Frontend / UI-UX Developer

Onkatec; İzmit; On-site; TRY 270,000 - 380,000; Full time

Job summary

ToptanTR is seeking a Frontend / UI-UX Developer to join the team for a full-time office-based role in Izmit. You will translate designs into efficient, accessible web interfaces for a wholesale marketplace and collaborate with designers and backend developers.

You will build listing, search, cart experiences with a mobile-first approach, measure performance with Lighthouse, and progressively modernize the UI while maintaining a cohesive design system.

Qualifications

• Strong experience in frontend development.
• A portfolio showing live interface work and your design process.
• Design and prototyping experience with Figma or similar tools.
• Experience with responsive and mobile-first design.
• Experience measuring and improving web performance with Lighthouse and Chrome DevTools.
• A strong approach to user experience and usability principles.

Responsibilities

• Prepare user flows, wireframes and prototypes for buyer and seller interfaces.
• Create user-centered interface designs with Figma or similar tools.
• Build product listing, search, filtering, product detail, cart and checkout pages with a mobile-first approach.
• Measure and improve Core Web Vitals, page weight, and image and script loading performance.
• Build a consistent and maintainable component and style library.
• Modernize the existing user interface step by step.
• Evaluate design decisions based on user feedback and data.

Skills

Frontend development

UI/UX design

Figma

Responsive design

Web performance

TypeScript

Tools

Figma

Chrome DevTools

Lighthouse

ASP.NET Core Razor

MVC views

Job description

Employee Type: Full Time – Office
Job Type: Frontend / UI-UX Developer
Industry: E-Commerce / B2B Marketplace

Frontend / UI-UX Developer | ToptanTR

As part of our consulting engagement with ToptanTR, we are looking for a Frontend / UI-UX Developer to join the ToptanTR team.

ToptanTR is a multi-vendor B2B wholesale marketplace where sellers list and manage their products, buyers make wholesale purchases, and order, payment, shipping, commission and invoicing processes are all handled under one roof.

We are looking for a teammate who will make experiences where thousands of products are searched, filtered and added to the cart faster, more accessible and easier to use, and who will build a strong bridge between design and development.

What You’ll Do

• Prepare user flows, wireframes and prototypes for buyer and seller interfaces
• Create user-centered interface designs with Figma or similar tools
• Build product listing, search, filtering, product detail, cart and checkout pages with a mobile-first approach
• Measure and improve Core Web Vitals, page weight, and image and script loading performance
• Build a consistent and maintainable component and style library
• Modernize the existing user interface step by step
• Evaluate design decisions based on user feedback and data

What We’re Looking For

• Strong experience in frontend development
• A portfolio showing live interface work and your design process
• Design and prototyping experience with Figma or similar tools
• Experience with responsive and mobile-first design
• Experience measuring and improving web performance with Lighthouse and Chrome DevTools
• A strong approach to user experience and usability principles

Nice to Have

• Experience working with ASP.NET Core Razor or MVC views
• Experience with e-commerce interfaces and conversion optimization
• Knowledge of building search, filtering, cart and checkout experiences
• Experience building a design system
• Experience with user research and usability testing
• Familiarity with TypeScript, SCSS and modern build tools