Jobs JavaScript / Front-End

About the Product

You'll join the team behind an AI size and fit product for fashion brands. Its size advisor combines custom algorithms, product data and shopper preferences to recommend the right size, so retailers sell more and deal with fewer returns. Well-known luxury fashion brands use it on their online stores, and merchants of every size install it through our Shopify app. We're now building virtual try-on as well.

We're a small team spread across the UK, Italy, Germany and Ukraine, so you'll work directly with our CTO, our designer and our product lead.

The Role

We're looking for a strong junior frontend developer who's ready to take a task from ticket to release. Most of your time will go into our Shopify app, which merchants use inside their Shopify admin to set up size charts and configure the size advisor. You'll also work on requests from our brand clients for the size advisor widget that runs on their product pages, and you may help with virtual try-on as it develops.

You'll plan your work in Linear, open pull requests that a teammate reviews, and use AI coding tools every day. We use Claude Code a lot, and we expect you to understand every line it writes for you.

What You'll Do

• Build new features in our Shopify app, such as size chart creation and editing, merchant onboarding, recommendation settings and dashboards.
• Fix bugs and work through the backlog, keeping the app in line with Shopify's Polaris design system and Built for Shopify guidelines.
• Work on our theme app extension and web pixel, the parts of the app that run on merchants' storefronts.
• Deliver customisations, fixes and small features on the size advisor widget for our brand clients.
• Turn Figma designs into responsive, accessible interfaces that work across browsers.
• Write tests for the code you change, using Vitest and Playwright.
• Take part in code reviews, both giving and receiving feedback.

What We're Looking For

• At least a year of commercial experience building React applications, or shipped projects that show the same level.
• Working knowledge of TypeScript.
• Solid JavaScript, HTML and CSS/SCSS, including responsive layouts and cross-browser issues.
• Experience working with REST APIs and handling async data, including loading and error states.
• Basic GraphQL: you can read and write queries (Shopify's Admin API is GraphQL).
• Comfortable with Git, pull requests and code review.
• Good spoken and written English. It's our working language across four countries.
• Hands-on experience with AI coding assistants, and the judgement to check what they produce.
• Working hours that overlap with UK and Central European time. Our daily stand-up is at 9.30am CET (8.30am UK time).

Nice to Have

• Experience building Shopify apps: Remix or React Router 7 (Shopify's current app template), App Bridge, Shopify CLI and theme app extensions.
• Polaris, either Polaris React or the newer Polaris web components.
• Node.js on the server, plus basic Prisma and PostgreSQL.
• Redux Toolkit, Vite and Storybook.
• three.js or React Three Fiber.
• Accessibility (WCAG) and internationalisation (i18n).
• An interest in fashion and e-commerce.

Our Tech Stack

• Shopify app: React, TypeScript, Remix, Polaris, App Bridge, Prisma, PostgreSQL, Vite, pnpm, Biome
• Size advisor widget: React, TypeScript, Redux Toolkit, SCSS, Vite, three.js and React Three Fiber, plus our own component library in Storybook
• Testing: Vitest, Testing Library, Playwright
• Tools: GitHub, Linear, Figma, Claude Code

What We Offer

• Visible work: what you build runs on the online stores of some of the best-known names in fashion.
• Mentoring from our CTO, and a careful review on every pull request.
• A team that releases to production several times a week, so you see your work live within days.

Our Values

• Integrity: We respect ourselves and others, and we do the right thing because it's the right thing to do.
• Own it: We don't pass the buck. The team depends on you and trusts you, and we're collectively accountable for the good outcomes as well as the bad.
• Execution: We want to create something worth creating, so we execute, monitor, learn, adjust and repeat. Iteration is at the heart of everything we do.
• Intellectual rigour: We're passionate about what we do. We encourage rigorous debate and make decisions based on logic, data and facts.
• Collaboration: We value the team over the individual. No one should be afraid to ask for help or unwilling to help others, and that's how we build the highest-quality systems.

Hiring Process

1. A 30-minute introduction call.
2. A technical interview of about an hour with our CTO, including live coding in React and TypeScript.
3. A call with the wider team.
4. Offer.

How to Apply

Apply here on Djinni with your CV and a link to your GitHub profile or something you've built.

We welcome applications from everyone, whatever their background. If you need any adjustments during the hiring process, let us know.

TenThousand is a Ukrainian engineering company that has been developing solutions for Fintech and Retail clients in the US, Israel, and Europe since 2021. Our client base includes banks, fintech companies, and logistics services. We tackle complex technical challenges—such as high-risk projects or those involving legacy architecture—and transform them into reliable, scalable, and stable systems. We work on real commercial projects, applying a product-oriented approach and adhering to high standards of quality and security.

We run our own free 3-month academy and are currently looking to add 5 developers to our team for a remote role.

What you’ll be doing:
• Developing features for real commercial projects for clients in the US, Israel, and Europe
• Working in a team under the guidance of a lead from day one
• Developing your technical skills in an environment that upholds real product standards

Requirements:
• Solid knowledge of React, JavaScript, and TypeScript
• Willingness to learn quickly and adopt new approaches
• Responsibility, initiative, and self-organization
• English proficiency at B1+ level (for working with documentation and basic communication)

What we offer:
• Involvement in real projects from the very first weeks
• Free 3-month internal academy and mentorship
• Systematic professional development and career growth within the company
• Remote work format | Office-based work

Selection stages:
1 HR interview — introduction, motivation, soft skills (20–30 min)
2 Technical assignment or interview with the lead
3 Discussion with the project lead → job offer