Sr. Application Security Engineer

About the Position

Protect the trust of millions of families as you shape application security across Lingokids’ apps and services, building safer experiences for children from the start.

Responsibilities

• Own application security across our React Native app, Ruby backend services and APIs, and AWS infrastructure.
• Run threat modeling and design reviews with squads on new features and architecture changes.
• Build and maintain security tooling in CI/CD: SAST, dependency scanning, secrets detection, mobile app analysis.
• Strengthen our software supply chain: third-party SDKs, open-source dependencies, build pipeline integrity.
• Find, triage and fix vulnerabilities, hands-on in the code when needed.
• Run or coordinate penetration tests and turn findings into fixes.
• Work with Legal and Privacy so our apps meet kids privacy requirements (COPPA, GDPR) in practice, not just on paper.
• Raise the security baseline of the engineering team through guidelines, reviews and practical training.
• Take part in security incident response.

Requirements

• 5+ years in security engineering, with a strong focus on application security in a product company.
• Hands-on mobile application security experience, ideally with React Native, and familiarity with OWASP MASVS / ASVS.
• Ability to read, review and write code; Ruby and/or JavaScript / TypeScript preferred.
• Experience integrating security tooling into CI/CD pipelines.
• Solid understanding of web and API security, authentication and authorization.
• Judgment to prioritize real risk over theoretical findings, and the communication skills to get engineers on board.

Nice to Have

• Native iOS and/or Android security experience.
• AWS security experience (IAM, network controls, security services).
• Experience with privacy regulation affecting kids products (COPPA, GDPR-K, KidSAFE).
• Software supply chain security (SBOM, dependency pinning, signed builds).
• Certifications such as OSCP, OSWE or GWAPT.

We Offer

• Career Growth: Up to €2,000 per year for books and training.
• Remote in Spain & Relocation-Friendly: Work from Spain or relocate with our support.
• Stock Options: Opportunity to own part of the company.
• Home Office Setup: €400 allowance for setup and €35/month for remote work expenses.
• Meal Allowances: €60/month on your Cobee card.
• Flexible Compensation: Manage meal, transport, and childcare expenses with Cobee.
• Health Insurance: Private health coverage at exclusive rates.
• Language Lessons: Free classes in Spanish and English.
• Visa Sponsorship: We handle the process and cover the costs for EU visa.

About the Company

We're Lingokids, the #1 entertainment platform for young kids. We create experiences little ones genuinely love. Everything we make is created in-house to be seriously fun, with the good stuff built in from the very beginning. We're KidSAFE certified, completely ad-free, and committed to giving families entertainment they can trust, with no compromise. Ever.

20 million kids come back to us every single month, and we’ve earned more than 50 awards along the way. Now we're going after something bigger: becoming the go-to entertainment destination for kids everywhere, and changing what content looks like for the generation growing up on it.

Passion matters more than perfection

Didn’t check every box for this role? No worries! We’re looking for passionate, driven individuals who believe in our mission. If that sounds like you, we’d still love to hear from you!

Diversity, Equity, and Inclusion

At Lingokids, diversity isn’t just a checkbox-it’s at the heart of everything we do. Just like we teach kids to embrace differences, we celebrate them in our team, knowing that the best ideas come from unique perspectives. We’re all about creating a space where everyone feels valued, heard, and empowered to be their authentic selves. No matter your background, identity, or story, if you’re passionate about making a difference in education, we want you here.