Month: 2026-04 focused on stabilizing secure-build workflows for NRF91 by propagating the Anomaly 36 workaround through TF-M. Key change propagates CONFIG_NRF91_ANOMALY_36_WORKAROUND to system_nrf91_approtect.h, enabling the anomaly workaround in secure builds and ensuring correct functionality in production-like scenarios where the workaround is required. The change includes explicit caution that this setting should not be left enabled in production due to potential sleep-state impacts. Delivered in the nrfconnect/sdk-nrf repository with commit bf91ca9bd5925d521bc60f1538d9beeb090df9ee.

Concise monthly summary focusing on key accomplishments for 2026-02 in the nrfconnect/sdk-nrf repository.

January 2026 monthly work summary focusing on PPP MRU/MTU negotiation improvements across Zephyr and NRF from-tree integration, improving PPP reliability and MTU discovery.

In August 2025 (Month: 2025-08), delivered targeted RAM optimization for Thingy boards in the serial LTE modem app and fixed a CMUX/AT command handling bug in the dialup flow for the nrfconnect/sdk-nrf repository. The RAM optimization reduces buffer usage when CMUX is enabled, freeing RAM for PPP and modem trace functionalities and ensuring buffers match hardware configurations on Thingy boards. The CMUX/AT command fix ensures OK responses are sent on the same channel as the request, correcting AT command channel management in the CMUX driver. Together, these changes improve runtime performance, reliability of cellular connections on Thingy devices, and overall system stability.

July 2025 monthly summary for nrfconnect/sdk-nrf focused on performance and compatibility improvements in the Serial LTE Modem stack. Key delivery: switched the Serial LTE Modem to the downstream SLM UART backend, replacing the generic UART backend with an SLM-specific backend to optimize performance and compatibility in downstream deployments. This involved updates to configuration and source to align with SLM expectations, enabling better throughput and reliability for modem communications. Major bugs fixed: None reported in the provided data. Overall impact and accomplishments: Delivered a targeted backend integration that reduces runtime overhead, improves compatibility with downstream SLM configurations, and lays the foundation for future SLM optimizations. The change supports smoother production deployments and contributes to system stability in modem communication workflows. Technologies/skills demonstrated: NRF SDK (nrfconnect/sdk-nrf), C, UART backend integration, downstream/backend-specific configuration, code refactoring for backend specialization, and change management for configuration updates.

June 2025: Delivered reliability hardening and feature refactors across the LTE modem stack and GPIO subsystems, focusing on data efficiency, power stability, and maintainability. The work enhances device uptime in real-world idle/resume scenarios, reduces risk during abnormal conditions, and provides a solid foundation for future async/polling enhancements while tightening resource management across components.

May 2025 monthly summary: Delivered critical improvements across cellular modem integration, PPP reliability, and data handling, driving stability, performance, and developer productivity. Notable work includes: SLM Shell RTS/CTS pin documentation alignment to prevent user misconfigurations; Cellular modem PPP link control integration to avoid unnecessary PPP restarts; robust PPP stack enhancements including action queuing, hardware flow control, receive buffer alignment, graceful shutdown, and CMUX improvements; UDP data mode reliability fix to prevent packet splitting; and AT#XAPOLL support for asynchronous socket event monitoring. Additionally, introduced a dormant state for cellular PPP with asynchronous termination to gracefully recover from network loss and improved suspend handling to ensure carrier off closure of resources.

April 2025 monthly summary for the nrfconnect/sdk-nrf: Delivered targeted reliability and compatibility enhancements for Thingy:91 X and the modem_slm stack, along with documentation hygiene improvements for serial LTE modem options. The work focused on business value: maintaining device compatibility, reducing freezes and data loss, and providing accurate guidance to developers, enabling faster integration and fewer support escalations.

