Edge & Machine Integration Engineer (PLC to Cloud), Freelance, m/f/d

ppFALU AG in Rüti (ZH) builds and sells swab production machines that run in plants around the world. With FALU PMAS, our cloud based production monitoring and assistance system, every machine reports its state every five seconds. Customers get live dashboards, shift KPIs, downtime analytics and automatic alerts in the browser. The first customer went live in September 2026 with eight machines, and more plants are lined up. /p pThe cloud side of PMAS is built and running in production: broker, ingestion service, databases, web app. The path from the PLC inside the machine to the MQTT broker is covered by one engineer who designed and built it. With more machines and more plants coming, that one person is no longer enough. We are looking for a freelancer who adds capacity on exactly this path: PLC software, Raspberry Pi edge devices, site gateway, broker connection. /p pThis is a permanent role that we staff on a freelance basis: no project end date, a long term engagement with about 1 week of work per month, with more when a rollout is on. You will work directly with our existing integration engineer, our inhouse engineering team and the CEO. /p h3Tasks /h3 pYou work on everything between the machine PLC and the MQTT broker, alongside the engineer who built the current setup. Which parts you take over completely and which you share depends on your strengths. Concretely: /p pbPLC and machine side /b /p ul liBring the PMAS message format into the CB1 machine software (Siemens S7, TIA Portal V18 with HMI) and keep it in sync with the payload contract: cumulative counters, machine status, error codes, timestamps from the PLC clock. /li liDecide and implement how data leaves the PLC: MQTT publishing from the PLC itself, or a read on the edge device (S7 protocol or OPC UA) that publishes on its behalf. Pick one, justify it, standardise it. /li liManage PLC software versions across the fleet, including safe update and rollback procedures for machines already running at customers. /li liEnsure clock discipline on the PLCs (NTP, local time zone per plant), since every duration KPI is computed from PLC timestamps. /li /ul pbEdge devices and site gateway /b /p ul liDevelop and maintain the software on the Raspberry Pi based edge devices next to each machine: MQTT client, buffering and store and forward during uplink outages, unique client IDs, credential handling, health reporting. /li liDevelop and maintain the site gateway: isolated machine network, routing and firewall, outbound only TLS and NTP, remote maintenance access, watchdogs, recovery from a spare device. /li liHelp turn the current setup into a provisioning process: golden image, per machine configuration, fleet wide updates without a site visit. A new machine goes from unboxing to "visible in the dashboard" in under an hour. /li liMonitor the edge layer so that we know about a degraded device before the customer does. /li /ul pbBroker and data contract /b /p ul liAdminister the HiveMQ Cloud clusters per customer: credentials, topic ACLs, client ID scheme, certificates. /li liMaintain the payload contract together with the existing integration engineer. Changes are versioned and documented. /li /ul pbCommissioning and support /b /p ul liOnboard new customers and new machines end to end, remotely where possible and on site where needed (primarily Europe and the United States). /li liAct as second line when "the dashboard shows nothing" or "the numbers look wrong" and the cause sits between PLC and broker. /li liWrite the documentation you would have wanted on day one: onboarding sheets, runbooks, wiring notes. /li /ul h3Requirements /h3 pbMust have /b /p ul liSiemens PLC programming in TIA Portal (SCL and LAD, S7-1200/1500 family). You can open an existing machine project, understand it and change it without breaking the machine. /li liIndustrial networking: PROFINET, VLANs, static and DHCP setups, firewalls, TLS basics. You have connected a machine to a network that was not built for it. /li liLinux on Raspberry Pi or comparable single board computers: systemd, networking, images, headless operation, remote administration. /li liSolid programming skills in Python or Node.js for edge software, and Git as a daily tool. /li liMQTT in depth: versions 3.1.1 and 5.0, QoS levels, retained messages, last will, TLS, broker ACLs. /li liProficiency with AI coding tools is a hard requirement. You use Claude Code, Cursor, Copilot or comparable tools every day, you write and maintain project instructions for them, you review their output critically, and you are measurably faster with them than without. Our code and documentation are written with and for these tools. If you see AI tools as optional, this role is not for you. /li liWorking proficiency in English (all code, commits and documentation are in English). German is a plus for the machine side. /li liWillingness to travel to customer plants, typically a few days per quarter. /li liAvailability of at least two days per week on a permanent basis, with the option to scale up during rollouts. /li liYou work as a freelancer (own company or registered self employed) and can invoice FALU AG. /li /ul pbNice to have /b /p ul liOPC UA, Snap7 or the Siemens open communication libraries. /li liNode-RED, Docker on ARM, Ansible or similar fleet tooling. /li liMachine building or commissioning experience: reading electrical schematics, 24 V control cabinet basics, HMI (WinCC). /li liAdministration of HiveMQ, Mosquitto or EMQX. /li liA basic understanding of what happens after the broker (Node.js services, PostgreSQL, ClickHouse), so that you can talk to the cloud side at eye level. /li /ul h3Benefits /h3 ul liA clearly bounded, business critical scope with a colleague who knows the system and hands over properly. No cold start. /li liA running production system with a real customer, not a greenfield slide deck. /li liAI assisted development is how we work, not an experiment. You get the tools and the budget for them. /li liMachines you can touch: a test bench at FALU in Rüti with real PLCs and edge hardware. /li liRemote by default, on site in Rüti when hardware is involved. Travel to customer plants is paid on top of the rate. /li liA permanent role, not a project with an end date: growing volume as more plants go live, on a freelance basis for as long as it works for both sides. /li liFast, uncomplicated invoicing and decisions from a small team. /li /ul /p #J-18808-Ljbffr