Technical proficiency
Check fluency with PostGIS, GDAL/OGR, GeoPandas or Apache Sedona, plus projection handling: EPSG codes, datum shifts, and reprojecting national grids without silent geometry corruption.
Evidence to listen for
- Command of the languages, frameworks, and data tools the role actually uses
- Understands correctness, performance, and failure modes, not just syntax
- Has opinions on testing and can justify them
- Reads and reasons about code they did not write
Five-point scoring guide
Cannot work independently; fundamentals are missing.
Weak fundamentals; output needs heavy review.
Competent for the role; needs guidance on complex or unfamiliar work.
Strong practitioner; handles hard problems with little guidance.
Names specific spatial SQL functions, tiling schemes and CRS pitfalls they have hit, and explains fixes in concrete technical terms.