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. At Cloudflare, we’re not looking for people who wait for a polished roadmap; we’re looking for the builders who see the cracks in the Internet that everyone else has simply learned to live with. We value candidates who have the instinct to spot a "normalized" problem and the AI-native curiosity to create a solution using the latest tools. Our culture is built on iteration, leveraging AI to ship faster today to make it better tomorrow, while ensuring that every improvement, no matter how small, is shared across the team to lift everyone up. If you’re the type of person who values curiosity over bureaucracy, and that AI is a partner in solving tough problems to keep the Internet moving forward, you’ll fit right in. AVAILABLE LOCATIONS: AUSTIN, TX | SEATTLE, WA | LONDON, UK ABOUT THE ROLE Cloudflare's Developer Platform powers stateful, data-intensive applications across our network. We're looking for a Senior Software Engineer to work across the database stack, from query planning and execution to transaction processing and durable storage. You'll make decisions that shape the consistency, durability, and latency guarantees that customer applications rely on. Correctness under concurrency and failure is central to the role. You'll define and implement how queries read and modify data, how concurrent transactions become visible, and how durable state is recovered. You'll validate these systems using deterministic simulation, workload testing, and evidence from production. RESPONSIBILITIES * Improve query planning and execution, including index selection, row reads and writes, and performance as data volumes and access patterns change. * Build transaction and storage paths that make writes durable and reads consistent. Define when changes become visible, how commits survive failure, and how recovery restores a correct view of the data. * Design deterministic simulations that make rare event orderings and failures reproducible. * Plan stateful upgrades that cannot be reversed by rolling back software. Carry them through staged rollout, failover, and recovery without putting existing data at risk. * Participate in the service's on-call rotation and incident response. * Own major changes from design through production. Coordinate implementation across teams when a change spans multiple parts of the service, and help trace failures across those parts. * Mentor other engineers through design reviews, debugging, and incident analysis involving concurrency, durability, and recovery. DESIRABLE SKILLS, KNOWLEDGE & EXPERIENCE * You have owned a database, storage engine, transaction system, or similarly correctness-sensitive stateful system from architecture through production. You can make architecture and implementation decisions when requirements or system boundaries are incomplete. * You understand how query execution, indexing, transaction processing, and durable state shape what developers and operators observe. * You understand how concurrency control, isolation, replication, and snapshots shape consistency, durability, and recovery. You can apply those concepts when operations arrive out of order, components fail independently, or the network partitions. * You write and debug concurrent production software in Rust, Go, C++, or another systems language. You can trace failures across process, network, and durable-state boundaries. * You have operated stateful systems through rollouts, scaling events, incidents, and recovery. You know the difference between transient unavailability and incomplete or incorrect recovery, and when a system is safe to return to service. * You have led investigations where failures crossed systems owned by several teams. BONUS POINTS * You've worked on the internals of PostgreSQL, MySQL, Amazon Aurora, or another relational database and can trace a SQL operation from planning through commit. * Your work on transaction processing or concurrency control has included defining snapshot visibility and recovery behavior. * You've profiled database workloads and traced performance bottlenecks from query execution through durable storage. * You've used deterministic simulation or another systematic method to uncover distributed-systems bugs that conventional tests missed. 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 hr@cloudflare.com or via mail at 101 Townsend St. San Francisco, CA 94107.