March 2025 performance summary for nrfconnect/sdk-nrf focusing on reliability, data integrity, and documentation. Key outcomes include stabilizing Serial LTE Modem by offloading UART messaging and fault handling from ISR to a work queue, updating Trusted Firmware M to address protected-storage data loss, and delivering a comprehensive SLM documentation overhaul that clarifies data mode flow, config usage, and testing procedures for TCP/UDP/TLS/DTLS client functionality. These changes reduce runtime asserts, mitigate secure-storage risk, and improve developer onboarding and test coverage.

February 2025 monthly summary for nrfconnect/sdk-nrf focusing on Sysbuild improvements around APPROTECT configuration and NRF54LX support. Delivered NRF54LX-specific APPROTECT options with conditional protection application, fixed a build dependency bug for APPROTECT configurations, and updated AP-Protect documentation to reflect NRF54L support. These changes enhanced build reliability, security configurability, and developer guidance across the NRF54LX platform.

January 2025 monthly summary across three repositories (zephyrproject-rtos/trusted-firmware-m, NordicBuilder/sdk-nrf, nrfconnect/sdk-nrf). Focused on reliability, security and modernization to deliver business value through robust protected storage, stable modem operations, and updated firmware workflows.

December 2024 monthly summary for NordicBuilder/sdk-nrf focusing on a targeted bug fix in LTE Modem Datamode quit string handling. The change prevents mis-termination when incoming data resembles the quit string, thereby improving robustness of serial LTE modem datamode parsing and avoiding data processing errors. Implemented as a focused patch with a single commit to minimize risk and maintain code health. This work supports reliability and stability goals for connected devices, reducing field failures and support loads.

Month: 2024-11 — Performance review summary for software development across NordicBuilder/sdk-nrf and zephyrproject-rtos/trusted-firmware-m. Key focus areas this month were: reliability improvements for wireless modules, tighter integration of trusted firmware components, and enhancements to storage APIs for better data management. The work delivered tangible business value by increasing system reliability, simplifying configuration and maintenance, and expanding the usable capabilities of the Protected Storage layer. Key achievements (top 3-5): - Serial LTE Modem reliability improvements and AT command cleanup: increased serial_lte_modem connection timeout from 3 seconds to 30 seconds to reduce premature connection failures; refactored AT command definitions to simplify registration and reduce redundancy. Commits: c98bffa6324f8c261f87b4b9dadb8bf5942ae723; de0f3e7174ce21d2707294e450d7e5e0e820b264. Business impact: more robust LTE connectivity with native TLS contexts and lower maintenance burden. - Trusted Firmware-M integration and storage/config improvements: integrate bl_storage.c into the TF-M build; enhance storage configuration usability via Kconfig adjustments; update TF-M revision to a newer version for bug fixes and features. Commits: cdbb369b6adc8f742dca6574bd2fad5b326e830e; cb7eeac725130b0a50981bce4f65405656c4a644; 871117eee2304921673bb6288e3fde2b47bdf45c. Business impact: streamlined TF-M integration, easier storage configuration, and access to latest fixes/features. - Protected Storage API enhancement: tfm_ps_get_info now returns capacity, improving visibility into maximum storage object size without changing core logic. Commit: fafe163c21736bf454568e28510da8977215f287. Business impact: improved data management and caller usability for storage resources. Overall impact and accomplishments: - Strengthened system reliability and stability through targeted modem timeout tuning and cleanup of AT-command workarounds. - Delivered end-to-end improvements from low-level TF-M integration to higher-level storage API enhancements, enabling safer and more configurable storage usage. - Demonstrated end-to-end capabilities across two repositories with clear linkage between fixes, config usability, and feature delivery. Technologies and skills demonstrated: - Embedded C, Linux-based tooling, and build system customization. - TF-M integration and secure storage configuration (Kconfig changes). - API design and backward-compatible improvements to Protected Storage with capacity reporting. - Version control hygiene and commit discipline with traceable changes across multiple commits.

Month 2024-10: Delivered targeted security configuration work for Nordic nRF platform by propagating nRF54L15 approtect settings through TF-M and adding CMake definitions to support authenticated and secure approtect configurations. This enables finer-grained device protection and reduces risk in secure boot/TF-M integration across components.