Our Lisbon AI projects follow EU AI Act-compliant development practices from the architecture phase. Problem definition and risk assessment (week 1): before any modelling, we define: what business problem does the AI solve? What data is available? What performance threshold makes the AI valuable? And critically: what is the EU AI Act risk classification? High-risk AI systems (credit scoring, healthcare diagnostics, employment screening) require: risk management system documentation, data governance measures, technical documentation, record-keeping, transparency and information provision, human oversight, and accuracy, robustness, and cybersecurity requirements. We assess risk classification with the client's legal team and build compliance requirements into the project plan from the start. Data engineering (weeks 2-4): Portuguese AI projects face specific data challenges. Portuguese language data: European Portuguese training data is scarce compared to English (100x less text data available). We augment with: curated European Portuguese text corpora (news, government documents, academic papers), Portuguese-specific data cleaning (handling diacritical marks, Portuguese abbreviations, Portuguese date/number formats), and transfer learning from Brazilian Portuguese models (adapting to European Portuguese vocabulary and grammatical differences). Structured data: Portuguese business data often uses Portuguese-format dates (DD/MM/YYYY), Portuguese number formatting (1.234,56 instead of 1,234.56), Portuguese addresses (without zip+4, using código postal format like 1000-001), and Portuguese business identifiers (NIF — Número de Identificação Fiscal). Our data pipelines handle these format differences correctly. Model development (weeks 3-6): selecting architectures appropriate to the problem. For Portuguese NLP: fine-tuning multilingual models (mBERT, XLM-RoBERTa) on European Portuguese data — or using Portuguese-specific models (BERTimbau — trained on Brazilian Portuguese, adapted for European Portuguese) for tasks requiring deep Portuguese language understanding. For tabular prediction (credit scoring, demand forecasting, churn prediction): gradient-boosted trees (XGBoost, LightGBM) — these consistently outperform deep learning on structured business data. For computer vision: CNN architectures (ResNet, EfficientNet) or Vision Transformers, fine-tuned on domain-specific Portuguese data (medical imaging, manufacturing quality inspection, agricultural crop monitoring). For generative AI: fine-tuned LLMs (Mistral, Llama) for European Portuguese text generation — customer support, content creation, document summarisation. Model evaluation: beyond accuracy metrics, we evaluate: fairness (does the model discriminate against protected groups? — EU AI Act requires bias assessment for high-risk systems), explainability (can individual predictions be explained? — SHAP values, attention visualisation, feature importance), robustness (how does the model handle edge cases, adversarial inputs, and data drift?), and privacy (does the model leak training data? — particularly important for GDPR compliance). Deployment and monitoring (weeks 5-8): deploying AI models as production services on EU infrastructure. Infrastructure: AWS eu-west-1 (Ireland) or eu-south-1 (Milan) — GDPR-compliant EU data residency. Model serving: FastAPI for real-time inference, Airflow for batch processing. Monitoring: tracking prediction distributions, input data quality, and model performance — alerting when model accuracy degrades (model drift). CI/CD for ML: automated retraining pipelines, A/B testing of model versions, and model versioning (MLflow for experiment tracking and model registry). EU AI Act documentation: for high-risk systems, we prepare: technical documentation (model architecture, training data, performance metrics, limitation analysis), risk management documentation (identified risks, mitigation measures, residual risk assessment), and human oversight specification (how humans monitor and override AI decisions).