January 2026: Systemd cryptography memory-management hardening. Key feature delivered: Introduced safe_mlockall to conditionally call mlockall only when the process has CAP_IPC_LOCK, preventing OOM in unprivileged processes during cryptographic operations. Major bug fix: mitigated RLIMIT_MEMLOCK-triggered OOM in cryptenroll/cryptsetup/shutdown by gating mlockall behind capability checks (commit 465f6a62840df58d4cf3fc48c2bbdb2fa0ac99b1). Impact: improved reliability and memory security of cryptographic workflows across the yuwata/systemd stack, especially in constrained environments. Technologies/skills demonstrated: capability checks, secure memory management, cryptography workflow hardening, code changes across systemd cryptography components.

In 2025-10, I focused on stabilizing cross-environment builds in NixOS/nixpkgs by delivering targeted CMake compatibility fixes for the Soapy driver family and upgrading the libbladeRF stack. The work spanned backporting and patching multiple packages to maintain compatibility across a wide range of CMake toolchains, and upgrading core library components to align with upstream changes. This reduces build failures, simplifies downstream maintenance, and improves developer onboarding across platforms.