Senior Ruby on Rails Developer (IoT Integrations)

About Us Welcome to the Cutting-Edge of Innovation: ZAZZ Step into the world of ZAZZ, a realm where innovative design meets software development brilliance. We're not your average tech company; we're trendsetters shaping the future, crafting digital masterpieces, and redefining boundaries. At ZAZZ, technology isn't just a tool—it's our canvas, our playground. Our passionate, ingenious team doesn't just adapt to the latest technologies; we shape them. Join us, and you’ll be at the heart of a revolution, influencing, and driving technological advancements. Empowering People. Transforming Experiences. Ever dreamed of putting your mark on the digital universe? ZAZZ is the place. We breathe life into a bottom-up approach where our employees and users are the stars. Here, you won't just be creating software—you'll be part of a grand journey to revolutionize digital experiences. Dive into the Tech Spectrum With ZAZZ, you don't just get a job; you get an open ticket to a roller-coaster of challenges and opportunities. From Product Strategy, IoT App Development to the bleeding-edge Blockchain tech, we cover the entire spectrum of tech innovation. Prepare to ignite your creativity and fuel your passion in an environment buzzing with groundbreaking ideas and projects. Shaping the Future, Together It doesn't matter if our client is a fledgling startup, a dynamic SME, or a Fortune 500 titan—we’ve partnered with them all. At ZAZZ, you'll gain unparalleled exposure and experience in diverse sectors and technologies. You’ll not just grow; you'll evolve. Why Join ZAZZ? If you're seeking a place where your curiosity is celebrated, your skills valued, and your growth accelerated, look no further. ZAZZ offers a thriving work environment, opportunities for continuous learning, and the chance to work with some of the best minds in the industry. Plus, our team loves to get geeky over a coffee chat on the latest tech! So, are you ready to leave a lasting footprint in the tech world? Join the ZAZZ family, and together, let's create the future. Job Description This is a remote position. About the Role - We are looking for a senior Rails engineer who has spent years building backends that talk to physical devices, not just browsers. - You will own backend architecture across multiple client projects, set technical direction on IoT integrations, and act as the escalation point when device-to-cloud pipelines break. Key Responsibilities - Own end-to-end architecture for Rails applications and APIs serving connected device fleets - Design and lead IoT communication layers using MQTT, WebSockets, CoAP, or HTTP-based protocols - Architect high-volume telemetry ingestion, queuing, and real-time processing pipelines - Make build-vs-buy calls on IoT platforms, message brokers, and data stores, and defend them to clients - Design schemas and scaling strategy for time-series and event-heavy workloads - Integrate cloud IoT services such as AWS IoT Core or Azure IoT Hub, including device provisioning, certificates, and OTA update flows - Lead code reviews, define engineering standards, and mentor mid-level and senior developers - Run technical discovery with clients and firmware or hardware teams, and translate that into scoped delivery plans - Diagnose production issues that cut across device, network, and application layers Required Skills - 8+ years of professional software engineering, with at least 6 years hands-on in Ruby on Rails - Proven track record of shipping and scaling IoT integrations in production - Deep experience with MQTT or equivalent device messaging protocols at scale - Strong API design skills, including versioning, contracts, and long-term maintainability - PostgreSQL or MySQL at scale, with real query and index optimization experience - Redis, Sidekiq, and distributed background job architecture - Solid testing discipline with RSpec or Minitest - Docker, CI/CD, and production deployment ownership - Experience leading a team or owning delivery on multiple concurrent projects Good to Have - Time-series databases such as InfluxDB or TimescaleDB - Kafka, RabbitMQ, or similar event streaming platforms - Exposure to edge gateways, embedded systems, or firmware collaboration - Working knowledge of Python, Go, or Node.js for device-side tooling - Infrastructure as code and cloud cost optimization on AWS or Azure - Prior agency or consulting experience with client-facing technical ownership