Senior IoT Engineer (m/f)

Dive deeper. Aim higher.

Abysalto is a Croatian deep-tech company developing the next-generation Smart Energy Management System (SEMS) – a modular cloud platform that combines real-time IoT data, edge intelligence, and cloud analytics to optimize energy use across buildings, infrastructure, and industrial facilities. By integrating smart sensors, predictive algorithms, and ESG-ready reporting, SEMS helps organizations reduce consumption, lower CO₂ emissions, and take control of their sustainability performance – from device to dashboard.

You will join a multidisciplinary team of 15 engineers (software, energy, data science) and help create a global product. We are looking for a Senior IoT Engineer to take a leading role in the design and integration of the edge and sensor layer of the system.

Why is this an opportunity you don't want to miss?

• IoT in energy is one of the fastest growing technological areas – the global market is expanding at double-digit rates every year.
• You will work end-to-end - from the firmware on the sensor to the cloud, with a direct impact on the architecture of the entire solution.
• You will have the freedom to suggest technologies, tools and approaches, as well as the opportunity to mentor younger colleagues.
• You'll see the results of your work in real-time – every saving the platform makes is a visible trace of your code.

What you will do? 

• Firmware Development - Design, develop, and maintain firmware for ESP32, ARM -based microcontrollers, and other embedded platforms.
• Sensor Integration - Integrate and support a wide range of sensors, including those for electricity metering, temperature, humidity, CO₂, VOC, pressure, flow, vibration, and ultrasound.
• Edge Intelligence - Implement local data processing (aggregation, filtering, normalization) and ensure seamless connectivity with cloud platforms (Azure, Google Cloud etc).
• Communication Protocols & Security - Develop and optimize communication interfaces and protocols ( MQTT, LoRaWAN, Modbus RTU/TCP, BLE ), with a strong focus on secure data transmission (TLS, device authentication, OTA updates).
• Cross-Functional Collaboration - work closely with backend and data science teams to define real-time data models, API specifications, and support analytics workflows.
• Quality & Best Practices - Write clean, efficient, and testable code; actively participate in code reviews, daily stand-ups, and sprint planning.
• Technical Leadership - Contribute to architecture decisions, document designs and implementations, and mentor junior engineers within the team.
• Problem Solving & Ownership - Troubleshoot complex issues across hardware/software boundaries and take end-to-end ownership of your solutions – from concept to deployment.

What we expect from you?

• 5+ years of hands-on experience in embedded or IoT systems development, including C/C++ and real-time operating systems (FreeRTOS, Zephyr, or equivalents)
• Strong familiarity with the ESP32 ecosystem and at least one LPWAN technology (e.g., LoRa, NB-IoT, Sigfox)
• Experience working with a variety of sensor and communication interfaces such as I²C, SPI, UART, RS-485, ADC, and both analog and digital I/Os
• Solid understanding of energy-efficient embedded design : low-voltage hardware, sleep/wake cycles, and power consumption measurement
• Experience with CI/CD pipelines, OTA firmware updates, and automated testing in embedded environments
• Familiarity with at least one cloud IoT platform (e.g., Azure IoT Hub, Google Cloud IoT, AWS IoT) and time-series databases
• Ability to understand the big picture and contribute to system architecture, with a proven track record of bringing IoT products to production
• Comfortable working in agile (SCRUM) teams; experience mentoring others and contributing to team processes and best practices
• Fluent in written and spoken English, especially in the context of technical documentation and collaboration
• Ownership of end-to-end embedded product delivery, contributions to open-source projects, or experience with hardware design/debugging

Nice to have

• Experience in energy or building automation projects (e.g., BMS/EMS, ISO 50001)
• Familiarity with alternative embedded environments such as Arduino, Rust, or Go
• Ownership of end-to-end embedded product delivery
• Contributions to open-source projects or experience with hardware debugging
• Certificates: Azure IoT Developer, Cisco IoT, AWS IoT, Scrum Master or similar

What we offer?

• Work in an experienced and encouraging team
• Continuous professional development through training and conferences
• Flexible working hours with the option of hybrid work
• Be part of a green tech mission that delivers real, measurable impact on the environment and local communities.
• Access to the latest development hardware – dev kits, logic analyzers, RF tools – with the freedom to choose your preferred tools and workflow
• Full-time employment with a competitive salary, transparent bonus structure, and long-term growth opportunities
• Work in an agile environment following SCRUM methodology
• Pleasant and relaxed work environment with various perks (top-quality Herman Miller Aeron chairs, high-end equipment, discounts with partner companies)
• All perks and benefits can be found on our career page

We solve complex technological challenges in order to simplify and improve everyday lives of millions of people. Our goal is to become a leader in the software industry, recognized for excellence and quality.

If you're ready to shape what’s yet to come — send us your CV and a brief  project portfolio (GitHub, presentation, or short description).

Apply via the link below. 

We look forward to meeting you!