Humans first
Automation finds the noise. Experienced testers find the breach.
Hackers with a conscience.
Founded in 2014 by three penetration testers who were tired of PDF reports nobody read. Today we are 64 people across Lisbon, Austin and Remote.
Our story
Security work that changes something.
Sentinel started in a Lisbon co-working space with one rule: every finding must come with a fix a developer can actually ship. Twelve years later that rule still decides how we hire, test and report.
We are independent and employee-owned. We do not resell tools, take vendor kickbacks or outsource testing. When we recommend a product, it is because we use it ourselves.
Principles
What we refuse to compromise on.
Fix, don't scare
No FUD, no 400-page reports. Clear risk, clear remediation.
Radical discretion
Client names are never used without written consent. Ever.
Always learning
Every engineer gets 20% research time and a conference budget.
Leadership
The people on your bridge call.
Marcus Hale
CEO · ex-NCSCTwenty years in offensive security, former red team lead at the UK NCSC.
Elena Vos
Head of Red TeamOSCE3, speaker at DEF CON and Black Hat Europe.
Daniel Okafor
SOC DirectorBuilt the 24/7 SOC from four analysts to forty.
Priya Raman
Head of GRCHas guided 90+ companies through SOC 2 and ISO 27001.
Rafael Costa
IR LeadLed response on 300+ ransomware and BEC incidents.
Timeline
Twelve years, zero shortcuts.
2014
Founded in Lisbon by three pentesters.
2017
CREST accreditation and first 100 clients.
2019
24/7 SOC launches with follow-the-sun coverage.
2022
Austin office opens; incident response retainer launched.
2026
64 people, 410 clients, still employee-owned.
Credentials
Certified where it counts.
Our people hold 180+ active certifications. The firm itself is independently audited every year.
OSCPOSCE3CREST CRTGIAC GCIHCISSPCCSP
Careers
Join the blue and red teams.
We are hiring a senior cloud pentester, two SOC analysts (Lisbon) and a detection engineer (remote, EU or US time zones).
