Data Scientist Lisboa

Data Scientist

About Cloudflare

Cloudflare is on a mission to help build a better Internet. The company runs one of the world’s largest networks, powering millions of websites and other Internet properties for customers ranging from individual bloggers to Fortune 500 companies. Cloudflare protects and accelerates any Internet application online without adding hardware, installing software, or changing a line of code. The network learns from every request, delivering performance improvements and reducing spam and attacks. Cloudflare has been named to Entrepreneur Magazine’s Top Company Cultures list and ranked among Fast Company’s World’s Most Innovative Companies.

Available Locations

London, Lisbon, New York, Toronto, Remote UK, Remote Germany, Remote US

Role Summary

Our team creates advanced security solutions that help customers filter unwanted Internet traffic. We leverage massive amounts of traffic data and apply advanced machine learning techniques to build models that operate at high volume and velocity with precision, performance, and scalability. Challenges include supporting up to 84 million peak requests per second. Our flagship ML products – Bots
ML, WAF Attack Score, and Page Shield ML – exemplify this work. The team collaborates closely with Product Managers, Software Engineers, and others to ship industry‑leading ML solutions, guided by values of empathy, resiliency, collaboration, and ownership.

Role Responsibilities

We are seeking an experienced Data Scientist with a strong background in Natural Language Processing (NLP) to join our Application Security team. In this role you will:

• Develop and deploy highly scalable machine‑learning models from the ground up.
• Apply advanced NLP techniques to improve security capabilities.
• Collaborate with security experts, engineers, and product teams on cutting‑edge projects.
• Combine data and modeling expertise with security acumen to deliver high‑visibility solutions.

Role Requirements

Must‑Have Skills

• 5+ years of Data Science experience in a large‑scale environment (petabyte scale, globally distributed teams).
• Proficient in Python and R for commercial software development; experience with databases such as Postgres.
• Strong data‑analytical skills with the ability to derive insights and build proof‑of‑concept models.
• Experience working closely with cross‑functional teams (business, engineering, product) to align data initiatives with business objectives.
• Excellent communication and presentation skills for diverse audiences.
• Proven track record of applying data insights and machine learning to address business needs and drive revenue.
• Demonstrated ability to deliver results while maintaining a collaborative work environment.

Nice‑to‑Have Skills

• Experience building low‑latency (sub‑millisecond) ML models in a commercial setting.
• Hands‑on experience with NLP in a production environment.
• Background in machine learning for web security.
• Publication record in top‑tier conferences such as EMNLP or ACL.

What Makes Cloudflare Special?

Project Galileo: Since 2014, Cloudflare has equipped more than 2, 400 journalism and civil‑society organizations in 111 countries with tools to defend against attacks that could censor their work.

Athenian Project: Launched in 2017 to provide high‑level protection for state and local government election websites, serving over 425 local‑government sites in 33 states.

1. 1. 1. 1: A free, privacy‑focused public DNS resolver that does not store client IP addresses, reinforcing a faster, more secure Internet.

Sound like something you’d like to be a part of? We’d love to hear from you!

This position may require access to information protected under U. S. export control laws, including the U. S. Export Administration Regulations. Offers may be conditioned on your authorization to receive software or technology controlled under these laws without sponsorship for an export license.

Equal Opportunity Employment

Cloudflare is proud to be an equal opportunity employer. We are committed to providing equal employment opportunity for all people and place great value on diversity and inclusiveness. All qualified applicants will be considered without regard to race, color, religion, sex, gender identity, sexual orientation, national origin, ancestry, citizenship, age, disability, medical condition, family care status, or any other protected characteristic. We are an AA/Veterans/Disabled Employer.

Cloudflare provides reasonable accommodations to qualified individuals with disabilities. If you require a reasonable accommodation to apply for a job, please contact us via e‑mail at hr@cloudflare.com or mail at 101 Townsend St. , San Francisco, CA 94107.

Seniority level

Mid‑Senior level

Employment type

Full‑time

Job function

Data Science, Machine Learning

Industries

IT Services and IT Consulting, Technology, Information and Internet, Computer and Network Security