# Performance Tuning > Selected Engineer ApS work demonstrating Performance Tuning — 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/) - [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/) - [Designed, deployed, and maintained 10 PostgreSQL and MS SQL servers on Ubuntu Linux VPS, ensuring optimal server performance and reliability.](https://engineer.company/portfolio/designed-deployed-and-maintained-10-postgresql-and-ms-13/) - [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/) - [Directed full‑stack GIS map development, overseeing PostgreSQL, Mapbox, ReactJS, and NodeJS to deliver an integrated solution.](https://engineer.company/portfolio/directed-full-stack-gis-map-development-overseeing-postgresql-25/) - [Overhauled internal processes, saving 8,000 hours by improving software architecture, systems, and scheduling efficiency.](https://engineer.company/portfolio/overhauled-internal-processes-saving-8-000-hours-by-38/) - [Enhanced project efficiency, saving 150 hours per month across 30 projects by optimizing workflows and resource management.](https://engineer.company/portfolio/enhanced-project-efficiency-saving-150-hours-per-month-46/) - [Administered 40 websites on Ubuntu Linux hosting servers with Apache and Nginx, ensuring high availability and performance.](https://engineer.company/portfolio/administered-40-websites-on-ubuntu-linux-hosting-servers-53/) - [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/) - [Adopted UUID v7 time‑ordered identifiers (PostgreSQL 18) as entity keys to reduce B‑tree index fragmentation and speed up queries.](https://engineer.company/portfolio/adopted-uuid-v7-time-ordered-identifiers-postgresql-18-64/) - [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 the Next.js 16 frontend with deliberate SSR, SSG and CSR strategies, and a reusable prefetched‑server‑page factory that removes the N+1 fetch cascade from each authenticated page moved onto it.](https://engineer.company/portfolio/built-the-next-js-16-frontend-with-deliberate-73/) - [Delivered full Progressive Web App support — installable and offline‑capable — with Workbox runtime caching via next‑pwa.](https://engineer.company/portfolio/delivered-full-progressive-web-app-support-installable-and-74/) - [Moved slow work off the request path onto a River job queue — 15 worker modules, 8 scheduled tasks and 20 pg_cron jobs — so a request returns while the work behind it carries on.](https://engineer.company/portfolio/moved-slow-work-onto-a-river-job-queue-97/) - [Built fail‑closed abuse controls — 22 Redis‑backed rate limiters, Cloudflare Turnstile, request idempotency and an origin lock — so the platform sheds bots and floods instead of trusting its callers.](https://engineer.company/portfolio/built-fail-closed-abuse-controls-and-rate-limiting-100/) - [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/) - [Ran the whole company on one 512 MB single‑core host — a git forge, a web server serving seven domains, Tor, two alternate‑protocol servers, backups and intrusion banning — by treating 464 MB of usable memory as the binding architectural constraint.](https://engineer.company/portfolio/ran-the-whole-company-on-one-512mb-host-109/) - [Built dead‑man's‑switch monitoring that pings only while memory and disk are healthy, so a degraded host raises an alert by going silent — and caught six variable names saying "free" where the check correctly measured "available", an order of magnitude apart on a 464 MB box.](https://engineer.company/portfolio/built-dead-mans-switch-monitoring-115/) - [Built a multilingual static site in Hugo across 104 template files including 49 partials, publishing every page in four representations from one content tree in three languages.](https://engineer.company/portfolio/built-a-multilingual-static-site-in-hugo-126/) - [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/) - [Cut the stylesheet bundle from 87 KB to 31 KB by taking a base64 font out of it, and dropped 756 KB across 22 files that were published on every deploy and referenced by nothing.](https://engineer.company/portfolio/cut-the-stylesheet-bundle-from-87kb-to-31kb-139/) - [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/) - [Stopped an application filling memory at 41 MB a second — a recorded 111 GB of compressed pages on a 36 GB machine — by bounding every event stream, subscribing by event type and putting a rate budget on logging, taking 610,996 log lines down to 1,411.](https://engineer.company/portfolio/stopped-an-application-filling-memory-at-41mb-a-second-155/) - [Adopted Swift 6 complete strict concurrency with no actors, bridging a blocking C event loop to the main actor through one producer, one consumer and one ordering — after establishing that a task per event loses the ordering the interface depends on.](https://engineer.company/portfolio/adopted-swift-6-strict-concurrency-over-a-c-event-loop-156/) - [Took the test suite from six tests over a sixty‑second limit to 135 passing in 8.9 seconds by profiling the main thread and removing the two calls it sat inside for 3,989 samples out of 4,017.](https://engineer.company/portfolio/took-the-test-suite-under-nine-seconds-158/)