I replaced a five day spreadsheet with a cron job, then spent two weeks fixing what I got wrong
Every twenty or twenty five days someone at the company would sit down and build a rate card. A rate card is a spreadsheet. Countries down one side,…
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PostgreSQL Cheat Sheet: Investigating and Terminating Database Blocking Sessions
If you run PostgreSQL in production for a long time, you will probably see this problem at some point: Queries start waiting. Connections increase.…
One Gigabyte per Survey, of Which 108 KB Goes in the Database
Here is the disk layout of one mobile mapping survey — a vehicle with a LiDAR scanner and a panoramic camera, driven along a road: data/001_MMS/ 507…
Postgresso 7-8 (92-93)
PGW: A PGBACKREST INTERLUDE: (Andreas Scherbaum, Jimmy Angelakos) Andreas Scherbaum and Jimmy Angelakos presented a quantitative analysi…
Designing the Learning Progression Engine Behind Codervai CP
Originally published at parvejshah.com/blog/scaling-competitive-programming-lms-architectures by Parvej Shah . Competitive programming requires buil…
UUIDs explained — the uniqueness myth, the version you should be using, and the database mistake that slows everything down
You've generated thousands of UUIDs without thinking twice. id column, default value, done — a 36-character string that looks like f47ac10b-58cc-437…
Schema catalogs for AI assistants: the layer nobody wants to maintain
The schema catalog for an AI assistant is the artefact that answers the question "what does this database look like right now". Whether the database…
40001 is not a query error
The PostgreSQL manual is unusually direct about this: When an application receives this error message, it should abort the current transaction and r…
MCP vs. a Direct Database Connection: A Security and Workflow Comparison
Sooner or later, someone on your team wants to point an AI assistant at the production database. Maybe it's a support engineer who wants to answer "…
One View Per Layer: Four Sharp Edges I Found in My Own Code
There is a layer in my database called 1 . Somebody created it, presumably by accident, and it sat there for months looking harmless. It was the onl…
Why Your OAuth Integration Randomly Returns invalid_grant (and How to Stop Two Workers From Racing)
If your third-party OAuth integration works for days and then dies with {"error":"invalid_grant"} , the cause is usually not clock skew, a wrong cli…
A rate limiter changes when it leaves memory
A rate limiter changes when it leaves memory Rate limiting can start with a Map and a counter. That is enough for a single process. The design chang…
Same Zone, Same Projection, 427 Metres Apart
I was writing a blog post about the architecture of a system I built when I found a bug in it. This is that bug, and the much more interesting thing…
PostgreSQL psql: Schema Navigation Quick Reference
A short refresher for navigating PostgreSQL databases, schemas, and objects from the psql command line. Schemas List all schemas: \ dn List schemas…
Postgres as your message queue is a SPOF you'll regret at 3am
At 3 am the pager is activated. Your queue is backed up, your database is on fire, and those two facts are the same fact. This is the trap nobody wa…
How I Stop Webhook Replay Attacks in Node.js & PostgreSQL
Handling payment webhooks sounds straightforward—until network retries hit your server three times in a row, or an attacker intercepts a valid paylo…
The Notification Born out of Love: Building an Adaptive Geofencing Engine for Digital Wallets
The Story: A Simple Requirement Meets Too Much Curiosity A while ago, I received a fairly straightforward ticket in our sprint: "Allow users to add…
Managed Cloud Databases with Aiven: Multi-Cloud Resilience, Infrastructure as Code, and Cost Optimization
Running production databases on cloud infrastructure presents a persistent engineering tradeoff. Managed database services provided by major cloud v…
Row-level security in Symfony: the role that ran your migrations bypasses every policy you wrote
A comment on my last article was better than the article. The subject was single-database multi-tenancy, and @to21as argued that the predicate shoul…
The AI demo failed, but the database remembered half of it
This is a submission for DEV's Summer Bug Smash: Clear the Lineup . The error message said the operation had failed. PostgreSQL told a different sto…
How to Drop All Tables in PostgreSQL Safely (2026)
Why you are here You ran a migration that went sideways, or you are resetting a local dev database, or a test suite needs a clean slate. The psql co…
Your RLS Policy Passed Its Test For the Wrong Reason
A manual psql check answers exactly one question: does this policy work right now, against today's schema, with today's roles. It says nothing about…
Powerful regression tests for your PostgreSQL project
Mark (aka Winsaucerer) here to show you how you can test your PostgreSQL database like a sorcerer. We are going to be using Spawn, a SQL build syste…
[Перевод] Пайплайним Postgres из руби‑файберов
Как я собрал на чистом Ruby мультиплексор поверх pipeline mode из libpq, обогнал классический пул соединений на 27% при вдвое меньшем числе коннекто…
Column Comments in PostgreSQL and MySQL: How to Document Columns Without a Migration
Disclosure: I build Schemity , a desktop ERD tool - this post is from our blog and uses it for the examples. TL;DR: The database has a built-in plac…
Buying a phone number is a distributed transaction
The API makes it look trivial. const number = await carrier . numbers . buy ({ phone_number : " +1... " }); await db . insert ( " rented_numbers " ,…
Архитектура движка подбора билетов: три GDS, железная дорога и маршрут, который меняют в дороге
Референсная архитектура движка подбора билетов на redb: канонная модель, Scatter-Gather по трём GDS и ж/д, дерево-маршрут и saga-переоформление в до…
PostgreSQL Connection String: Supabase, Neon, Railway
The short version A PostgreSQL connection string is a single URL that tells a client how to reach your database. It looks like this: postgresql : //…
Read-Only by Design: Letting AI Explore Your Database Without the Risk of Writes
There's a moment every developer hits the first time they connect an AI assistant to a real database: it works beautifully, the model writes a clean…
Self-Hosted Chatwoot: 5 Failures the Docs Don't Warn You About
I run self-hosted Chatwoot as the WhatsApp inbox for a dozen or so small Israeli businesses. Two servers, a few thousand conversations a week, a dri…