# Python > Selected Engineer ApS work demonstrating Python — 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/) - [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/) - [Delivered 8 Power BI projects with comprehensive manuals, integrating Microsoft Power BI tools with NodeJS API and Python FastAPI for effective data analytics and visualization.](https://engineer.company/portfolio/delivered-8-power-bi-projects-with-comprehensive-manuals-10/) - [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/) - [Automated 100 critical data backups using Barman, Google Cloud, Bash, and Python, ensuring data integrity across databases.](https://engineer.company/portfolio/automated-100-critical-data-backups-using-barman-google-18/) - [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/) - [Streamlined data analysis and software development processes, saving 4,000 hours by introducing GitHub, GitLab, Bash, and Python CI/CD practices.](https://engineer.company/portfolio/streamlined-data-analysis-and-software-development-processes-saving-43/) - [Developed a Data Analytics reporting system, increasing quarterly software revenue by 400% through Python‑based PDF reports.](https://engineer.company/portfolio/developed-a-data-analytics-reporting-system-increasing-quarterly-44/) - [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/) - [Developed 100 web applications using HTML/HTML5, CSS/SCSS, Django, WordPress, and Joomla frameworks, ensuring diverse online presence.](https://engineer.company/portfolio/developed-100-web-applications-using-html-html5-css-51/) - [Built the Python vessel‑data scrapers (MarineTraffic, Maritime‑Database) and a repeatable import that seeds the platform's reference data — 184,197 rows, including 698 companies and 56,149 vessels.](https://engineer.company/portfolio/built-a-python-vessel-data-scraper-marinetraffic-maritime-66/) - [Developed and maintained Django web applications for the IPTV platform, shipping new features and improving performance and stability.](https://engineer.company/portfolio/developed-and-maintained-django-web-applications-for-the-84/) - [Reconciled a 20‑record DNS zone declaratively against the Cloudflare API with separate audit and BIND‑export entry points, and turned the CDN proxy back off on privacy grounds after building it.](https://engineer.company/portfolio/reconciled-a-dns-zone-declaratively-118/) - [Automated the provisioning of a second server on a second cloud provider, creating the firewall before the machine so it is born behind one, with both providers' firewalls written directly against their REST APIs to avoid a third‑party collection.](https://engineer.company/portfolio/provisioned-a-second-server-from-code-123/) - [Built a commit gate of 22 one‑line linters plus four that earn a paragraph, with no warning tier and no inline suppressions permitted, covering HTML, CSS, JavaScript, Python, YAML, Markdown, shell, links, spelling, secrets and typography.](https://engineer.company/portfolio/built-a-22-linter-commit-gate-127/) - [Cut the site's browser‑driven quality gate from 1,636 seconds to 615 by scheduling its checks longest‑first through a worker pool bounded to four lanes, after measuring that alphabetical order cost 320 seconds against 224.](https://engineer.company/portfolio/cut-the-visual-quality-gate-to-ten-minutes-128/) - [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/) - [Fixed a sitemap where 172 of 176 URLs shared one modification timestamp, by taking the date from git history after establishing that the export rewrites every file on every run.](https://engineer.company/portfolio/fixed-a-sitemap-with-one-shared-timestamp-140/) - [Put the documentation under its own linter — a per‑file line budget that only ratchets down, an index requirement and a real‑path check — which found six of nine plans marked done while carrying unchecked boxes, and fourteen commit‑gating tasks named in no document.](https://engineer.company/portfolio/put-the-documentation-under-its-own-linter-142/) - [Brought 10,242 lines of quality‑gate JavaScript under a formatter and a linter after establishing it was the largest body of code in the repository and the only one nothing read, fixing 13 findings and suppressing none.](https://engineer.company/portfolio/brought-the-quality-gate-code-under-a-linter-143/) - [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/) - [Held the generator to 981 test cases at a 92% branch‑coverage floor with warnings treated as failures, and asserted idempotence by running the whole build pipeline twice from an empty file and requiring the second pass to change nothing.](https://engineer.company/portfolio/held-the-generator-to-964-tests-and-a-coverage-floor-145/) - [Established PDF/UA‑1 conformance across nine documents at 106 of 106 rules, and found the archival variant failing one rule of 146 — a near‑miss that reads as a pass to anyone not running the validator.](https://engineer.company/portfolio/established-pdf-ua-1-conformance-across-nine-documents-146/) - [Selected every rule the Python linter has as an error, working through 1,815 findings to reach zero, with each of the few exemptions carrying a written reason and two of them backed by a checker instead of a comment.](https://engineer.company/portfolio/enabled-every-python-linter-rule-as-an-error-147/) - [Vendored a QR encoder — Reed‑Solomon over GF(256), fixed module layout, eight mask patterns — in 522 lines rather than take a third runtime dependency, and verified it by reading the finished matrix back with an independently written decoder.](https://engineer.company/portfolio/vendored-a-qr-encoder-in-522-lines-148/) - [Wrote tests for the checkers themselves after establishing that a checker fed only clean input will one day report clean because it read nothing — planting a misspelling to confirm the spell‑check finds it, and taking an id range from the database rather than from a number in the test.](https://engineer.company/portfolio/wrote-tests-for-the-checkers-themselves-149/) - [Found the commit hooks and the quality gate running different checks while a document promised they were the same, by comparing the two lists in a test — the five that only ever ran by hand were the ones reading the CV prose.](https://engineer.company/portfolio/found-the-commit-hooks-and-the-gate-disagreeing-150/) - [Rehearsed the forge‑side CI hook and found two defects unreachable by reading the file: a fallback that put an unresolvable argument on the hook's input, and git's own environment variable following the gate into the checkout and turning 19 tests red.](https://engineer.company/portfolio/rehearsed-the-forge-side-ci-hook-151/) - [Moved every user‑facing string out of Python into a content tree of 874 files across three languages, after finding dead translations nobody could see were dead and a check silently grading a third of the achievements.](https://engineer.company/portfolio/moved-every-user-facing-string-into-a-content-tree-152/) - [Built a cross‑language content check that fails when a translation drops a figure the English states, and when a language uses notation it does not use — finding two Danish descriptions missing a metric and sixteen Ukrainian spans quoting in the English style.](https://engineer.company/portfolio/built-a-cross-language-figure-and-notation-check-153/)