Brumbaal is a Copenhagen-based defense-tech startup developing fiber-optic communication hardware for military drones. Our systems replace vulnerable radio links with jam-proof fiber-optic connections, enabling drones to operate reliably in electronically contested environments.

We are a small, focused team. We build real hardware, test it in real conditions, and ship it to real users. If you are looking for a corporate environment with layers of process, this is not the right place. If you want to design and build communications electronics that go into production and get used in the field, keep reading.

The role

We are looking for an experienced embedded engineer with a strong background in communications and data-link design to lead the development of our proprietary electro-optical transceiver. This is a well-defined project with a clear scope: design, prototype, and bring to production a compact transceiver module that converts drone telemetry and video streams to and from fiber-optic signals.

You will work at OSI layers 3 and 4, handling packet framing, transport, error correction, and protocol bridging between standard drone control protocols (MAVLink, MSP, CRSF) and our fiber link. The role spans firmware architecture through to PCB bring-up and integration testing.

This is not a supporting role. You will be the technical lead on embedded communications, working alongside experienced hardware designers covering analog front-end, power, and mechanical integration. You own the firmware, the protocol stack, and the path from prototype to a manufacturable product.

What you will do

Work with microcontrollers (STM32 or similar ARM Cortex-M) to implement real-time data transport over fiber-optic links. Design and implement packet framing, multiplexing, and error handling for combined video and telemetry streams. Bridge standard drone communication protocols to our fiber transport layer. Bring up and debug custom PCBs, working closely with the hardware design team. Define test protocols and validation procedures for communications performance (latency, throughput, bit error rate). Take the design from working prototype through to a production-ready, manufacturable module.

What you bring

Significant professional experience in embedded systems development, specifically in communications or data-link applications. Strong working knowledge of MCU-based systems including bare-metal and RTOS firmware development. Hands-on experience with OSI layer 3/4 work: packet framing, transport protocols, error correction, flow control. Experience with high-speed serial interfaces (SPI, UART, Ethernet MAC/PHY) and ideally exposure to fiber-optic transceivers or SFP modules. Ability to read schematics, use an oscilloscope and logic analyzer, and debug at the hardware-firmware boundary. Familiarity with at least one drone communication protocol (MAVLink, MSP, CRSF) is a strong plus but not required. Experience taking a design from prototype to production, including DFM considerations and working with contract manufacturers.

What would set you apart

Prior work in defense, aerospace, or safety-critical embedded systems. Knowledge of video encoding/streaming over constrained links.

Compensation and structure

This is an equity-based position. We are a pre-revenue startup building critical defense hardware with strong market positioning and active investor interest. We are offering a meaningful equity stake to the right person because this role is foundational to the company. You would be joining as a technical co-builder, not an employee filling a slot.

We expect you to bring substantial experience and skill, and we will compensate that with ownership in a company operating in a market with clear and growing demand. Specific equity terms will be discussed directly with candidates who reach the final stage.

If you need a salary from day one, this is probably not the right fit right now. If you want to own a piece of something real in a sector that is growing fast, we should talk.