Sami Ullah uses PostgreSQL as the main database for his full stack and NestJS projects. He designs schemas with constraints that enforce business rules, such as preventing double bookings, adds indexes based on real query plans, and uses PostGIS when an application stores locations or field boundaries.
Used professionally since 2025 (1+ years)
I treat PostgreSQL as more than storage. Constraints, partial unique indexes and exclusion constraints can enforce rules that application code alone gets wrong under concurrency.
When a project stores coordinates or polygons, PostGIS lets me query them directly in SQL instead of loading everything into Node.js.
Official documentation: PostgreSQL documentation
Own product
JobPilot is my own web app for remote job hunting. Every day it collects new remote jobs, scores each one against a master CV, writes a tailored CV and cover letter for good matches, and waits for a human to approve before anything is sent. It supports several job seekers in separate workspaces and can also be driven from an AI assistant through MCP.
Own product
A multi-salon booking marketplace I designed and built for Pakistan. Clients find nearby salons on a map, choose a barber, service and time, and book at the salon or as a home visit. Salons run staff, schedules and earnings from their own dashboard, and the platform collects a commission per completed booking through daily settlements.
Own product
ReviewLens (working name) is a SaaS I built for online stores. It reads a store's customer reviews, returns and competitors and turns them into a short report: what customers complain about, which products cause the most problems and what to fix first. All numbers are computed in code, and AI only classifies text and explains the results.
#postgresql6 min
How to prevent double booking in PostgreSQL: a booking schema with tstzrange, a btree_gist exclusion constraint, and clean 23P01 handling in NestJS.
read →
#postgresql6 min
A PostGIS introduction for web developers: geography vs geometry, nearby search with ST_DWithin, GiST spatial indexes, and GeoJSON output for Leaflet maps.
read →
#nestjs6 min
How to build NestJS JWT refresh tokens properly: short-lived access tokens, rotated refresh tokens stored as hashes, httpOnly cookies and reuse detection.
read →
Use an exclusion constraint on a time range per resource, for example EXCLUDE USING gist (doctor_id WITH =, tstzrange(starts_at, ends_at) WITH &&), with the btree_gist extension enabled. The database then rejects any overlapping booking even when two requests arrive at the same moment, which application checks alone cannot guarantee.
Yes. His CV lists both PostgreSQL and MySQL. MySQL comes up most with WordPress sites, which run on it by default. For new custom applications he prefers PostgreSQL for its constraint types, JSONB columns, range types and the PostGIS extension for geospatial data.
Use PostGIS when the app needs spatial queries: finding stores within a radius, checking whether a point falls inside a field boundary, or measuring polygon areas. Doing this in SQL with spatial indexes is much faster than loading every shape into application memory and filtering there.