[[Exclusive] After five years, recruitment clues spell out a complete map: ByteDance is quietly restarting mobile phone research and development] According to the monitoring of Activision Beating, five years after the closure of nut mobile phone business, ByteDance is re entering the underlying research and development of smart phones through a new form. This inference comes from the dragnet data sorting of the full number of posts in the official recruitment system of ByteDance. After comparing the specific responsibilities of hundreds of low-level positions, the fact is very clear: ByteDance is not just focused on developing lightweight end-to-end AI applications, but is building a complete set of mobile level software and hardware foundations; Refactoring the interaction between the upper level Agent and the Android/RTOS system, while the lower level focuses on structural stacking, baseband, and communication networking, and has delved into the NPI (New Product Import) trial production stage of aligning the OEM production line. On the hardware development and mass production side, the array arrangement of bytes goes straight to the deep waters of the hardware supply chain. The Shenzhen R&D nodes located in the hinterland of the supply chain are intensively releasing positions for complete machine technology, PCB high-speed interconnection, testing technology, and hardware baseband, fully connecting with the OEM production line. Among them, the position of structural engineer requires coverage of new machine stacking, middle frame, battery cover, and shaft design, with flagship machine hardware development experience such as "folding screen", "LIPO packaging", and "IP68/IP69K" listed as additional items; The position of whole machine process requires mastery of DFM/DFA/DFS analysis, NPI trial production introduction, AOI testing, dispensing and spot welding processes. Such job portraits are completely decoupled from ordinary Internet software development, presenting a distinctive color of a large hardware factory for the whole machine. At the system base end, Android system experts stationed in Beijing will coordinate the entire process from project initiation, system solution, integrated development to mass production delivery. Their responsibilities cover ODM/OEM docking, Android Framework, HAL, vendor interface adaptation, and Qualcomm platform tuning, and even need to control factory flashing, aging, and production line testing. At the same time, the mobile OS team is comprehensively recruiting SoC chip adaptation, BSP, RTOS kernel, WiFi driver, graphics engine, system power consumption, and DFX experts, almost dismantling the underlying system skeleton of a smartphone and completely restructuring it. The most direct breakthrough occurred in the "Doubao Mobile Assistant" team, which was originally considered a pure software project by the outside world. The research and development focus of the Doubao mobile assistant team is shifting towards the hardware bottom layer, with positions covering touch drivers NFC、 System thermal management, peripheral BSP, audio system, and sensor fusion. The core signal is that the team is recruiting for the position of Telecommunications RIL modem product architect, which requires experience in delivering cellular networks from Qualcomm or MediaTek (MTK), familiarity with telephony systems, RIL drivers, field testing, CTA certification, and RF antenna development rhythm. This indicates that ByteDance's research and development boundary has crossed the pure application layer and entered the core communication baseband and wireless RF fields of mobile phones. On the upper level interaction side, AI is reshaping the human-computer interaction interface. The Agent software architect in the Mobile OS department will be responsible for designing a multi-agent collaborative interaction framework that connects internal and external agents using a unified standard protocol to achieve low latency, multimodal dynamic decision-making; The perception and memory algorithm position of the Doubao mobile assistant focuses on users' long-term memory, multimodal perception, and proactive service mechanisms. This confirms a deeper strategic ambition: ByteDance is not satisfied with delivering Doubao as a pre installed app to terminals, but is attempting to reshape Doubao as the primary entry point for the entire hardware system. [Original link]