep linking throughout the application.
Technologies: Redux Thunk, Redux, React Native, JavaScript, TypeScript, CSS, HTML, REST APIs, API Integration

Senior Front-end Developer

2019 - 2020
Digitarc Software LLC
  • Served as the lead front-end developer and built the CarValoo fleet management system, which won the Red Dot Design Award.
  • Utilized the Agile methodology and stuck to a completely Agile flow.
  • Used D3.js to build custom data visualizations; these indicated which car parts received damage and what type during specific time periods.
  • Developed, for those data visualizations, custom SVG vehicle models with event indicators; also connected these event indicators to custom SVG timeline charts to show when those events occurred.
  • Open-sourced some project modules and received contribution requests from a few JavaScript groups.
  • Used Redux for state management with Redux Thunk to handle async events in Redux Action Creators.
  • Displayed the vehicle model as a 3D demo along with its events on it (Three.js). However, it has not been officially implemented in the project.
Technologies: Three.js, D3.js, Formik, Redux, React Native, Angular, React, JavaScript, TypeScript, Amazon Web Services (AWS), CSS, HTML, REST APIs, API Integration

Remote Front-end Developer

2017 - 2019
BKB Software LLC
  • Developed an ERP system that handles the management of human resources, internal notifications, reporting of employees, and tracking income from medical imaging devices (e.g., MRIs, CTs) from a single app with multi-tenancy architecture.
  • Utilized React Native on the mobile application and Angular on the web application.
  • Utilized Redux for state management in React Native and NgRx with effects as state management in the Angular app.
  • Published the mobile application as an enterprise app on iOS and solved many problems with publishing as an enterprise application.
  • Developed a digital signature system for taking digital signatures for patients' consent on medical imaging scans such as MRIs or CTs.
  • Utilized Pixi.js with WebGL to obtain patient signatures on tablet devices.
Technologies: PixiJS, Angular, React Navigation, React Native, Formik, Redux, React, JavaScript, TypeScript, CSS, HTML, REST APIs, API Integration

CarValoo Fleet Management

The project involved tracking cars from the connected IoT devices which notifies the user about any kind of damage. The incoming data is served to the web client, which provides engineers with the latest data about any car.

The project required a lot of complex data visualization; therefore, I've utilized D3.js for SVG animations and data chart construction. I have even open-sourced a chart developed during the project, which required zooming in-out on a yearly time scale to daily time scale, connecting its state with third-party React components and clustering data just like in maps.

I also coded a clustering algorithm for the data. For instance, if the data groups get too close to each other, I needed to prevent their intersections, so a custom clustering logic is implemented by me. Via this clustering logic on the client side, the back end sends all the data to front end; and the front end handles all the clustering and data visualization logic by itself.

In the project, tracking of IoT sensor data is made easy with custom interactive D3.js charts (built with SVG). Besides the charts, the car is also coded with SVG, and the part of the vehicle, which sends the sensor data can be viewed easily with this SVG visualization.

E-Work ERP

The project involved the management of human resources, internal notifications, reporting of employees, and tracking income derived from medical imaging devices (MRIs, CTs, and so on) from a single application with multi-tenancy architecture.

The team included five people, a business analyst, two back-end developers, a test engineer, and a front-end developer. As the sole front-end developer, I developed all the interfaces with React Native and Angular. I also served as a front-end architect by constructing all the state management and making the final calls on all the design patterns and UI kits for all front ends.

I used Redux on React Native and NgRx on Angular to store user roles and give specific users access to certain routes or components. I also wrote custom directives in Angular to render components and issue some parameters to routes to decide if routes are accessible or not. Concerning the React Native portion, I coded some higher-order components utilizing the Redux state to decide whether the component should be rendered for the user. In both apps, the global store saved all the role information for users.

Smolt Order Delivery Application
Smolt is an order management app for small-to-middle-sized businesses in the United Kingdom. A user can easily plan the delivery schedule with the drag-and-drop feature. Financial reports of the process are reported via charts, a filter option that allows one to obtain specific snapshots, and communication access is given to the entire team through the app.

Smolt is an Angular project which has monorepo architecture via Nx. NgRx is utilized for state management. Thanks to the project consisting of multiple depth levels of projects and modules, state management architecture with NgRx was constructed with various levels of state instances.

On the UI/UX side, Ng-bootstrap was used for input elements, cards, and so on.

Digital Signature System

The project was about obtaining a digital signature for a patient's consent to undergo a medical imaging scan. The app consisted of a large form that answered pertinent questions about the patient's status related to medical imaging, such as "Does she/he have a metal implant on his/her body?" "Does he/she have claustrophobia?" and so on. After reviewing all these related questions, the patient states his/her consent via a digital signature on a tablet device (iOS/Android).

The hard part was handling this form with a stepper form logic in the front end, a signature in a PNG file format, and sending all this data to the back end after the form is completed.

Besides the stepper, the form also required different questions depending on the medical imaging device because an MRI device requires different questions than a CTI device. Therefore, I have set up Redux as a global store and Axios for HTTP requests to the back end. Users could sign in with the same authentication credentials as they do in E-Work, and they would complete the form depending on the data attached to the patient's status. After completing the form, the patient can sign with their finger or tablet pen.
2015 - 2019

Bachelor's Degree in Law (Legal Practice)

Istanbul University - Istanbul, Turkey

2015 - 2019

Bachelor's Degree in Economics and IT Management

Istanbul University - Istanbul, Turkey


React LinkedIn Assessment



Angular LinkedIn Assessment



JavaScript LinkedIn Assessment



React, REST APIs, D3.js, Node.js, Formik, Three.js, React Navigation


Stencil.js, Redux Thunk, React Apollo


React Native, Angular, Redux, Next.js, Angular 5, Angular 6, Ionic, PixiJS


JavaScript, HTML, CSS, TypeScript, SCSS, Less, GraphQL


Agile Software Development, Scrum, Test-driven Development (TDD)


Amazon Web Services (AWS)


API Integration, Algorithms, Internet of Things (IoT), Fleet Management, Clustering Algorithms, SVG, Data Visualization, Front-end Development, Monorepos, Axios, Digital Signatures, Law, Apollo

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