Web Performance Engineer

DNA.inc; Madrid; A distancia; EUR 60.000 - 80.000; A tiempo parcial

Descripción de la vacante

A technology consulting firm based in Madrid is seeking an experienced Web Performance Engineer for a 6-month freelance role. You will audit and optimize web performance across multiple sites, enhance loading times, and collaborate with engineering teams. The ideal candidate should have specialization in site performance, a track record of improving high-traffic sites, and experience with caching strategies. This position offers a chance to work on impactful products in a remote-enabled environment.

Servicios

Mentorship and learning budgets

Participation in conferences

Clear long-term career path

Formación

• Specialization in site performance and Core Web Vitals.
• Deep understanding of web loading, rendering, and CDN optimization.
• Proven track record improving loading times for high-traffic websites.

Responsabilidades

• Audit and analyze current site performance to identify bottlenecks.
• Optimize Core Web Vitals to meet target metrics.
• Implement caching strategies to reduce load times.

Conocimientos

Site performance

Core Web Vitals

API decoupling

Caching strategies

Collaboration with stakeholders

Descripción del empleo

You’re the wizard, the alchemist others turn to when next-level results are required.

DNA.inc is looking for an experienced Web Performance Engineer with a laser-like focus, who can deliver significant improvements in page performance across our client’s main website, their customer support website, key landing pages, and sales flows. By bringing load times on these properties in line with target metrics, you will be instrumental in helping our client improve marketing ROI, sales flow effectiveness, and overall customer acquisition.

About the job

In this 6 month freelance assignment, we will lean on your expertise and deep experience with large, corporate web structures to help our client achieve its goals.

Where your contributions are concerned, we’ll particularly look to you to:

• Audit and analyze current site performance across multiple properties, identifying bottlenecks and opportunities for improvement.
• Optimize Core Web Vitals (LCP, FCP, CLS, FID) to ensure the client meets and exceeds target metrics.
• Implement advanced caching strategies, including CDN configuration and edge caching, to reduce load times.
• Decouple APIs and optimize data fetching for dynamic content to improve responsiveness and user experience.
• Enhance rendering performance through image optimization, code‑splitting, lazy loading, and critical CSS strategies.
• Work with multiple stakeholders, including product, marketing, and engineering teams, to align performance goals with business objectives.
• Benchmark and track improvements over time using real user monitoring (RUM) and synthetic testing tools.
• Mentor and advise other engineers on performance best practices and scalable architecture strategies.

About you

To be considered a candidate for this position, we expect you to have:

• Specialization in site performance and Core Web Vitals
• Deep understanding of web loading, rendering, browser behavior, architecture, networking, and CDN optimization
• Skilled in caching strategies, API decoupling, and static vs. dynamic content tradeoffs
• Proven track record improving loading times for high‑traffic, consumer‑facing websites
• Comfortable working in a complex ecosystem with multiple landing pages, experiments, and third‑party integrations
• Seniority to communicate progress, tradeoffs, and decisions with executives and cross‑functional stakeholders
• Able to collaborate effectively with U.S.-based teams in a corporate environment

Who we are

At DNA.inc, we love building platforms and products that people want to use. We help clients envision, build, and launch large‑scale software projects in streaming, media, automotive, and other industries. Headquartered in Europe with hubs in Amsterdam, Valencia, and Madrid, we combine a remote‑enabled business model with a passion for working on influential products that reach global audiences.

You’ll collaborate with experienced designers, engineers, and executives who have contributed to major streaming services such as Disney+, ESPN+, Eurosport, and SiriusXM. At the same time, you’ll grow within a culture that celebrates expertise and supports your development through mentorship, learning budgets, conference participation, and a clear long‑term career path.

Interested?

Ready to join us? Apply directly through our website — we’d love to hear from you!

Please note that, to safeguard the quality and integrity of our services, all hires complete a standard screening process including reference, education, credit, and background checks.

For any questions or further information, reach out to [e-mail]. Please, no recruiters.