Senior Backend Engineer (Offensive Security Platforms)

Are you obsessed with building high-performance systems that can outsmart the world’s most sophisticated hackers?

Then look no further, and join us here at Hadrian as a Senior Backend Engineer focusing on building our offensive security platforms!

Who are we:

We are Hadrian - an offensive cybersecurity startup. We are reshaping the future of cybersecurity through the power of agentic AI injected with the hacker’s perspective. Founded in August 2021, we've secured funding and the backing of ABN AMRO Ventures and Cherry Ventures, propelling us into a new era.

Our goal is to provide companies with an autonomous Threat Exposure Management platform. At Hadrian, we view security through a hacker's eyes because hackers understand hackers best. We continuously map the digital footprint of organisations, discover risks, and prioritise remediation for security teams to harden their external attack surfaces.

Located in Amsterdam's buzzing Leidseplein, by London's famous Paddington Station, and our most recent US HQ in the heart of New York City, our diverse team from 25+ countries is on a mission to shake things up in offensive security. Join us in making waves and securing over 700 businesses, and be at the forefront of automated offensive security.

Your Role:

As a Senior Backend Engineer at Hadrian, you will design and implement high-performance backend services and distributed systems that power our offensive security platform. You will work on autonomous systems capable of scanning, analyzing, and validating vulnerabilities at internet scale, moving beyond traditional scanning into intelligent, agentic security operations.

This role is ideal for engineers who combine deep backend engineering expertise with a hacker mindset. We’re looking for someone who enjoys solving complex scalability challenges, building resilient event-driven architectures, and thinking like an attacker to anticipate edge cases before they happen.

If you enjoy working across disciplines to build autonomous security systems that operate at internet scale, and want to help push offensive security beyond human speed and capability, we would love to hear from you!

What you will do as a Senior Backend Engineer at Hadrian:

• Develop and maintain event-driven components that orchestrate and execute core offensive security strategies.

• Translate offensive security strategies into robust, high-quality code.

• Architect and deploy backend services that power our Agentic AI capabilities, moving beyond simple scanning to intelligent, multi-step exploit validation.

• Write low-level, high-concurrency tools in Go and Python while maintaining robust, scalable APIs.

• Design data pipelines capable of handling massive internet-wide reconnaissance data using Apache Kafka and Kubernetes/KNative.

• Leverage your expertise to shape architectural decisions and align technical strategies with business goals.

• Take on a unique challenge. We’re on a mission to uncover the most urgent security flaws in our customers' attack surfaces in real-time. You’ll help us build our innovative platform, operating at an internet-wide scale.

You are fit for this job because you:

• Have 4+ years of experience building large-scale distributed systems, features or applications.

• Are proficient in languages such as GoLang, Python, C#, or similar technologies, and have experience working with PostgreSQL.

• Have a background in cybersecurity.

• Use AI pragmatically to accelerate development workflows, automating the “good enough” so you can focus on mission-critical security architecture and complex engineering challenges.

• Have exceptional problem-solving abilities, with the grit to investigate and resolve deep-seated production bottlenecks.

• Enjoy solving complex scalability and performance challenges in distributed environments.

• Communicate with clarity, bridging the gap between technical complexity and product mission.

• Share our values and work in accordance with them

Bonus points if you have:

• Experience in DevOps / DevSecOps environments using Kubernetes, Knative, or Kafka.

• Hands-on experience with Agentic AI frameworks or building autonomous agents.

• Experience with Python and TypeScript.

• Are an expert in Scalability: You have a track record of building systems that don't just work, but perform under extreme load.

• Deep experience with database scaling, especially PostgreSQL and Neo4j.

• Contributions to open source projects.

Our stack:

• GoLang

• Python

• Knative Serving / Kafka

• Docker / Kubernetes / Helm Charts

• C#

• PostgreSQL

• .NET Core

• AWS

• Typescript (NextJS / ReactJS)

Benefits at Hadrian:

• Unlimited paid holiday

• Stock options package

• Mobile phone stipend

• Work-from-home budget

• Business travel card

• Swapfiets

• Referral bonuses

Why you want to be part of Hadrian:

Make the internet safer: We enable companies to protect their customers, employees, and other stakeholders from malicious hackers by providing real-time Exposure Management from the Hacker’s perspective

Board a primed rocket ship: Hadrian is growing fast; the team is approaching 90 wonderful people, notable customers are signed, and significant funding is raised. Now is the time to join our high-growth journey

Be part of a strong and dynamic culture: Our values define who we are as a group and serve as the cornerstones to guide us in building a product that our customers love. At Hadrian, we achieve this by championing a culture that takes ownership, succeeds together, increases velocity, and pursues growth

Sounds like the role for you? Hit the apply button!

Our customers are seeking a world-class and reliable digital security service. That is exactly what we are offering. Therefore, a background check will be part of the process.