data engineering , semantic modeling , Orchestration, ELT, Performance Tuning, Data Governance, Spark, Databricks, Etl, Reliability Engineering, Data Pipelines, Cost-aware Pipeline Design, Flink, GraphRAG, Metadata-driven Architectures, Compliance Controls, Observability, Big Data Architecture, Data Lakes, Lineage, Data Contracts, RAG, Ontology Design, Lakehouses, AI-serving layers, Knowledge Graphs