Snowflake Implementation
End-to-end Snowflake setup: account configuration (cloud provider + region), virtual warehouse sizing and auto-suspend (right-size compute overspending is idle warehouse time), role-based access control (RBAC), network policy (IP whitelisting), Snowflake Data Sharing, cost monitoring (resource monitor budget limits, email alert at 80%).
BigQuery Implementation
BigQuery setup for GCP-native teams: project and dataset organisation (dev/staging/prod), partitioning strategy (partition pruning is primary cost control), clustering (reduce bytes scanned further), scheduled queries, BigQuery ML (train and serve ML with SQL), cost monitoring (Quotas + budget alerts).
Schema Design (Star/Medallion)
Dimensional modelling (star schema fact tables + dimension tables, standard for analytical performance) and medallion architecture (Bronze raw → Silver cleaned → Gold business-ready). Principles: appropriate grain, slowly changing dimensions (SCD Type 2), surrogate keys, naming conventions enforced via dbt contracts.
Query Optimisation & Cost Control
Query profiling (identify most expensive queries by bytes scanned/credits), partitioning and clustering (add partition filters 5-10x cost reduction), materialised views (pre-compute expensive aggregations), result caching (Snowflake caches identical queries for 24 hours), warehouse right-sizing (downsize idle warehouses, auto-suspend to 1-5 minutes).
Data Warehouse Migration
Migrate from legacy warehouses (Teradata, Netezza, Oracle, Azure SQL DW) to modern cloud: SQL translation (automated via Schema Conversion Tool, custom functions manual), data validation (compare row counts/aggregates between legacy and target), ETL/ELT migration (SSIS/Informatica → dbt + Airflow), parallel run period (validate before decommission).