Ondrej contributed to the flipperdevices/flipperzero-firmware repository by expanding the NFC key dictionary, focusing on enhancing interoperability and device coverage. He replaced the existing mf_classic_dict.nfc file with a Proxmark3-derived dataset, integrating a broader range of known NFC keys into the firmware. This work involved careful data management and a deep understanding of NFC protocols, ensuring that the firmware could support a more diverse set of keys across various applications. By leveraging NFC technology and data integration skills, Ondrej laid the foundation for future improvements in the firmware’s NFC subsystem, addressing both current needs and anticipated future requirements.