Full Stack Engineer

About us

Smart Energy Lab (SEL) builds the software behind the energy transition. Our platform connects, monitors and controls a wide range of distributed energy assets, including solar PV inverters, battery energy storage systems, EV chargers, smart meters, energy controllers and IoT sensors. It turns their data into smarter, cleaner energy decisions for our customers. Today it monitors a large and growing fleet of connected devices through an event-driven microservice architecture on AWS.

We're looking for a Fullstack Software Engineer to join our software engineering team.

What you'll do

Working from our Porto office in a hybrid setup, you'll design, build and run features end to end. That covers everything from the user interface down to the APIs, event streams, data and device software behind it. You will:

• Design, build, test, release and maintain features across the stack. This includes responsive, accessible web interfaces and the backend microservices and APIs that power them.

• Develop and maintain containerised Python microservices that expose secure REST APIs and consume or publish events on Kafka.

• Build real-time user experiences using WebSockets, such as:

– live energy and telemetry dashboards

– battery and solar performance views

– charging-session monitoring

– device status updates

• Work with time-series and transactional data in PostgreSQL/TimescaleDB, with an eye on query performance at scale.

• Integrate with energy assets and third-party systems over protocols such as MQTT, OCPP (WebSocket), Modbus and vendor APIs.

• Contribute to the firmware and edge software running on our controllers and gateways, using C/C++ and Bash, including support for secure over-the-air updates.

• Turn Figma designs and prototypes into clean, reusable, well-tested UI components.

• Help build AI-powered features, such as LLM-based assistants, retrieval-augmented generation (RAG) and intelligent energy analytics, using services like AWS Bedrock.

• Own what you ship (“you build it, you run it”). That means monitoring, troubleshooting and improving services in production using CloudWatch, Prometheus/Grafana and Sentry.

• Contribute to CI/CD pipelines, automated testing and secure-by-design practices aligned with ISO 27001.

• Collaborate in an agile, cross-functional team, and share knowledge through code reviews, pair programming and documentation.

What we're looking for

Must Have

• 3+ years of professional experience building web applications across front end and back end.

• Strong Python skills, with experience in FastAPI, Django or Flask and in designing RESTful APIs.

• Solid experience with a modern component-based framework (Vue.js preferred; React welcome), TypeScript/modern JavaScript, HTML5 and CSS (SASS, a UI library such as Vuetify, Material or Tailwind).

• Working knowledge of C/C++ and Bash scripting, and comfort working in a Linux environment.

• Experience with SQL databases (PostgreSQL preferred) and data modelling.

• Familiarity with microservice and event-driven architectures, and with message brokers such as Kafka, RabbitMQ or Redis.

• Hands-on experience with Docker and Git-based workflows (pull requests, code review, CI/CD).

• A habit of writing automated tests, both unit and integration (e.g. pytest, Vitest/Jest).

• Practical, responsible use of AI-assisted development tools (e.g. Claude Code, GitHub Copilot, Cursor) to work faster without compromising quality, security or code ownership.

• Fluent written and spoken English.

Nice to have

• Experience with embedded Linux, firmware development, cross-compilation or over-the-air (OTA) update mechanisms.

• Experience with AWS: EC2/Auto Scaling, ALB, S3, CloudFront, Lambda, Cognito, IoT Core, WAF or Bedrock.

• Experience building LLM-powered features: prompt design, RAG, vector search (e.g. pgvector), evaluation.

• Experience with TimescaleDB or other time-series data at scale.

• Knowledge of energy and IoT protocols such as MQTT, Modbus, OCPP or OCPI.

• Domain experience in solar PV, battery storage, EV charging, smart metering or energy flexibility markets.

• End-to-end testing with Playwright or Cypress.

• Observability tooling (Prometheus, Grafana, Sentry) and infrastructure as code.

• Familiarity with security best practices (OWASP, authentication/authorisation, encryption).

• European Portuguese is a plus.

• A portfolio, GitHub profile or links to live projects you've built. No special document is needed; just include links in your CV.

How we work

• An innovative mindset, and real alignment with our mission to accelerate the energy transition.

• A focus on measurable impact for end users, customers and the planet.

• Curiosity about emerging technologies, including AI, and the judgement to know when they add value.

• A respectful, transparent and collaborative environment where ownership and learning are encouraged.

Pratical details

• On-site presence at our Porto office at least once a week.

• Occasional meetings at our Lisbon office.

• Candidates must have Portuguese tax residency and live in mainland Portugal.