Senior Software Engineer - Fintech

Cloudflare; Lisboa; On-site; EUR 90,000 - 120,000; Full time

Job summary

Cloudflare in Lisbon, Portugal is seeking a Senior Software Engineer for the Fintech billing team to design and build reliable financial infrastructure supporting metering, subscriptions, invoicing, payments, and revenue recognition.

You will own projects end-to-end, drive architectural decisions, and ensure accuracy and scalability as Cloudflare grows; focus on Go, REST APIs, and secure microservices in Linux environments.

Qualifications

• Five or more years of professional software engineering experience, or equivalent practical experience.
• Experience building and operating distributed systems or backend services in production.
• Proficiency in Go or another modern programming language, with an interest in working extensively with Go.
• Strong understanding of RESTful APIs, service security, and API standards such as OpenAPI, OAuth, or JWT.
• Working knowledge of SQL, data modeling, and relational databases such as PostgreSQL or MySQL.
• Experience designing secure, highly available microservices in Linux or Unix environments.
• Familiarity with event-driven architectures and asynchronous processing.
• Strong troubleshooting, communication, and project ownership skills.

Responsibilities

• Build Billing Systems: Design, develop, and operate transactional microservices supporting metering, subscriptions, invoicing, payments, and financial workflows.
• Own Projects End to End: Drive initiatives from requirements and technical design through implementation, testing, deployment, and ongoing operation.
• Ensure Accuracy and Reliability: Build fault-tolerant systems that safely handle retries, failures, concurrency, and high transaction volumes while preserving financial correctness.
• Maintain Operational Excellence: Monitor production services, investigate billing issues, improve observability, and address the underlying causes of recurring incidents.
• Shape Technical Direction: Participate in architecture reviews, make pragmatic technical trade-offs, and help improve engineering standards across the billing platform.
• Collaborate Cross-Functionally: Work with Product, Finance, Accounting, Support, and other engineering teams to turn complex business requirements into maintainable solutions.

Skills

Five+ years experience

Distributed systems

Go

REST APIs

SQL

Linux/Unix

Event-driven

Troubleshooting

Tools

PostgreSQL

Redis

Kafka

Kubernetes

Docker

Temporal

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.

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.

About The Role

Cloudflare’s Billing Engineering team builds and operates the systems responsible for usage metering, aggregation, subscriptions, invoicing, payments, and revenue recognition. These systems power billions in revenue and support millions of customers across Cloudflare’s product portfolio.

We are rebuilding key parts of our billing platform to scale with products including AI, Zero Trust, Workers, Bot Management, and DDoS Protection. As a Senior Software Engineer on the Fintech team, you will design reliable financial infrastructure, lead projects from requirements through production, and help ensure billing remains accurate as Cloudflare grows.

Responsibilities

• Build Billing Systems: Design, develop, and operate transactional microservices supporting metering, subscriptions, invoicing, payments, and financial workflows.
• Own Projects End to End: Drive initiatives from requirements and technical design through implementation, testing, deployment, and ongoing operation.
• Ensure Accuracy and Reliability: Build fault-tolerant systems that safely handle retries, failures, concurrency, and high transaction volumes while preserving financial correctness.
• Maintain Operational Excellence: Monitor production services, investigate billing issues, improve observability, and address the underlying causes of recurring incidents.
• Shape Technical Direction: Participate in architecture reviews, make pragmatic technical trade-offs, and help improve engineering standards across the billing platform.
• Collaborate Cross-Functionally: Work with Product, Finance, Accounting, Support, and other engineering teams to turn complex business requirements into maintainable solutions.

Desirable Skills, Knowledge, And Experience

• Five or more years of professional software engineering experience, or equivalent practical experience.
• Experience building and operating distributed systems or backend services in production.
• Proficiency in Go or another modern programming language, with an interest in working extensively with Go.
• Strong understanding of RESTful APIs, service security, and API standards such as OpenAPI, OAuth, or JWT.
• Working knowledge of SQL, data modeling, and relational databases such as PostgreSQL or MySQL.
• Experience designing secure, highly available microservices in Linux or Unix environments.
• Familiarity with event-driven architectures and asynchronous processing.
• Strong troubleshooting, communication, and project ownership skills.

Bonus Points

• Experience with billing, payments, subscriptions, usage metering, invoicing, financial ledgers, or revenue recognition.
• Experience with technologies such as PostgreSQL, Redis, Kafka, Kubernetes, Docker, or Temporal.
• Familiarity with reconciliation, idempotency, auditability, and financial data integrity.
• Experience leading technically complex projects across multiple teams.

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.

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, colour, 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.