Senior Backend Engineer (C#)

Salary Competitive
Equity To be negotiated

We're on a mission to improve the security of web applications around the globe and are looking for a Senior Backend Engineer to help us build the crawling and testing infrastructure of Heyhack.

If you are interested in designing and implementing algorithms, engineering smart scanning strategies, and joining a small team of passionate people, you might just be a perfect fit for us.

What you'll be doing

  • Developing Heyhack's crawling engine. Heyhack automatically scans web applications and tests for common vulnerabilities. We promise our customers that we can handle any kind of web app (independent of whether it's written in React, Vue.js, WebAssembly, or anything else). It's a hard challenge so we need to design and implement robust strategies that work generically across all web frontend frameworks.

  • Implementing test cases. We run a sophisticated suite of test cases on the web applications we scan. These cases include tests for SQL injection, cross-site scripting, click jacking, etc. We need to expand our test suite with tests for even more vulnerabilities.

  • Expanding our cloud infrastructure. We have designed a highly scalable setup in Amazon Web Services that can handle thousands of simultaneous penetration tests. We need to expand and maintain our infrastructure to keep up with the growing number of customers we expect to get.

  • Building the foundation for new products. Our current main product is Heyhack Scan—our automated penetration testing service. Soon, we will begin the development of Heyhack Protect—a next-generation web application firewall that uses the results produced by Heyhack Scan.

  • Working with passionate colleagues. We've just secured funding and are now scaling up our remote team of designers and engineers. You'll be working with super passionate people from across the globe.

What we need from you

  • Significant experience developing in C#.

  • Fluency in Modern .NET (i.e., .NET Core/.NET 6).

  • Knowledge of and experience with algorithms and data structures.

  • Some experience working with CI/CD pipelines (we use GitHub Actions).

  • Preferably, some experience working with Amazon Web Services.

  • You enjoy taking ownership and working in a fast-paced environment.

  • Based in a time zone within GMT-5 to GMT+3.

  • While not required, it's a plus if you have some experience in web application security. If you don't, it's okay—we'll teach you! 🙂

What we offer

  • Competitive salary.

  • Stock warrants in Heyhack.

  • 40-hour work week. 40 hours is plenty to do great work.

  • 100% flexibility. We're fully remote and don't have a fixed working schedule.

  • 5 weeks of paid time off a year.

  • Paid desk in a co-working space of your choice.

  • All the hardware you need to do your job (we personally love the M1 MacBook Pros).

  • Paid parental leave (matching the benefits provided by the Danish Act on Parental Leave, which are some of the best in the world).

For more information or questions please contact us at

Perks and benefits

This job comes with several perks and benefits

Free lunch
Free lunch

Enjoy a free catered lunch with your colleagues, every day.

Flexible working hours
Flexible working hours

Time is precious. Make it count. Morning person or night owl, this job is for you.

Free coffee / tea
Free coffee / tea

Get your caffeine fix to get you started and keep you going.

Equity package
Equity package

Want to be a partner? Look no further.

Maternity / paternity leave
Maternity / paternity leave

Kids are the future, go spend time with them.

Skill development
Skill development

We want to take you from good to great.

See all 12 benefits

Working at

Web security is becoming a bigger and bigger problem and the number of data leaks and ransomware attacks has increased exponentially in 2020 and 2021. Heyhack helps software companies improve the security of web applications by conducting automated penetration tests and offering advice on how to patch found vulnerabilities. We're a team of security-minded experts who have been working in information security for more then 15 years. We're on a mission to make the web a safer and more secure place and we're looking for talented people to join us on our journey. We're a fully remote team and we embrace the flexibility that working remotely allows. The founders (Sebastian and Anders) are based in Copenhagen and Aarhus, respectively, but we're hiring everywhere within the time zones GMT-5 to GMT+3. Wherever you're based, we're offering to pay for a desk in a co-working space, all the IT equipment you need, and a competitive compensation package that includes stock warrants for early team members, 5 weeks of paid time off, and paid parental leave.

Read more about Heyhack

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