IoT Systems & Hardware Integration Engineer

About the Job

Apollo is one of the fastest-growing AI-powered ClimateTech SaaS companies, building the next-generation Sustainability Intelligence Platform (SIP). Our mission is to help enterprises measure, understand, and reduce their energy consumption and carbon footprint — transforming sustainability from a reporting obligation into a strategic decision engine that drives real business and environmental impact.

To date, Apollo has helped organizations achieve the equivalent of reducing more than 220,000 tons of carbon emissions and creating an environmental impact comparable to planting over 10 million trees. Through AI-powered insights, benchmarking, and actionable intelligence, we enable leading enterprises to improve operational efficiency while accelerating their decarbonization journey.

We're looking for an engineer who will build our hardware-agnostic IoT network from the ground up, ensuring that data flowing from the physical world into our platform is continuous, reliable, and scalable. This role combines a software engineer who writes asynchronous backend services at a desk with a systems engineer who configures modems and meters in the field.

The system you build will rely on an event-driven architecture in which thousands of field-deployed edge devices continuously push data to a central server. It will start with the modem brands/models and limited set of protocols you select, but thanks to its hardware- and protocol-agnostic, flexible design, you will build an edge-to-cloud data collection and processing infrastructure that can scale to 10,000 modems and 50,000 edge devices.

You will design this architecture from scratch and bring it to life end-to-end — from broker and database selection, to backend services, the payload parsing layer, and the remote device management panel. You will decide on the technology stack (backend language, frameworks, tools); what matters to us isn't the language you use, but that you build a scalable, reliable, and sustainable system.

What You'll Do

As an IoT Systems & Hardware Integration Engineer, you will design and build Apollo's edge-to-cloud IoT infrastructure end-to-end — from architecture and hardware selection to backend services and remote device management.

Your responsibilities will include:

Architecture & Setup

• Evaluating managed services such as AWS IoT Core, EMQX Cloud, and HiveMQ against open-source solutions (EMQX, Mosquitto) in terms of cost, scalability, and data control, and deciding on the MQTT broker infrastructure.

• Designing a time-series database infrastructure suited to a 50,000-device scale (PostgreSQL/TimescaleDB or InfluxDB).

• Building a secure, highly available infrastructure with VPCs, subnets, load balancers, and strict firewall rules.

Hardware & Protocol Management

• Evaluating and selecting the industrial modem/gateway hardware best suited to the system's initial needs. The hardware choice is yours, but the criterion is a brand that is globally widespread, easy to find technical support and sales partners for, works seamlessly across different bandwidths, and can be sourced "zero-friction" anywhere in the world (e.g., Teltonika, Robustel; Schneider, Siemens, etc. may also be considered if suitable).

• Designing the system with the flexibility to work with different brands in the future, without locking it to a single brand/model beyond the hardware initially chosen.

• Reading data from electricity meters, energy analyzers, water/gas flow meters, and environmental sensors using industrial and metering communication protocols such as Modbus RTU/TCP, OPC-UA, M-Bus, DLMS/COSEM, and IEC 62056-21.

• Not just reading data but also writing to devices: updating configurations, setting alarm thresholds, and performing remote relay/output control (e.g., Modbus write). Designing a secure, authorized, and auditable command flow for these operations, which have physical consequences.

• Configuring the industrial gateways you select: Modbus Master settings, RS-485/Ethernet communication parameters (baud rate, parity), and MQTT topic templates.

• Building a standard data dictionary by resolving meters' register addresses, data types, and byte ordering (endianness).

Software & Integration

• Building a high-performance MQTT Consumer service capable of handling thousands of messages per second, preventing CPU bottlenecks using methods suited to your chosen tech stack (asynchronous processing, clustering, etc.).

• Writing a modular, testable payload parsing layer that converts raw hexadecimal/binary data from modems into meaningful, structured JSON.

• Writing data to the time-series database with connection pooling and batch insert optimizations; building robust error handling with store-and-forward, dead-letter queues, and auto-recovery.

• Designing and building the remote management panel where device health is monitored and configuration/OTA updates can be sent.

• Developing additional services beyond the edge-to-cloud flow based on future customer needs — for example, a flexible architecture that can support classic centralized polling scenarios where meters are connected directly via TCP/IP through a transparent modem.

Scalability & Security

• Running end-to-end load and stress tests at the scale of 10,000 modems / 50,000 devices; measuring throughput and resource limits to determine scaling needs (e.g., whether to add a message queue layer such as SQS or Kafka between the broker and the database).

• Building a security model in which every device is authenticated with a unique identity and traffic is encrypted end-to-end (e.g., device-based certificates / mTLS), preventing unauthorized devices from pushing data into the system.

• Providing secure access for isolation between IT and OT networks and for remote troubleshooting/debugging via encrypted tunnels such as WireGuard/OpenVPN.

Partner Management & Technical Support

• Establishing partnership agreements with hardware suppliers and installation teams across different countries and regions, and managing proposal processes and SLA standards.

• Preparing user guides, training materials, and SOPs for partners and customers.

• Designing the appropriate hardware topology for customers; providing technical support in pre-sales and post-sales processes.

What We're Looking For

We are looking for someone with hands-on experience designing and deploying industrial IoT systems who can take ownership of this architecture end-to-end.

You might be a good fit if you:

• Have a Bachelor's degree in Computer Engineering, Electrical-Electronics Engineering, or a related field.

• Have proven experience designing and deploying end-to-end (edge-to-cloud) industrial IoT (IIoT) architectures.

• Have deep technical knowledge of industrial and metering communication protocols (Modbus RTU/TCP, OPC-UA, M-Bus, DLMS/COSEM, IEC 62056-21, BACnet, etc.) and SCADA integration.

• Are proficient in network communication protocols such as MQTT, TCP/IP, RESTful APIs, and WebSockets.

• Have experience building high-performance, asynchronous services and data parsing algorithms in a backend language/stack of your choice — you'll have the freedom to choose the tech stack in this role.

• Have experience designing and modeling data for time-series databases (PostgreSQL/TimescaleDB, InfluxDB).

• Have hands-on knowledge of cellular network configurations (LTE, M2M SIM, APN), firewall management, and VPNs (OpenVPN, WireGuard).

• Have experience evaluating, configuring, and deploying industrial IoT gateway/modem devices (e.g., Teltonika, Robustel, or equivalents) in the field.

• Have advanced written and verbal English (required for global partner, supplier, and customer conversations).

Nice to Have

These are not required, but would be considered a strong advantage:

• Experience with high-volume data streaming using Kafka or similar message queue systems.

• Experience building OTA update and remote device management infrastructure.

Familiarity with Docker, CI/CD, and observability tools