Who We Are We are a leader in fraud prevention and AML compliance. Our platform uses device intelligence, behavior biometrics, machine learning, and AI to stop fraud before it happens. Today, over 300 banks, retailers, and fintechs worldwide use Sardine to stop identity fraud, payment fraud, account takeovers, and social engineering scams. We have raised $145M from world-class investors, including Andreessen Horowitz, Activant, Visa, Experian, FIS, and Google Ventures.

Our Culture

• We have hubs in the Bay Area, NYC, Austin, and Toronto. However, we maintain a remote-first work culture. #WorkFromAnywhere
• We hire talented, self-motivated individuals with extreme ownership and high growth orientation.
• We value performance and not hours worked. We believe you shouldn't have to miss your family dinner, your kid's school play, friends get-together, or doctor's appointments for the sake of adhering to an arbitrary work schedule.

We are hiring a Bot Detection Researcher/Engineer to help us strengthen our detection capabilities across our Web, iOS, and Android SDKs . This role is ideal for someone who enjoys understanding how real devices behave, how automation frameworks operate, and where the differences lie. You will research browser and mobile environments, explore evasion techniques, and uncover new ways to distinguish genuine users from automated or manipulated traffic.

What You Will Do

• Analyze how browsers and mobile operating systems expose signals that can be used to detect automation, spoofing, rooting/jailbreaking, and other forms of tampering.
• Examine frameworks such as Playwright, Puppeteer, Selenium, Appium, and mobile instrumentation tools to identify weaknesses and detection opportunities.
• Explore OS-level behaviors, sensor patterns, app lifecycle events, Web APIs, and device characteristics to find inconsistencies between real and synthetic environments.
• Build small prototypes or custom test harnesses to validate detection ideas and collect data from different platforms and OS versions.
• Work closely with Web, iOS, Android, and backend engineering teams to bring validated signals into our production SDKs.

What We’re Looking For

• Solid understanding of web internals, including JavaScript behavior, browser APIs, rendering differences, and WebView variations (100)
• Practical knowledge of iOS internals—system APIs, sensors, entitlements, app lifecycle, and common jailbreak indicators.
• Practical understanding of Android internals—system services, app architecture, rooting behavior, tampering techniques, and emulator characteristics.
• Experience reverse engineering or dissecting behavior in at least one environment (JavaScript, Android APKs, or iOS runtime).
• Familiarity with automation and botting tools and how they attempt to mimic real users.
• Ability to run independent research, test hypotheses, collect data, and clearly communicate results.
• Strong written and verbal communication skills.

Nice to Have

• Previous experience in bot detection, mobile security, fraud prevention, or device intelligence.
• Hands-on experience with Frida, Objection, LLDB, rooting/jailbreaking analysis, or instrumentation frameworks.
• Experience contributing to browser or mobile security projects.
• Comfort working with backend systems (Golang preferred) to help validate detection logic.
• Understanding of behavioral biometrics and how they complement device-level signals.

Tech Stack

• Web SDK: TypeScript
• iOS SDK: Swift
• Android SDK: Kotlin / Java
• Backend: Go (Preferred)
• Infrastructure: GCP / AWS

Why This Role Matters Automation is no longer limited to browsers—mobile automation is becoming just as sophisticated. This role plays a key part in ensuring our Web, iOS, and Android SDKs stay ahead by identifying subtle, reliable signals that reflect how real devices behave.

Benefits We Offer

• Generous compensation in cash and equity
• Early exercise for all options, including pre-vested
• Work from anywhere: Remote-first Culture
• Flexible paid time off and Year-end break
• Health insurance, dental, and vision coverage for employees and dependents - US and Canada specific

Join a fast-growing company with world-class professionals from around the world. If you are seeking a meaningful career, you found the right place, and we would love to hear from you.

To learn more about how we process your personal information and your rights in regards to your personal information as an applicant and Sardine employee, please visit our Applicant and Worker Privacy Notice .