Software Engineer - Client Services (CSS, Vanilla JS)

We are looking for a Senior Software Engineer who is comfortable working with Vanilla JavaScript, HTML, and CSS to build and customize frontend solutions, debug complex client-side issues using browser developer tools, and handle DOM manipulation, event handling, and dynamic UI updates. Should be confident analyzing APIs through Fetch/XHR requests, tracking DOM changes using MutationObserver and browser console techniques, and making real-time UI modifications using inspect element and custom scripts. The role also requires troubleshooting frontend issues across browsers and collaborating with cross-functional teams to solve real-world client scenarios while ensuring smooth and optimized user experiences.

Key Responsibilities:

Examples of Tasks You Will Perform

• Rearranging elements on a page dynamically.
• Creating new UI blocks using JavaScript, jQuery and CSS.
• Overriding existing styles safely.
• Preventing interference from existing scripts and styles.
• Ensuring compatibility across devices and screen sizes.
• Making changes that survive dynamic DOM updates.
• Tracking user interactions for experiments.

Key Skills Required

• Strong understanding of Vanilla JavaScript, jQuery, HTML and CSS.
• Advanced DOM traversal and manipulation.
• Event handling and debugging in live environments.
• Using MutationObservers for dynamic content.
• Handling Single Page Applications (SPAs).
• Writing safe and conflict-free CSS.
• Understanding browser behaviour and edge cases.
• Performance-safe scripting on production websites.

Important Mindset Difference

This role is highly problem-solving oriented. There is no clean HTML, no reusable components. You must analyse the DOM like a detective and figure out how to safely manipulate it in real-time.

Who Will Enjoy This Role

• Developers who love JavaScript, jQuery and CSS deeply.
• Those who enjoy solving DOM challenges.
• People are comfortable working without access to source code.
• Developers who like debugging tricky real-world issues.

We don’t build websites — we intelligently manipulate the DOM using Vanilla JavaScript, jQuery and CSS to run experiments on live websites.

Wingify is a remote-first company with more than $100M in revenue, serving over 4,000 customers worldwide, supported by a team of nearly 800 talented people across 11 global offices.

At Wingify, we are committed to fostering an inclusive and diverse workplace. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, sexual orientation, gender identity, national origin, disability, or any other characteristic protected by applicable laws.

Learn more: https://wingify.com/careers/equal-opportunity-policy/