OnlyCat is a fast-growing smart pet technology company building intelligent, AI-powered products for cat owners around the world.
What began as a home prototype has grown into a global brand, with thousands of smart cat flaps shipped to customers worldwide and 4x year-on-year growth. Recently recognised on BBC One’s Dragons’ Den with a major investment offer from Steven Bartlett, OnlyCat has gained strong market validation and is now entering its next stage of growth: scaling production, deepening its technology stack, and building the next generation of smart pet appliances.
Our flagship product is an advanced AI-powered cat flap with a 99.4% accurate prey detection system. It combines a high-definition night-vision camera, local machine learning, an e-paper display, dual RFID microchip scanning, cloud connectivity, and custom embedded hardware to help keep homes free from unwanted prey while giving owners genuine peace of mind.
You will join a hands-on, collaborative engineering team working across embedded software, electronics, mechanical engineering, product design, AI, and manufacturing. This is a rare opportunity to work on a real-world consumer product where your firmware directly controls physical hardware, ships to customers, and shapes the experience of thousands of users.
The Opportunity
We are looking for a talented mid-level Embedded Software Engineer to take ownership of production firmware running on OnlyCat’s custom dual-core RISC-V SoC platform.
This role is ideal for an engineer who enjoys writing clean, maintainable C++ while staying close to the hardware. You should be comfortable working under real embedded constraints: limited memory, tight timing requirements, physical peripherals, camera pipelines, networking, storage, bootloaders, and the occasional stubborn prototype that only reveals its secrets under an oscilloscope.
We actively encourage the use of modern development tools, including LLMs, to accelerate daily work. However, this is not a role for someone who treats generated code as magic. Our systems are resource-constrained and hardware-facing, so the successful candidate must understand the code at a first-principles level and be able to keep the final codebase clean, concise, stable, and maintainable.
You will have meaningful ownership from day one and will help shape the embedded architecture of a product line with global potential.
What You Will Work On
- Core Firmware Development
Develop and optimise production-grade C and C++ firmware for a dual-core, heterogeneous RISC-V SoC running FreeRTOS.
- Communication Stack
Maintain and expand firmware responsible for Wi-Fi connectivity, secure TCP/IP cloud communication, local e-paper UX rendering, SD/MMC storage, USB interfaces, and over-the-air update flows.
- Vision and Inference Pipeline
Work on high-speed camera capture, hardware-accelerated JPEG encoding, local NPU classification pipelines, and inter-core communication between processing domains.
- Low-Level Peripheral Integration
Configure, debug, and maintain interfaces including I2C, SPI, UART, USB, SD/MMC, GPIO, timers, DMA, and other SoC peripherals.
- Embedded Architecture
Design robust software abstractions suitable for constrained systems, using tools such as the Embedded Template Library to manage fixed-capacity data structures and avoid memory fragmentation.
- Hardware Debugging
Diagnose issues on real prototypes using oscilloscopes, logic analysers, serial consoles, datasheets, schematics, and careful reasoning, working closely with our lead electronics engineer and wider hardware team.
- Product Reliability
Help ensure firmware is stable, recoverable, testable, and suitable for real customers using the product every day in unpredictable home environments.
What We Are Looking For
You do not need to know every part of our stack already, but you should be a strong embedded engineer who enjoys learning quickly and solving difficult problems properly.
Essential Experience
* Strong professional experience writing embedded software in C and C++.
* A solid understanding of low-level systems, including registers, interrupts, DMA, memory mapping, timing constraints, and peripheral configuration.
* Practical experience with RTOS concepts such as tasks, queues, semaphores, mutexes, stack limits, scheduling, and resource ownership.
* A clear commitment to writing clean, readable, maintainable, and testable code.
* Comfort debugging physical hardware using tools such as oscilloscopes, logic analysers, serial consoles, and schematics.
* A genuine passion for technology, embedded systems, and building products that work in the real world.
* A collaborative, practical mindset suited to a fast-moving multidisciplinary startup.
Bonus Skills
Experience in any of the following would be valuable, but is not required:
* RISC-V architectures or custom compiler toolchains.
* The Embedded Template Library or allocation-aware C++ development.
* FreeRTOS on production devices.
* Embedded networking protocols such as TCP/IP, Wi-Fi, HTTP, MQTT, TLS, or AWS IoT.
* OTA bootloaders, secure update flows, or fail-safe firmware recovery.
* Camera sensor interfaces, image capture, ISP pipelines, JPEG/MJPEG encoding, or image processing.
* Deploying quantised machine learning models using TensorFlow Lite Micro, ONNX, or local NPUs.
* STM32, Cortex-M, ESP32, or similar microcontroller platforms.
* Consumer electronics, IoT products, or connected devices shipped to real users.
* Working in small engineering teams where software, electronics, mechanics, and manufacturing overlap.
Why Join OnlyCat?
- Build Something Real
This is not dashboard software or another abstract platform. You will write firmware that controls motors, sensors, cameras, radios, storage, displays, and machine learning pipelines inside a physical product used by real customers.
- Work Close to the Hardware
You will be based on-site with direct access to prototypes, lab equipment, mechanical engineers, electronics engineers, and product designers. Fast feedback loops matter here.
- High-Impact Engineering
As part of a small team, your work will have a visible impact on product performance, reliability, customer experience, and the future technical direction of the company.
- Modern Tools, Serious Engineering
We embrace modern development workflows, automation, and LLM-assisted productivity, while maintaining high standards for code quality, correctness, and technical ownership.
- Startup Upside
You will join at an exciting stage: early enough to make a major contribution, but with a product already in market, strong customer demand, rapid year-on-year growth, national media recognition, and clear market validation.
Benefits
* £33,000 – £60,000 salary, depending on experience.
* Tax-advantaged EMI share options.
* On-site role in a hands-on mechatronics lab.
* Direct access to hardware, prototypes, and test equipment.
* Collaborative, technically ambitious engineering culture.
* On-site parking and free parking.
* Regular company-sponsored social events.
Who This Role Suits
This role will suit someone who enjoys the craft of embedded software: understanding what the hardware is really doing, writing efficient and maintainable code, debugging with patience and precision, and seeing their work become part of a real product.
You might be the right fit if you get satisfaction from making constrained systems behave reliably, care about code quality, and want to help build a technically ambitious consumer electronics company from the inside.
How to Apply
Please send your CV, along with a short note about a firmware, embedded systems, electronics, robotics, IoT, or hardware project you have worked on and found technically interesting.
We are especially interested in candidates who can show curiosity, ownership, and a genuine enthusiasm for building technology that works in the real world.
Pay: £33,000.00-£60,000.00 per year
Benefits:
- Casual dress
- Company pension
- Free parking
- On-site parking
Work Location: In person
