Senior Penetration Tester
Description
We invite a Senior Penetration Tester to join our team. It's an office-based role – no remote or hybrid options.
Responsibilities
- Lead end-to-end penetration testing engagements across web applications, APIs, mobile, internal and external networks and cloud (primarily AWS).
- Run red-team and assumed-breach operations - initial access, privilege escalation, lateral movement, persistence, exfiltration - including against fraud and detection stacks.
- Perform security reviews of cloud-native services, Kubernetes workloads, CI/CD pipelines, and microservices.
- Discover and exploit vulnerabilities across real-money flows - payments, deposits and withdrawals, wallets, KYC / AML, bonus systems, and affiliate tracking.
- Partner with product, engineering, AppSec, payments, and fraud teams to translate findings into concrete fixes and durable controls.
- Develop custom tooling, scripts, and methodology where no out-of-the-box approach exists.
- Build and validate declarative threat models and contribute to "secure by design" practice.
- Mentor mid and junior testers, review their engagement plans and reports.
- Track new CVEs, TTPs, MITRE ATT&CK updates, and regulator advisories - translate them into concrete changes here.
- Support pre-sales scoping, effort estimation, and pre-certification engagements for new products and jurisdictions.
- Serve as a trusted offensive-security advisor to product, engineering, and compliance teams.
Requirements
- Minimum 4 years of hands-on penetration testing or offensive-security experience.
- Proven track record across at least three of: web / API, internal, external network, cloud (AWS / GCP), mobile (iOS / Android).
- OSCP or an equivalent in-the-box certification.
- Strong working knowledge of SAST/SCA/DAST tooling, AWS/GCP, MITRE ATT&CK, OWASP ASVS / WSTG, PTES.
- Understanding of the data flow, MVC model.
- Understanding of supply chain attacks.
- Good reporting skills.
- Comfortable scripting in Python plus Bash.
- Knowledge at least one of major cloud provider's IAM model.
- Experience pentesting cloud-native systems and Kubernetes environments, plus the CI/CD pipelines around them (GitLab, GitHub Actions, Jenkins) and IaC (Terraform, Helm, CloudFormation).
- Strong written and verbal communication in English .
- Experience balancing security and business demands under release pressure.
- Familiarity with industry regulations, frameworks, and practices: PCI DSS, ISO 27001, NIST, GDPR .
## PREFERRED QUALIFICATIONS:
- One of offensive-security certifications: OSWE, OSEP, OSED, CRTO, BSCP, ARTE, GRTE .
- In-depth experience architecting secure services on Kubernetes and AWS.
- Prior iGaming, fintech, or payments domain experience.
- Public CVEs, advisories, write-ups, conference talks.
- HTB Pro Lab completions, real CTF placements.
- Open-source contributions to offensive or defensive tooling.
Benefits
- 24 vacation days annually.
- 6 sick days without a medical certificate.
- Premium Health Insurance (coverage up to 5,000 EUR annually).
- Special occasion gifts: birthday, wedding, newborn.
- Learning & Development budget (for conferences, courses and certifications).
- Corporate events: international parties, team buildings, activities.
- Career growth opportunities in a fast-growing company.
- Relocation package for international candidates.
- Sports package (FitPass membership).
- Language classes: Serbian & English (company-covered).
