Analytics Engineering Overview
Apply software engineering to the data warehouse
Analytics engineering is the discipline of transforming raw data into clean, tested, documented datasets that analysts can trust. It borrows software engineering — tests, version control, code review — and applies it to the data warehouse.
What you will learn
- Describe the analyst-to-engineer data flow and where the gaps are
- Explain ELT vs ETL and why warehouses made transformations shift left
- List the practices that make a warehouse dataset trustworthy
What is this?
Analytics engineering sits between the data engineer and the analyst. Data engineers move raw data into the warehouse (ELT's 'load'); analytics engineers transform, test, and document it so analysts query a trusted semantic layer instead of raw chaos. The craft is defined by principles: transformations in code, tests on every dataset, docs at the model level, and version control end to end.
Why do you need it?
- Untested transformations make every analyst an investigator; tested models make them analysts again.
- One well-modeled dataset serves a hundred dashboards instead of a hundred copy-paste queries.
- Documentation and lineage turn a warehouse into an on-ramp for the whole team.
Mental model
Handing every analyst a pile of raw ingredients
A tested, labeled pantry
Analytics engineering is the kitchen prep — washing, measuring, labeling, and refrigerating — so the chefs (analysts) can cook instead of forage.
How it works
- Raw data lands in a warehouse staging layer as close to source as possible.
- Staging models lightly clean: type coercion, deduplication, renaming.
- Marts and intermediate models reshape data for business questions.
- Every model gets tests, docs, and lineage; the semantic layer exposes final business metrics.
Raw sources flow through staging, marts, and a tested semantic layer.
In production
- dbt defines models in SQL, runs them in the warehouse, and tests each one on every run.
- Pipeline reviews catch duplicated logic before it spreads to four dashboards.
- Data docs include lineage so a metric change is traced to its source instead of argued about.
Best practices
- Version control every model and review them like code.
- Keep staging close to source; do not mix business logic into loading steps.
- Test what changes: freshness, uniqueness, not-null, and relationship integrity.
Common mistakes
- Defining the same metric in five transformations, then watching five numbers disagree.
- Transforming directly from source tables so a logic change rewrites everything downstream.
- Documenting only the final report and losing the reasoning that produced it.
Debugging tips
- Two dashboards disagreeing is usually a duplicated-model problem — trace both to their staging parents.
- If a model 'randomly' broke, check freshness first, then upstream schema changes.
Interview checkpoint
Quick quiz
Analytics engineering is best summarized as
The most expensive mistake in analytics engineering is