Sr. Application Security Engineer

Lingokids; Madrid; Remote; EUR 70,000 - 90,000; Full time

Benefits offered by this job

Health insurance

Remote in Spain

Relocation support

Stock options

Home office allowance

Meal allowances

Language classes

Visa sponsorship

Team offsites

Job summary

Lingokids in Spain is hiring a Senior Application Security Engineer to own the security of our React Native app, Ruby backend services and AWS infrastructure. You will design threat models, review architecture, and implement secure tooling in CI/CD.

You’ll strengthen supply chain security, triage vulnerabilities and coordinate penetration tests, working with Legal to meet COPPA and GDPR requirements. Fluency in English is essential in our fully remote, multinational team.

Qualifications

• 5+ years in security engineering in a product company.
• Hands-on mobile app security experience, ideally React Native.
• Ability to read, review and write code (Ruby and/or JavaScript/TypeScript).

Responsibilities

• Own application security across React Native app, Ruby backend and AWS infrastructure.
• Run threat modeling and design reviews for features and architecture changes.
• Build and maintain security tooling in CI/CD: SAST, dependency scanning, secrets detection, mobile app analysis.
• Strengthen software supply chain: SDKs, open-source deps, build integrity.
• Find, triage and fix vulnerabilities; hands-on in code when needed.
• Run or coordinate pentests and translate findings into fixes.
• Work with Legal/Privacy to meet COPPA and GDPR in practice.
• Raise security baseline via guidelines and training.
• Participate in security incident response.

Skills

Security engineering

Mobile security

React Native

MASVS/ASVS

JavaScript/TypeScript

CI/CD tooling

Web/API security

Communication skills

Tools

AWS

SAST tooling

Job description

We've set the standard in kids entertainment. Come help us raise it.

We're Lingokids, the #1 entertainment platform for young kids. Most kids content is designed to capture attention. 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.

You in? Keep on reading.

The role

We're hiring a Senior Application Security Engineer to own the security of the Lingokids apps and the systems behind them. Millions of families trust us with their kids' time, and keeping that trust is part of the product. You'll work inside our engineering teams, making the secure path the easy path, not acting as a gate at the end.

What you’ll do

• 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.

What you’ll bring

• 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.

English is a must

We're a multicultural team building in English, so while certifications aren't necessary, fluency is. And since we're fully remote, clear communication matters as much in writing as in speaking, especially in the long-form, async formats that keep a distributed team working well together.

Life at Lingokids

Career Growth: Your growth drives our success! We invest in your development up to €2,000 per year for books and training; so you can keep learning and growing with us.

Remote in Spain & Relocation-Friendly Work from wherever you’re most productive, whether that’s your home anywhere in Spain or our vibrant hub in Madrid. Not currently in Spain? We’d love to have you here! We actively encourage relocation for those looking to make Spain their new home base.

Stock Options: Your contribution matters! You'll receive stock options, giving you the opportunity to own part of the company and share in its success.

Home Office Setup: Create your ideal workspace with a €400 allowance for setup and €35/month for remote work expenses, because comfort fuels creativity!

Meal Allowances: Get €60/month on your Cobee card to enjoy meals at restaurants or food delivery, good food makes everything better!

Flexible Compensation: Manage your meal, transport and childcare expenses easily with Cobee, integrating them directly into your payroll.

Health Insurance: Access private health coverage at exclusive rates through Adeslas, seamlessly deducted from your payroll, quality care made simple.

Language Lessons: Learning never stops! Enjoy free language classes in Spanish and English, to sharpen your skills and stay connected in a global team.

Visa Sponsorship: If you need a visa to work in the EU, we’ll handle the process and cover the costs to make your transition seamless.

Company events: Yes! We’re a fully remote team spread across different countries, but we love getting together from time to time in different corners of Spain, for team gatherings and recharging at our amazing off-sites!

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.