Senior Frontend Developer (Part-time; 100% remote)

27 - 39 USDNet per hour - B2B
JavaScript

Senior Frontend Developer (Part-time; 100% remote)

JavaScript
Centrum, Warsaw

DevsData LLC

Part-time
B2B
Senior
Remote
27 - 39 USD
Net per hour - B2B

Job description

Senior Frontend Developer (Part-time; 100% remote)


  • 💰Salary: up to around $40 per hour

  • 💻 100% Remote

  • 🕦 Part-time: Around 10h per week, up to 10-15h/week, as needed

  • ☑️ B2B contract/freelance

  

We are seeking a Senior Front-End Developer to work on the ongoing improvement, maintenance, and optimization of our extensive public-facing website. The role is focused on working with an existing, production-grade codebase built primarily with HTML, CSS, JavaScript, PHP and WordPress, under CloudFlare.


Requirements


  • Expert-level experience in front-end development, with a strong track record of working on long-lived or legacy codebases

  • Website performance optimization experience, web performance tooling and audits (e.g., Lighthouse, Google PageSpeed insights) experience.

  • Ability to work independently (along with a work history of independent work)

  • Excellent knowledge of JavaScript, HTML and CSS, with a clear understanding of responsive design principles

  • Basic understanding of SEO fundamentals, including performance factors, and search-engine-friendly markup

  • Experience working with extensive and legacy frontend systems

  • Strong attention to detail and a quality-focused mindset


Main Responsibilities


  • Optimize page load times and overall website performance using front-end techniques.

  • Working on bugfixes and optimization of a legacy front-end website built with JavaScript, HTML, CSS, and WordPress, ensuring performance, and stability.

  • Improve existing features and user-facing functionality through thoughtful, incremental enhancements rather than full rewrites.

  • Collaborate with internal developers, designers, management, and content teams to implement updates and refinements to existing pages and components.

  • Ensure cross-browser compatibility across the website.

  • Apply front-end SEO best practices, including performance optimization (most importantly), accessibility improvements, page structure, and Core Web Vitals.


Get to know DevsData:


We are a technology consulting company and a recruitment agency, delivering software solutions to clients from Europe and the US. We work 100% remotely, in an international team, including people from Asia, London, or San Francisco. We employ people with experience in international corporations as well as students of the best technical and business universities. Find out more: https://devsdata.com/


Tech stack

    JavaScript

    advanced

    HTML

    advanced

    CSS

    advanced

Office location

Published: 19.01.2026

About the company

DevsData LLC

DevsData is a premium recruitment and software development agency specialized in developing unique software, artificial intelligence, and Big Data solutions. We’re working 100% remotely so that we can change the world fr...

Company profile

Senior Frontend Developer (Part-time; 100% remote)

27 - 39 USDNet per hour - B2B
Summary of the offer

Senior Frontend Developer (Part-time; 100% remote)

Centrum, Warsaw
DevsData LLC
27 - 39 USDNet per hour - B2B
By applying, I consent to the processing of my personal data for the purpose of conducting the recruitment process. Informujemy, że administratorem danych jest DevsData LLC z siedzibą na 1820 Avenue M #481, Brooklyn, NY 11230, USA (dalej jako "admini... MoreThis site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.