Frontend Engineer

Sandeep Nijjar.

Building performant, accessible solutions with clean, maintainable code for over 10 years.

Get in touch

Skills & Stack

    • HTML5
    • CSS3
    • JavaScript (ES2024)
    • TypeScript
    • React
    • Next.js
    • Global state management
    • Tailwind CSS
    • Webpack
    • Vite
    • Git
    • Claude
    • Node.js
    • REST
    • CI/CD
    • PostgreSQL

Featured Projects

  • Marketing site · 2023

    Devoted k9 Training

    A marketing site for a London-based dog training business offering 1-2-1 sessions, residential programmes, and group classes. Built to convert visitors through clear service pages, client testimonials, and a streamlined booking flow.

    Devoted k9 Training screenshot
    • Next.js
    • TypeScript
    • Styled Components
    View →
  • Marketing site · 2024

    Saintk9 Training

    A marketing and booking site for a dog training business, with Calendly embedded for session scheduling and integrated payments — letting clients book and pay without leaving the site.

    Saintk9 Training screenshot
    • Next.js
    • Tailwind CSS
    • Calendly
    View →

Work Experience

  1. Permanent

    Senior Software Engineer

    dunnhumby

    Led the main product UI overhaul (35+ enhancements, 5,000+ weekly users), migrating the platform fully to React — reducing bounce rate on ordering pages by 10%, making report ordering 37% faster, and lifting user satisfaction by +9.3pp. Directed a frontend architecture overhaul, defined coding standards, and designed a scalable onboarding path that helped 8 cohorts contribute to production work quickly.

    • React
    • TypeScript
    • Zustand
    • React Query
    • Cypress
  2. Contract

    Senior Frontend Developer

    BCG

    Delivered the MVP on time for 5 prominent dental practices, owning technology selection and configuring the full frontend stack from scratch. Selected Tailwind CSS for a mobile-first approach given the majority of users accessed via mobile. Collaborated with backend engineers to define the API contract.

    • React
    • TypeScript
    • Tailwind CSS
    • Zustand
    • React Query
  3. Contract

    Senior Frontend Developer

    Instinct Digital

    Overhauled the design system to ensure consistent components across all products, reducing duplicated components by 40%. Led UI development and bug-fix effort ahead of a major release for Allianz Bank, delivering a seamless launch with zero critical issues.

    • React
    • TypeScript
    • Redux
    • Styled Components
  4. Contract

    Senior Frontend Developer

    Starrez

    Wrote comprehensive Cypress end-to-end tests across all target environments. Improved accessibility and usability using AXE dev tools and keyboard-guided tests. Engaged directly with platform users at a conference to gather qualitative feedback informing roadmap decisions.

    • React
    • TypeScript
    • Next.js
    • Cypress
    • Styled Components
  5. Contract

    Lead Frontend Developer

    Creative Boomerang

    Migrated an e-commerce site from Subbly to Shopify using a custom-built theme, increasing long-term subscriptions by 75%. Built a Next.js static site with server-side rendering that boosted organic search query volume by 25%.

    • Next.js
    • Shopify
    • Liquid
    • TypeScript
    • Styled Components
  6. Permanent

    Senior Frontend Developer

    Integrate

    Led the frontend design system project, producing uniform reusable components and eliminating 80% of redundant CSS previously imported from Material UI and AntDesign. Participated in cross-team code reviews with the US engineering team and mentored junior developers across hiring, onboarding, and pair programming.

    • React
    • TypeScript
    • Redux
    • Storybook
    • Styled Components
  7. Contract

    Senior Frontend Developer

    Elective Technology

    • React
    • TypeScript
    • Styled Components
    • Material UI
  8. Permanent

    Frontend Developer

    Semantic Integration

    • React
    • TypeScript
    • Redux
    • SASS
    • TDD
  9. Permanent

    Frontend Developer

    Newsquest

    • HTML5
    • JavaScript
    • SASS
    • Optimizely
  10. Permanent

    Frontend Developer

    BuyAGift

    • HTML5
    • SASS
    • JavaScript
  11. Permanent

    Frontend Developer

    Dixons Retail

    • HTML5
    • SASS
    • JavaScript