Senior Software Engineer - Quicksilver - Distributed Key Value

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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 e join us!

London, Amsterdam, Lisbon, Austin

Quicksilver is Cloudflare’s globally distributed key‑value store. It replicates our data all around the world, over tens of thousands of servers and over 500 data centers. It handles all kinds of network conditions and serves billions of keys per second. In this role, you will own and support the whole stack: the code base, the unit and integration tests, deployment and rollback plans, operations, monitoring, alerting, debugging and on‑call.

Quicksilver is written in Go and

C. If working at this scale excites you and you are intrigued by very tricky bugs, rather than being scared by them, you might be a match for this role.

• Work on our distributed large‑scale key‑value store, write new features in Go and review pull requests
• Improve performance, CPU, memory usage, etc.
• Improve monitoring and tooling, all written in Go
• Help debug and investigate hard‑to‑reproduce problems

• Previous experience writing robust systems with an emphasis on code quality, performance and technical debt
• Proven experience with storage systems, peer‑to‑peer systems, large‑scale distributed systems or system programming
• Ability to chase problems through multiple layers of the software stack, with curiosity and flexibility
• Strong autonomy and independent problem‑solving, with a track record of designing simple yet powerful solutions
• Comfort with both low‑level and high‑level programming and a taste for programming languages
• Active contribution to a team that challenges designs, giving and receiving constructive criticism to produce the best solutions
• Comfortable engaging in outages, possibly during anti‑social hours

We’re not just a highly ambitious, large‑scale technology company. We’re a company that cares deeply about 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.

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. To date, 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 build a faster, more secure, and privacy‑centric public DNS resolver. It is available publicly for everyone to use – we never store client IP addresses and keep a strict privacy commitment.

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. If you require a reasonable accommodation to apply for a job, please contact us at

To join our team, please send your application through our career portal or email your resume to