Middle/Senior React Developer - part time

Permanent employee, Part-time · Remote

Your mission

As a Frontend Engineer at Index, you will primarily focus on building and optimizing high-quality, performant, and SEO-friendly web applications using React and Next.js. You will work closely with product, design, and marketing teams to ensure excellent user experience, strong Core Web Vitals, and reliable analytics and tracking.

This role is ideal for a strong mid-level frontend engineer who takes ownership of UI quality and performance and is motivated to gradually expand into backend development (Ruby on Rails and Python) with mentorship and support.

Key Responsibilities

Frontend Development (React / Next.js)

Build and maintain React and Next.js components, pages, and application logic.
Implement responsive, accessible, and SEO-optimized UI using modern CSS approaches.
Troubleshoot and fix bugs in the existing frontend codebase.
Identify and resolve frontend performance issues (code splitting, memoization, lazy loading).
Monitor and optimize Core Web Vitals in collaboration with product and marketing teams.
Ensure smooth and reliable integration with backend APIs.

SEO, Analytics & Tracking

Implement and maintain technical SEO best practices, including:
- Meta tags and structured metadata
- Schema markup
- Sitemap and robots.txt management
- Core Web Vitals optimization
Implement and manage Google Tag Manager (GTM) setups, including tags, triggers, and variables.
Support analytics and conversion tracking integrations (GA4, Meta Pixel, etc.).
Collaborate with marketing on tracking requirements and data layer implementation.
Debug, QA, and validate analytics and tracking across public-facing pages.

Accessibility & Quality

Apply accessibility best practices for public-facing pages.
Ensure compliance with WCAG accessibility standards.
Write clean, readable, and maintainable frontend code.
Participate in code reviews and contribute to improving frontend standards and patterns.

Backend Exposure & Growth (Nice to Have / Learning Path)

Collaborate with backend engineers to understand API design and data flows.
Gradually contribute to backend tasks using Ruby on Rails and/or Python as part of personal growth.
Learn how frontend decisions impact backend performance and system design.

Tech Stack

Frontend

Next.js, React.js, TypeScript
Tailwind CSS, Shadcn, Radix UI
Framer Motion

Backend (Learning / Exposure)

Ruby on Rails, Ruby, Python

Infrastructure & Tooling

Git, Webpack
PostgreSQL, Redis (exposure)
Docker (basic understanding)

Testing

Jest

Workflow & Communication

Agile methodology
Atlassian Jira, Bitbucket
Slack, Google Meet

Your Profile

Required

Strong knowledge of HTML5, CSS3, JavaScript (ES6+), and TypeScript.
Solid hands-on experience with React.js and modern frontend development.
Experience with Next.js or other SSR/SSG frameworks.
Strong understanding of technical SEO principles and best practices.
Experience with performance optimization and Core Web Vitals.
Familiarity with Tailwind CSS (and/or SASS, Bootstrap).
Experience with unit testing using Jest.
Good understanding of Git and modern build tools (e.g., Webpack).
Ability to work independently with good self-organization skills.

Nice to Have

Desire to learn backend development (Ruby on Rails and/or Python).
Basic understanding of REST APIs and backend concepts.
Knowledge of Feature-Sliced Design (FSD).
Experience with Framer Motion or animation libraries.
Familiarity with Formik and Yup.
Curiosity about system design and platform architecture.

What We Offer

A frontend-focused role with clear ownership and impact.
Close collaboration with product, design, and marketing teams.
Real influence over performance, SEO, and analytics quality.
A supported path toward backend development for those who want it.
A modern tech stack and agile working environment.
A culture that values quality, autonomy, and continuous learning.

Your profile

Strong knowledge in HTML5, CSS3, JavaScript ES6/7, Typescript
ReactJS
SASS, bootstrap, tailwindcss
Unit testing with Jest
Git, Webpack
Independence, good self-organisation, analytical thinking
Beneficial knowledge:
- Feature Sliced Design (FSD) architecture knowledge
- Framer-motion or any animation lib
- Formik & yup
- Rollup.

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About us

Index is a UK-based company providing end-to-end remote-work services, powered by our digital platform. We help leading companies like GoEuro, Vodafone, Venly, YC startups, and 100 more companies to scale their engineering team by finding and managing high-performing tech talent.

The company was founded 2019 and headquartered in London. We unite top engineering talent from around the world and connect them with innovative companies seeking high-performing teams.

It was co-founded by an Oxford alumnus and tech executive with a track record of building successful global teams and scaling output rapidly.

Why Join Index.dev

We are officially recognized by the Financial Times as one of Europe’s fastest-growing companies: in 2024 we ranked 29th overall and 6th in IT & Software among the FT 1000.

We scale faster than market average — enabling us to offer frequent, meaningful opportunities for those who perform.

From Talent Marketplace to Full-Service Software Powerhouse

In October 2025 we completed the acquisition of Codemotion — a seasoned, U.S.-based custom software development company with a 60+ strong engineering team, decades of enterprise-project experience, and clients such as NASA, Neom, and MongoDB.

This strategic move transforms us from a talent-matching platform into a full-fledged software delivery partner: end-to-end solutions, from MVP to production, including CTO-level leadership, project management, design, QA, and scalable engineering teams.

As a result — along with helping hire developers, we’re delivering entire products and complex systems. We now serve clients in 180+ countries, offering broad timezone overlap, flexible staffing models, and a diversity of technical skills and cultural backgrounds.

Our growth trajectory ensures that high-performers don’t just onboard — they accelerate. With access to enterprise-level clients, cross-functional teams, and varied domains (FinTech, Blockchain, Healthcare, AI), talent can grow in ways rarely possible in traditional setups.

Our Vision & Mission: Where We’re Going Next

We are growing fast and have the vision of building the leading software development company in the world.
We believe that remote-first, globally distributed engineering teams are the future.

Our goals include:

1. Expand into a full end-to-end software delivery partner — delivering complete engineering solutions, from CTO-level leadership to full product development.
2. Attract and serve enterprise-level clients — by strengthening delivery quality, project reliability, and compliance to handle complex, high-stakes projects.
3. Deliver speed, quality, and flexibility at scale — ensuring clients get vetted, ready-to-interview talent and high-performing teams with exceptional turnaround time.
4. Sustain rapid, high-quality growth — continuing our momentum as one of Europe’s fastest-growing tech companies while preserving performance, culture, and delivery excellence.

Giving back is part of our DNA. We donate around 10% of the revenue to support vulnerable groups — including children, women, refugees — and invests in education programs for young students and future IT professionals.

If you’re motivated by scale, impact, complex projects, and global collaboration, Index.dev is the kind of place where your efforts will be amplified.
Here are some reviews from our teammates on -> Glassdoor.

You would make an ideal candidate for our company if you are willing to commit to the following:
Above Average Principles:
Integrity.
Respect. Show empathy and respect to others and their feelings; Show others that you care.
Extra-Mile. Excellence and work ethics. Ask the question: “What else can I do?”; Reject average, good to pass by.
Move Quickly and Be Resourcefulness. Do more with less.
Ongoing Learner. Ask the questions: “What coaching do you have for me?” and “What can I do better?“; What is the learning here?.
Team Player. Talent wins games, but teamwork and intelligence win championships.
Extra Smile. We look to the positive side in every situation. We love what we do every day. Ask the question: “What is good in this?”.

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We are looking forward to hearing from you!

Thank you for your interest in Index. Please fill out the following short form. Should you have difficulties with the upload of your data, please send an email to join@index.dev.