# SQL > Selected Engineer ApS work demonstrating SQL — the achievements that prove it. - [Engineered hourly electricity consumption aggregation pipeline in Python / SQL / Bash + Jq, achieving 180ms for 30‑day datasets across heterogeneous JSONL sources.](https://engineer.company/portfolio/engineered-hourly-electricity-consumption-aggregation-pipeline-in-python-4/) - [Accelerated geographical data pipeline performance by 50x by improving SQL programming and data modeling across PostgreSQL, MS SQL, and Google Cloud BigQuery.](https://engineer.company/portfolio/accelerated-geographical-data-pipeline-performance-by-50x-by-5/) - [Improved geographical map application performance by 10x through strategic database transition from MSSQL to PostgreSQL, optimizing processing and data security.](https://engineer.company/portfolio/improved-geographical-map-application-performance-by-10x-through-6/) - [Resolved 1,000 issues in geographical data and time‑series data, using GDAL, ArcGIS, PostGIS, Mapbox, QGIS, SQL (PL/pgSQL, Transact‑SQL), Bash, ensuring high‑quality big data processing.](https://engineer.company/portfolio/resolved-1-000-issues-in-geographical-data-and-7/) - [Designed, implemented, and administered 6 ETL/ELT pipelines, utilizing Google BigQuery, MSSQL, PostgreSQL, Shell scripting, PL/pgSQL, and Transact‑SQL, integrating data for efficient Python API processing.](https://engineer.company/portfolio/designed-implemented-and-administered-6-etl-elt-pipelines-8/) - [Released 500 electricity and GIS data analysis reports, utilizing deep research and troubleshooting to ensure accurate geographic and time series big data insights.](https://engineer.company/portfolio/released-500-electricity-and-gis-data-analysis-reports-11/) - [Architected, created, and managed 100 PostgreSQL, MS SQL, and Google BigQuery data warehouse databases with primarily GIS and time‑series data, optimizing performance and scalability.](https://engineer.company/portfolio/architected-created-and-managed-100-postgresql-ms-sql-12/) - [Accelerated PostgreSQL performance by 10x via strategic indexing, partitioning, and query optimization, enhancing database efficiency for user, tenant, geospatial, and time‑series electrical data.](https://engineer.company/portfolio/accelerated-postgresql-performance-by-10x-via-strategic-indexing-15/) - [Automated GIS SaaS application deployment, data processing, and reporting system using GitHub Actions CI/CD, Python, Bash, and SQL.](https://engineer.company/portfolio/automated-gis-saas-application-deployment-data-processing-and-16/) - [Led the development, deployment, and support of over 30 GIS projects, demonstrating expertise in PostgreSQL, Bash, Python, JavaScript, GDAL, ArcGIS, PostGIS, and Mapbox technologies.](https://engineer.company/portfolio/led-the-development-deployment-and-support-of-over-35/) - [Automated data processing tasks using Shell scripting, PL/pgSQL, Python, and Transact‑SQL, increasing productivity and efficiency.](https://engineer.company/portfolio/automated-data-processing-tasks-using-shell-scripting-pl-45/) - [Engineered 600 PL/pgSQL‑based ETL/ELT pipelines to streamline complex data processing workflows across multiple PostgreSQL development and production environments.](https://engineer.company/portfolio/engineered-600-pl-pgsql-based-etl-elt-pipelines-54/) - [Designed a JSON passthrough architecture where PostgreSQL functions return complete JSON forwarded verbatim by the Go API, eliminating intermediate unmarshalling and decoupling the frontend from schema changes.](https://engineer.company/portfolio/designed-a-json-passthrough-architecture-where-postgresql-functions-58/) - [Designed a PostgreSQL function‑first data layer — 1,275 stored functions across 34 schemas — so every read and write goes through a function the database can grant, rather than through a table.](https://engineer.company/portfolio/designed-a-postgresql-function-first-data-layer-across-63/) - [Modeled the maritime domain into 348 normalized tables across 34 PostgreSQL schemas — professionals, companies, ships, jobs, reviews and the rest — with SMALLINT lookups and UUID v7 keys.](https://engineer.company/portfolio/modeled-the-maritime-domain-professionals-companies-ships-jobs-67/) - [Built first‑party product analytics in PostgreSQL — 47 functions over partitioned event tables that prune themselves — pseudonymised behind a rotating salt and gated on the visitor's consent.](https://engineer.company/portfolio/built-first-party-product-analytics-in-postgresql-101/) - [Built the loyalty and reputation system — 67 functions over a 31‑table ledger, with leagues, badges and a redemption shop — taking a row lock on the balance to close the double‑spend window.](https://engineer.company/portfolio/built-the-loyalty-and-reputation-system-105/) - [Generated 495 achievement pages across three languages from a read‑only SQLite export, with the page address authored as data so that correcting a sentence no longer moved the page and broke the link.](https://engineer.company/portfolio/generated-321-achievement-pages-from-a-sqlite-export-132/) - [Built a database‑driven CV, references, portfolio and cover‑letter generator in Python — 41 modules, 10,580 lines — rendering six output formats from one 23‑table SQLite source assembled by a 19‑step idempotent pipeline.](https://engineer.company/portfolio/built-a-database-driven-cv-and-portfolio-generator-144/)