Nathan conducts resilience and fault-tolerance research with research scientists, students, and visiting professors. Among interests in hardware reliability, algorithmic design, and a general interest in computing on (perhaps extremely) unreliable hardware, Nathan is project lead of the Fine-Grained Soft Error Fault Injection (F-SEFI) framework. F-SEFI is a tool for exploring how real applications running on real systems tolerate emulated soft errors. The tool injects soft errors with extreme precision at specific points in a running application on real hardware, with real OS kernels, and real middleware. F-SEFI builds on an open source virtual machine and processor emulator to emulate faulty hardware but does so only in ways to affect the application of interest, thereby making it more tractable to study how applications respond to specific types of soft errors. Additionally, Nathan conducts field studies on DOE supercomputers to study memory and processor resilience including correctable faults and uncorrectable errors.