Senior Software Engineer (Distributed Databases)

Cloudflare, Inc.; United Kingdom; On-site; GBP 120,000 - 170,000; Full time

Benefits offered by this job

Stock ownership

Paid parental leave

Healthcare coverage

Pension plan

Commuter benefits

Job summary

Cloudflare, Inc. is seeking a Senior Software Engineer to work across the database stack—from query planning to durable storage. You will shape consistency, durability, and latency guarantees for customer applications and own major changes from design through production.

You will mentor engineers, participate in on-call rotations, and guide upgrades that ensure zero data loss during rollout. Strong experience with PostgreSQL/MySQL internals and systems languages is required.

Qualifications

• Extensive experience with large-scale database systems.
• Strong knowledge of concurrency, durability, and recovery.
• Proficient in at least one systems language: Rust, Go, or C++.
• Experience with production-grade deployments and on-call.

Responsibilities

• Own major changes from design through production.
• Coordinate cross-team implementation and trace failures.
• Mentor engineers in design reviews and incident analysis.
• Participate in on-call rotations and incident response.
• Plan stateful upgrades with safe rollout and recovery.

Skills

Systems programming

Concurrency control

Rust/Go/C++

Database internals

Deterministic simulation

Tools

PostgreSQL internals

MySQL internals

Aurora internals

Job description

• 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
• 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

Benefits

• Competitive pay: We offer a competitive total rewards package, where every employee is an owner of our stock.
• Take-what-you-need vacation: We encourage employees to find a comfortable work-life balance by taking as many days off as they need while still being able to perform their jobs satisfactorily. (We really mean it!)
• Paid maternity & paternity leave: Our global parental leave policy allows up to sixteen paid weeks of bonding leave time for all qualifying new parents.
• Employee benefits: We offer a comprehensive benefits package including healthcare, life insurance, short- and long-term disability, pension plans in accordance with the market practice in our locations.
• Commuter program: We are flexible about where we work and value connecting at the office. Our commuter benefits program is in place to support team members’ commute to work via public transportation without the extra cost burden.
• Wellbeing: Global offerings that provide mental health, childcare and family forming support to our employees across our offices.

You have owned a database, storage engine, transaction system from architecture through production. You can make architecture and implementation decisions when requirements or system boundaries are incompleteYou 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 partitionsYou understand how query execution, indexing, transaction processing, and durable state shape what developers and operators observeYou 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 serviceYou have led investigations where failures crossed systems owned by several teamsYou write and debug concurrent production software in Rust, Go, C++, or another systems language. You can trace failures across process, network, and durable-state boundariesYou’ve worked on the internals of PostgreSQL, MySQL, Amazon Aurora, or another relational database and can trace a SQL operation from planning through commitYour work on transaction processing or concurrency control has included defining snapshot visibility and recovery behaviorYou’ve profiled database workloads and traced performance bottlenecks from query execution through durable storageYou’ve used deterministic simulation or another systematic method to uncover distributed-systems bugs that conventional tests missed