Senior Systems Engineer - Application Security

Role overview Drive the design and operation of application security services that protect web properties for millions of customers. Work is deeply engineering-focused: writing code, shaping architecture, and keeping production systems healthy at internet scale (up to 100 million requests per second). The position blends hands-on systems engineering with security awareness, supporting a portfolio that includes web application firewall, page protection, asset management, and API shielding capabilities.

Responsibilities - Design and build distributed services following modern best practices, and review technical specifications, design docs, and code from peers. - Deploy and operate production systems at very high scale, taking regular on-call shifts as part of a rotation. - Track emerging threats to web applications and translate those trends into product and engineering improvements. - Mentor and grow other engineers through code review, knowledge sharing, and pairing. - Partner with engineering and product counterparts to align on roadmaps and deliver cross-team initiatives.

Requirements - At least 5 years of professional experience as a hands-on software developer. - Proficiency in Go or Rust, with exposure to devops tooling such as Kubernetes, Salt, Kafka, or Systemd. - Strong Linux or Unix fundamentals and meaningful experience with distributed systems at scale. - Solid testing and documentation discipline, comfortable owning services end-to-end.

Nice to have - Cybersecurity background or experience building security-relevant products.

Benefits and work setup - Hybrid schedule with two days per week in office; available locations include Amsterdam, Brussels, Lisbon, London, Munich, Paris, Sweden, and Switzerland. - Unlimited paid leave, with leaders modeling real time off. - Equity grants on joining plus performance-linked refreshers. - Medical and dental insurance, mental health support, life insurance, and a defined-contribution pension. - Lisbon-based base salary range of approximately $66,000 to $91,000, with location-based adjustments.