Looker: guardrails built by engineers
Sigma users meet Looker as a more structured experience. LookML, written by analytics engineers and stored in Git, decides which fields exist, how they join, and how each measure is computed. A business user in an Explore picks from that menu rather than writing formulas, which keeps a metric like net revenue identical across every dashboard, API call, and embedded view.
That structure has a price in flexibility. Anything not modeled has to wait for an engineer, and people used to spreadsheets can find dimension-and-measure Explores less intuitive than a grid. Looker pays off when a large audience must read the same numbers and there is engineering capacity to keep the model current.