Senior Software Engineer – Android Systems, Security

PayJoy

Specialized systems engineer focusing on AOSP and TEE for PayJoy’s credit solutions. Bridging high-level Android features with low-level hardware integration for security mechanisms.

Posted 6/6/2026full-timeSan Francisco • California • 🇺🇸 United StatesSenior💰 $272,000 - $283,000 per yearWebsite

Tech Stack

Tools & technologies

AndroidJavaKotlinPython

About the role

Key responsibilities & impact

Framework Engineering: Develop and maintain custom modifications within the Android Framework (AOSP) and Hardware Abstraction Layers (HAL).
OEM Integration: Partner with global smartphone manufacturers and chipset vendors to integrate PayJoy’s proprietary technology into factory firmware.
Cross-Border Collaboration: Work daily with our China-based engineering team to align on technical specifications and manufacturing requirements.
Feature Development: Implement new locking features that interact with system-level services for example Telephony, Power Management, and Device Policy Manager, etc…
R&D & Debugging: Use deep chip-level knowledge to troubleshoot integration issues across different silicon providers (Qualcomm, MediaTek, etc.).
Process Automation: Contribute to OTA (Over-the-Air) updates and global device testing.

Requirements

What you’ll need

**Android Internals Expertise:** Extensive, hands-on experience with AOSP development, including modifying system services and utilizing the Android build system (Soong/Make).
**Low-Level Language Mastery:** Expert-level proficiency in **Java and C/C++ (JNI)**. (Ability to read/write Kotlin is expected, but core work remains at the system level).
**OEM/Firmware Background:** Proven experience working with or for an OEM or chipset vendor on firmware customization, device bring-up, or security hardening.
**Strong Core Skills:** Demonstrable knowledge of **AOSP and TEE / ARM TrustZone**.
*⚠️ Note:* If your background is primarily focused on building consumer-facing commercial apps (e.g., banking, gaming, or general retail apps), this role will not be a match for your skillset.
🌟 Desirable Skills (Pluses):
Experience with Secure Boot, verified boot (AVB), and common Android exploit vectors.
Automation of firmware build pipelines and signing processes using Python or Bash.
Comfort collaborating effectively with international teams across different time zones.

Benefits

Comp & perks

Local benefits depending on the country of hire
Company-funded health insurance for employee and immediate family
Company-funded employee life and disability insurance
Paid vacation days, unlimited sick leave
$2,000 USD annual Co-working travel perk
$2,000 USD annual Professional Development perk
Phone finance, headphone benefit, home office equipment allowance and wellness perks
Catered lunches

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills & Tools

AOSP developmentJavaC++KotlinAndroid build systemSecure Bootverified bootPythonBashARM TrustZone

Soft Skills

cross-border collaborationcommunicationtroubleshootingteam alignmentinternational collaboration