Senior Backend Engineer
Location: Barcelona (On-site)
About the Company
Our client is a fast-growing cybersecurity company based in Barcelona, redefining digital security standards in the B2G (Business to Government) space. They are on a mission to address some of the most complex and sophisticated challenges in the cybersecurity landscape.
At its core, the company is driven by a strong purpose: creating technology that contributes to a safer world. Their culture is built on collaboration, curiosity, and continuous learning, within an environment where every individual’s contribution matters and makes an impact.
The Role
We are looking to hire a Senior Backend Engineer, a true coding Superstar, to join their growing engineering team. The selected candidate will play a key role in designing, developing, and maintaining scalable backend systems that power their cybersecurity platform.
This is a highly technical position that combines ownership, impact, and the opportunity to contribute directly to the company’s mission of advancing cybersecurity innovation.
Key Responsibilities
* Design, develop, and maintain backend services using Python and C
* Build and optimize microservices-based architectures ensuring scalability, performance, and security
* Work with SQL and NoSQL databases (e.g. PostgreSQL, MongoDB)
* Develop and deploy containerized applications using Docker
* Debug, profile, and improve existing systems to ensure stability and optimal performance
* Collaborate with cross-functional teams (Frontend, DevOps, Research, and Product) to deliver end-to-end solutions
* Ensure code quality through testing, code reviews, and adherence to engineering best practices
* Participate in system design discussions, proposing architectural improvements for scalability and maintainability
* Take ownership of the full development lifecycle, from requirements gathering to deployment and monitoring
1. Requirements
* 5+ years of professional experience in backend development, with a strong record of building scalable systems
* Advanced proficiency in Python (core backend language)
* Solid experience with C programming and internal OS development concepts
* Strong understanding of system architecture and distributed systems
* Hands-on experience with Docker and containerized environments
* Proficiency in both SQL and NoSQL databases
* Familiarity with DevOps practices and on-premise infrastructure is a plus
* Good understanding of Linux-based systems
* Ability to work autonomously, take ownership, and deliver high-quality solutions
* Excellent communication skills and fluency in English (written and spoken)
* Availability to work on-site in Barcelona, within a collaborative and fast-paced environment
What’s on Offer
Our client offers a people-first environment within an ambitious and fast-growing start-up, providing strong opportunities for technical growth and real impact in the cybersecurity space.
💡 You will enjoy:
* Top salary package for a Top Profile
* Private health insurance
* Flexible compensation plan (including fully covered meal vouchers)
* Flexible working hours
* 100% on-site role in their beautiful office (Barcelona), due to security reasons
* Fully stocked kitchen (coffee, organic fruit, snacks, beverages)
* Team-building activities and continuous learning opportunities
👉 If you’re looking for a role where your work has real impact and you want to be part of a cutting-edge cybersecurity project, this is the perfect opportunity.