Research Engineer Intern (Summer 2026)

Cloudflare

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In-Office First seen 1 week, 4 days ago Last seen 8 hours, 9 minutes ago Greenhouse

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Job Description

AI Summary

• Conduct research and engineering projects focused on security, privacy, and scalable computing systems, including work with AI/ML and performance analysis • Collaborate with Cloudflare's research team on open problems in cryptography, network protocols, distributed systems, and Internet infrastructure • Contribute to cutting-edge solutions through software development, data analysis, protocol design, and open source work alongside academic and standards organization partners • Located in Lisbon, Portugal for the summer 2026 internship with a team of experts in applied cryptography, privacy, measurement, and machine learning for systems • Join a company recognized for innovative culture and commitment to building a better, more resilient and transparent Internet

About Us

At Cloudflare, we are on a mission to help build a better Internet. Today the company runs one of the world’s largest networks that powers millions of websites and other Internet properties for customers ranging from individual bloggers to SMBs to Fortune 500 companies. Cloudflare protects and accelerates any Internet application online without adding hardware, installing software, or changing a line of code. Internet properties powered by Cloudflare all have web traffic routed through its intelligent global network, which gets smarter with every request. As a result, they see significant improvement in performance and a decrease in spam and other attacks. Cloudflare was named to Entrepreneur Magazine’s Top Company Cultures list and ranked among the World’s Most Innovative Companies by Fast Company.

We realize people do not fit into neat boxes. We are looking for curious and empathetic individuals who are committed to developing themselves and learning new skills, and we are ready to help you do that. We cannot complete our mission without building a diverse and inclusive team. We hire the best people based on an evaluation of their potential and support them throughout their time at Cloudflare. Come join us!

Available Locations: Lisbon, Portugal

About the department

Cloudflare’s Research Team pursues strategic projects that have a large impact on Cloudflare systems and the Internet at large. Our focus is on solving difficult problems to connect and protect users, applications, and data, while helping to make the Internet more resilient, efficient, and transparent.

In our quest to help make a better Internet, we frequently find ourselves exploring open problems at the boundaries of knowledge in scalable computing, with a focus on security and privacy, using techniques including AI/ML and performance analysis. We make cutting edge research contributions in-house, as well as in collaboration with academia, Internet standards organizations like the IETF, and more!

Our team includes experts in many disciplines, including applied cryptography, privacy, network architectures and protocols, measurement, distributed systems, storage optimization, machine learning for systems, and more. We seek interns that augment our existing expertise as well as those who are working in broadly related areas. We have a vast set of potential projects focussed on our current priorities. We also welcome new ideas via concrete proposals that, more than just satisfying curiosity, may help to improve Cloudflare or aspects of the Internet and surrounding technologies touched by Cloudflare. We are, after all, researchers at heart and love learning, too!

More information about Cloudflare's approach to research can be found here.

What you'll do

Cloudflare's Research Team solves difficult problems in security, privacy, and systems at scale. This involves engineering, data analysis, open source software development, protocol design, implementation of primitives, with lots of measurement alongside.

Successful candidates will be matched to suitable projects in on-going research directions. We also welcome novel proposals and ideas that can help to inform or build a better Internet (in the form of a max 200 word proposal).

The Internet is evolving in ways that challenge convention, and many existing assumptions no longer hold. Interns and internship projects are designed to help maintain the integrity of the Internet, its systems, and its applications. Some of the fundamental areas we’re investigating focus on include advanced cryptography, hardware isolation, balancing user privacy against notions of identity, network and internetwork observability in a seemingly fragmented world, even applications of formal methods at scale — and this is just a small view into our work! We’re also acutely aware that AI will impact all layers of a globally distributed system and the wider Internet.

General Research Intern Requirements

Evidence of tackling hard or open-ended problems
Proven track record of peer-reviewed research, open-source software contributions, or standards development, that is commensurate with level of training --- students at all levels are welcome to apply
Experience clearly communicating research ideas through papers, pre-prints, standards documents, blogs, or similar media
Ability to work in a systems-level programming language (e.g. Rust, C, Go)
Passion for debugging and ensuring system reliability
Familiarity with continuous integration workflows and source control systems (e.g., Gitlab, Github)
Willing and eager to share knowledge, with the skills to do so

Additional Requirements

Knowledge or experience with at least one of the following:

Computer networking protocols (TCP/IP, DNS, BGP, QUIC, etc.) and related algorithms
Machine learning analysis, ideally in systems or network optimization
Authentication protocols, applied cryptography, PKI and SSL/TLS
Operating or distributed systems analysis or development
Measurement for network and computer systems
Proficiency in a scripting language, such as Python

Bonus Points:

Proven track record of independently driving projects in a fast-paced environment
Experience working in groups, or with multiple stakeholders
Able to fluently work across multiple programming languages

Internship Availability and Expectations:

Ability to commit to a 12 week summer internship
In office 3-4 days a week in Lisbon, Portugal

What Makes Cloudflare Special?

We’re not just a highly ambitious, large-scale technology company. We’re a highly ambitious, large-scale technology company with a soul. Fundamental to our mission to help build a better Internet is protecting the free and open Internet.

Project Galileo: Since 2014, we've equipped more than 2,400 journalism and civil society organizations in 111 countries with powerful tools to defend themselves against attacks that would otherwise censor their work, technology already used by Cloudflare’s enterprise customers--at no cost.

Athenian Project: In 2017, we created the Athenian Project to ensure that state and local governments have the highest level of protection and reliability for free, so that their constituents have access to election information and voter registration. Since the project, we've provided services to more than 425 local government election websites in 33 states.

1.1.1.1: We released 1.1.1.1 to help fix the foundation of the Internet by building a faster, more secure and privacy-centric public DNS resolver. This is available publicly for everyone to use - it is the first consumer-focused service Cloudflare has ever released. Here’s the deal - we don’t store client IP addresses never, ever. We will continue to abide by our privacy commitment and ensure that no user data is sold to advertisers or used to target consumers.

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. Please note that any offer of employment may be conditioned on your authorization to receive software or technology controlled under these U.S. export laws without sponsorship for an export license.

Cloudflare is proud to be an equal opportunity employer. We are committed to providing equal employment opportunity for all people and place great value in both diversity and inclusiveness. All qualified applicants will be considered for employment without regard to their, or any other person's, perceived or actual race, color, religion, sex, gender, gender identity, gender expression, sexual orientation, national origin, ancestry, citizenship, age, physical or mental disability, medical condition, family care status, or any other basis protected by law. We are an AA/Veterans/Disabled Employer.

Cloudflare provides reasonable accommodations to qualified individuals with disabilities. Please tell us if you require a reasonable accommodation to apply for a job. Examples of reasonable accommodations include, but are not limited to, changing the application process, providing documents in an alternate format, using a sign language interpreter, or using specialized equipment. If you require a reasonable accommodation to apply for a job, please contact us via e-mail at hr@cloudflare.com or via mail at 101 Townsend St. San Francisco, CA 94107.

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Job Information

Company:
Cloudflare
Location:
In-Office
Experience Level:
Entry
Source:
Greenhouse
Status:
Active

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72 /100

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