Sr. Software Engineer (Python, C#)

Proofpoint; Belfast City District; On-site; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Competitive compensation

Comprehensive benefits

Flexible work environment

Annual wellness days

Job summary

Proofpoint is seeking a Senior Software Engineer to join the XFI team within the Cloud Integration Group. You’ll help integrate threat defence software with major email platforms, scale services, and advance with Microsoft and Google integrations. You’ll work in a fast-paced, security‑conscious environment, delivering reliable, scalable systems.

Join a team that values DevOps culture, data‑driven decisions, and cross‑functional collaboration to defend data and protect people at scale.

Qualifications

• Provide or help providing solution to complex problems.
• Design and build reliable distributed systems that handle volumes of data with low latency.
• Maintain and support business‑critical systems where scale and latency are front‑of‑mind.
• Ship code to production every day using CI/CD.
• Tackle the challenges that come with processing sensitive data.
• Learn to build with security in mind.
• Make your mark on ambitious projects.

Responsibilities

• Provide or help providing solution to complex problems
• Design and build reliable distributed systems that handle volumes of data with low latency
• Maintain and support business‑critical systems where scale and latency are front‑of‑mind
• Ship code to production every day using CI/CD
• Tackle the challenges that come with processing sensitive data
• Learn to build with security in mind
• Make your mark on ambitious projects

Skills

Python 3.10

Object‑Oriented

C#

AWS

NoSQL/SQL

Terraform

CI/CD

Docker

Git/GitHub

Tools

Terraform

Docker

Git

GitHub

CircleCI

Job description

About Us

Proofpoint is a global leader in human- and agent-centric cybersecurity. We protect how people, data, and AI agents connect across email, cloud, and collaboration tools. Over 80 of the Fortune 100, 10,000 large enterprises, and millions of smaller organizations trust Proofpoint to stop threats, prevent data loss, and build resilience across their people and AI workflows. Our mission is simple: safeguard the digital world and empower people to work securely and confidently. Join us in our pursuit to defend data and protect people.

Half a million customers, including 87 of the Fortune 100, rely on Proofpoint to protect their organizations.

How We Work

At Proofpoint you’ll be part of a global team that breaks barriers to redefine cybersecurity guided by our BRAVE core values: Bold in how we dream and innovate Responsive to feedback, challenges and opportunities Accountable for results and best in class outcomes Visionary in future focused problem-solving Exceptional in execution and impact.

The Role

We are looking for a Senior Software Engineer to join the XFI (Cross Functional Integrations) team within the Cloud Integration Group. The XFI team oversees the integration of Post Delivery Protection & Response threat defence software, via API, to the Microsoft or Google e‑mail platforms, for both inbound and outbound. You will be joining the team at an exciting time, as the team prepares to furtherly scale the XFI services and products and the next steps of integration with Microsoft and in future with other email providers.

Responsibilities

The XFI Team, we deeply appreciate DevOps culture, as we build the XFI services, and we run it. Our day to day involves improving XFI services scalability and reliability; researching security vulnerabilities and implementing security measures; and monitoring production environments to discover what is next for the team using product data. Our research also includes ways to improve user experience when using our products Outlook clients (desktop and OWA) on both Windows and Mac platforms and to help hardening the Human Security Layer.

• Provide or help providing solution to complex problems
• Design and build reliable distributed systems that handle volumes of data with low latency
• Maintain and support business‑critical systems where scale and latency are front‑of‑mind
• Ship code to production every day using CI/CD
• Tackle the challenges that come with processing sensitive data
• Learn to build with security in mind
• Make your mark on ambitious projects

What You Bring to the Team

The XFI team’s tech stack includes:

• Python 3.10 or
• Other Object‑Oriented Programming languages are a bonus
• C# is applicable to one of our key services
• AWS Services such as SQS, SNS ECS, ECR, Lambda functions
• High volume NoSQL and SQL databases such as Dynamo DB, Postgres
• Terraform built environments
• DevOps tools and methodologies such as: CircleCI pipelines management, Docker containerization, Git and GitHub for software versioning
• Operating on product integration with the main e‑mail platform providers such Google and Microsoft, is an interesting challenge with significant technical complexity, especially when considering the scale of our traffic and our security guarantees.

Our standards around security, quality, and service availability can only be the highest, but at the same time we foster psychological safety, as we are comfortable with the unknowns and love to experiment to find the right solution, which get things done and keep the eyes on results. We use data to validate our decisions, measuring our progress and success. Data informs our decision making, our goals, and our roadmap. We are sure you will love joining us if you share our focus on outcomes rather than outputs and leverage factual evidence to justify your arguments and influence the direction of the team. Our main challenge ahead is scaling, both vertically (size of individual tenants) and horizontally (number of total tenants). We will consider experience working with data and infrastructure at scale as a bonus. If you are not sure that you exactly fit all the above criteria, please do get in touch anyway. We are always willing to speak to great candidates even if you do not feel you meet every criteria listed!

Why Proofpoint?

At Proofpoint, we believe that an exceptional career experience includes a comprehensive compensation and benefits package. Here are just a few reasons you’ll love working with us:

• Competitive compensation
• Comprehensive benefits
• Career success on your terms
• Flexible work environment
• Annual wellness and community outreach days
• Always on recognition for your contributions
• Global collaboration and networking opportunities

Proofpoint has been honored with six Best Places to Work Awards in 2024 by workplace culture leader Comparably, including Best Company Career Growth, Best Company Outlook, Best Global Culture, Best Engineering Teams, Best Sales Teams, and Best HR Teams.

We’re driven by a mission to stay ahead of bad actors and safeguard the digital world.

Our Culture

Our culture is rooted in values that inspire belonging, empower purpose and drive success-every day, for everyone. We encourage applications from individuals of all backgrounds, experiences, and perspectives. If you need accommodation during the application or interview process, please reach out to [e-mail].

Find your network, your allies, and your biggest fans. We know that work is simply better when you’re surrounded by people who inspire you—who share ideas, cheer you on, and genuinely want to see you succeed. That’s why we offer social circles, sponsored networks, and connection points across teams and time zones—to help you find your people, build your community, and thrive together. This isn’t just a job—it’s a mission to protect people and defend data in a world that never slows down. We’re building the future of human‑centric cybersecurity, and that future belongs to all of us. We take ownership, move fast, and hold ourselves accountable—because that’s what it takes to stay ahead. And we do it together, winning as one. Be empowered to reach your full potential through meaningful challenges and personalized support—designed around you and your goals. Whether you’re growing as a leader or leveling up from great to exceptional as an individual contributor, we’re here to help you get there.

Equal Opportunity Statement

Proofpoint is an equal opportunity employer, we hire without consideration to race, religion, creed, color, national origin, age, gender, sexual orientation, marital status, veteran status or disability.