Embedded firmware development company for an industrial IoT device (ARM Cortex-M, RTOS)

We are an industrial technology company developing a new IoT sensor device. The hardware (a custom PCB built around an ARM Cortex-M class microcontroller) is designed and frozen. We now need an experienced firmware team to take a detailed written specification and deliver production-ready firmware, from bring-up through to acceptance testing. We have a complete engineering specification ready to share with shortlisted vendors under NDA. Scope of work • MCU and board bring-up on the existing custom hardware. • RTOS-based multi-task firmware architecture. • High-rate multi-channel sensor acquisition over SPI with DMA. • On-device digital signal processing (windowed FFT) with reference-vector validation. • One on-device protection/threshold function with deterministic timing. • External flash management for event-data buffering. • Secure cloud telemetry: MQTT over TLS with a hardware secure element; binary payload encoding; HTTPS upload path. • Documentation, unit and integration tests, and a factory flashing / first-article procedure. Required skills and experience • Embedded C on ARM Cortex-M microcontrollers. • RTOS (e.g. FreeRTOS) task design, DMA, interrupt-driven acquisition. • CMSIS-DSP or equivalent signal processing on MCU. • TLS/MQTT on embedded, and hardware secure elements / cryptography. • MISRA C or comparable safety-critical coding discipline. • Demonstrable production embedded projects (please share references). • Git-based workflow, code review, and continuous integration. Engagement • Fixed, well-defined specification; we expect a phased plan with milestone-based acceptance. • NDA required before the specification is shared. • Private Git repository, commits from day one. • Named point of contact and a weekly review call. Preferred location Czech Republic preferred; USA and India also welcome. How to apply Please include: 1. A short introduction to your company (size, location, years in embedded). 2. Two or three relevant projects (ARM Cortex-M / RTOS / secure IoT). 3. Your typical engagement model and how you handle fixed-scope delivery. 4. Confirmation you can sign an NDA before we share details.