Senior Software Engineer - Quicksilver - Distributed Key Value

Cloudflare; Amsterdam; On-site; EUR 120,000 - 180,000; Full time

Benefits offered by this job

Medical/Rx Insurance

Dental Insurance

Vision Insurance

Flexible Spending Accounts

Commuter Spending Accounts

401(k) Retirement Savings Plan

Employee Stock Participation Plan

Job summary

Cloudflare seeks a seasoned systems engineer for the Quicksilver team in Amsterdam. You will own and evolve a globally distributed key-value store written in Go and C, addressing tough reliability and performance challenges at edge scale.

You’ll work across the stack from code and tests to deployment, monitoring, and on-call incident response, collaborating with engineers worldwide to ship robust, low-latency systems that withstand chaotic conditions.

Qualifications

• Experience building robust systems with attention to code quality and performance.
• Proven experience with storage or distributed systems or system programming.
• Ability to trace problems across multiple software layers and propose simple, effective designs.
• Autonomy and ability to think out of the box in complex issues.

Responsibilities

• Write new features in Go and review pull requests for the distributed store.
• Improve performance, CPU, memory usage, and overall efficiency.
• Enhance monitoring and tooling written in Go, facilitating operations.
• Debug and investigate hard-to-reproduce problems and contribute to on-call support.

Skills

Go

C

Distributed systems

Kernel debugging

Performance optimization

On-call experience

Education

Bachelor's degree in Computer Science

BSc in a related field

Tools

Linux

Go tooling

Git

Job description

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.

Available Locations

• Atlanta, US
• Austin, US
• Denver, US
• New York, US
• Seattle, US
• Washington DC, US
• Amsterdam, Netherlands
• London, UK

Applications will be accepted until November 19, 2026.

About The Role

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 can expect to see challenges like unexpected network issues, hardware failures, kernel bugs and still have to deliver the data to the edge in a fast and reliable way. Along with the rest of the team, you will own and support the whole stack: the code base, the unit and integration test, 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.

This role may require flexibility to be on-call outside of standard working hours to address technical issues as needed.

What You’ll Do

• Work on our distributed large scale key-value store, you will write new features in Go and reviewing pull request
• Improve performance, CPU, memory usage, etc.
• Improve our monitoring and our tools, all written in Go
• Help with debugging and investigating hard to reproduce problems

Desirable Skills, Knowledge, and Experience

• You have previous experience writing robust systems, code quality, performance and technical debt. You understand the tradeoffs that doing rigorous engineering requires.
• You have proven experience with storage systems, peer to peer systems, large scale distributed systems or simply system programming in general.
• You have previous experience of chasing problems through multiple layers of our software stack. You can be flexible and you are very curious.
• You are flexible and very autonomous. You won’t be micromanaged in this role and will be looked to have experience thinking out of the box and coming up with simple and smart designs for complex issues.
• You have a previous track record of being pragmatic and believe in the value of simple solutions.
• You equally enjoy low-level and high-level programming. You have a taste for programming languages.
• You enjoy being a part of a team that challenges each other's designs -- you are good at taking and giving constructive criticism with a goal of producing the best solution.
• You are not afraid of engaging in outages on anti-social hours.

Compensation

Compensation may be adjusted depending on work location.

• For Colorado based hires: Estimated annual salary of $168,000 - $231,000
• For Washington based hires: Estimated annual salary of $185,000 - $254,000
• For Washington DC based hires: Estimated annual salary of $185,000 - $254,000

This role is eligible to participate in Cloudflare's equity plan.

Benefits

Cloudflare offers a complete package of benefits and programs to support you and your family. Our benefits programs can help you pay health care expenses, support caregiving, build capital for the future and make life a little easier and fun! The below is a description of our benefits for employees in the United States, and benefits may vary for employees based outside the U.S.

Health & Welfare Benefits

• Medical/Rx Insurance
• Dental Insurance
• Vision Insurance
• Flexible Spending Accounts
• Commuter Spending Accounts
• Fertility & Family Forming Benefits
• On-demand mental health support and Employee Assistance Program
• Global Travel Medical Insurance

Financial Benefits

• Short and Long Term Disability Insurance
• Life & Accident Insurance
• 401(k) Retirement Savings Plan
• Employee Stock Participation Plan

Time Off

• Flexible paid time off covering vacation and sick leave
• Leave programs, including parental, pregnancy health, medical, and bereavement leave

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!

Please note that applicants who progress to the offer stage of the interview process may be asked to attend an in-person interview within one of the Cloudflare Offices or Cloudflare Hubs. More details about this will be available at that stage of the interview process.

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 [e-mail] or via mail at 101 Townsend St. San Francisco, CA 94107.