Senior Software Engineer - Android Systems & Security

**About PayJoy**

PayJoy, a Public Benefit Corporation, is a mission-first credit provider dedicated to helping under-served customers in emerging markets to achieve financial stability and success. Our patented technology for secured credit provides an on-ramp for new customers to enter the credit system. Through PayJoy’s point-of-sale financing and card offerings, customers gain access to a modern quality of life. PayJoy’s credit also allows our customers to seize opportunities as micro-entrepreneurs, and acts as insurance for tough times. Through our cutting-edge machine learning, data science, and anti-fraud AI, we have served over 18 million customers as of 2025 while achieving solid profitability for sustainable growth.

**This role**

This is **not** a conventional Android app development role (building applications for the Play Store). We are seeking a specialized systems engineer focused on the heart of the operating system: **AOSP (Android Open Source Project)** and the **TEE (Trusted Execution Environment)**.

In this role, you will bridge the gap between high-level Android features and low-level hardware integration, ensuring our proprietary security mechanisms—which protect our assets at the OS level—are robust, performant, and tamper-proof.

### Responsibilities

• 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

• **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.

💬 **Ready to solve complex engineering challenges that almost no one else in the industry is tackling?** Apply directly or send me a DM. Let's chat!
### Benefits

• 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