Window Functions, Joins, CTEs and Subqueries
Once you've got filtering and grouping down, SQL starts asking harder questions. Which doctor handles the most visits? Which department has the most…
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A REST API State Machine for Email Verification
Email verification looks like a small feature: create a token, send a message, and accept the token when the user clicks it. In a production backend…
Our second process carries its own copy of the schema: nine of twelve tables, five of them ever queried, and not one write
Our quiz app is two deployed things. A Next.js app, and a long-lived WebSocket server that holds the game clock, because a serverless function canno…
Our data export contains the log of our data exports, so each copy is one row longer than the last
Two of the GDPR rights our users have are buttons in the app. Export your data, and delete your session history. Both of them write a row to this ta…
How to Build an IT Asset Assignment and Return System (SQL + REST API)
Imagine your company has 50 employees and 80 IT assets, including laptops, monitors, and smartphones. An employee leaves the organisation. HR confir…
A school discount with no code, because the discount is the email domain
We used to give schools a discount code. A teacher asked for one, we minted it, and then we maintained the parts that follow from a code existing: a…
Supabase RLS breaking change (Oct 30, 2026): 5-minute check to avoid 42501 errors
Oct 30, 2026, Supabase is enforcing a breaking change for RLS grants in the public schema. Existing tables are unaffected; new tables created after…
PostgreSQL Constraint Naming Convention: Which Pattern to Use, and How to Find the Names That Drifted
Disclosure: I build Schemity , a desktop ERD tool - this post is from our blog and uses it for the examples. TL;DR: Use the pattern PostgreSQL alrea…
🔎 Building IncidentCopilot: Designing a Deterministic Log Correlation Engine
Milestone 4 of IncidentCopilot — an open-source, local-first AI DevOps Incident Copilot 📌 Introduction Logs are plentiful during outages — the chall…
why pg‑bouncer can still choke your service under burst load
problem statement in a typical microservice, each instance opens its own pg client pool. during a traffic spike the aggregate connection count can e…
Our audit log has 64 actions, 17 of them are also analytics events, and one field is deliberately dropped on the way
Nakodo has 77 call sites that look like this: await audit ({ action : " campaign.launched " , userId , entityType : " campaign " , entityId : campai…
Postgres Logical Replication: Slots, DDL, and Failover
At 2 a.m. on a Tuesday, a client's reporting replica silently stopped applying changes. The publisher kept accepting writes. The replica kept answer…
Joins In PostgreSQL
Joins are one of those topics where everyone nods along when you explain them, then freezes up the moment they have to write one on the spot, in fro…
AI code review just delayed PostgreSQL 19. Finding bugs is now cheap and fixing them isn’t.
PostgreSQL 19 was supposed to ship in October. The release team now says general availability is November 19, with RC 2 on November 12 (postgresql.o…
I'm building an open-source platform for your database, API, auth and apps
I'm Duc. Since May 2025 I've been building Excalibase on nights and weekends, next to my day job. It started as a GraphQL engine for Postgres, becau…
Wait, How Did Hackers Steal the Encryption Key Too?" 5 Supabase Security Traps I Fixed in Production
Introduction: The Headline That Made My Stomach Drop Almost every week, we see another headline about a major tech company or hot startup suffering…
PostgreSQL EXPLAIN ANALYZE: What I Actually Look At in Query Plans
PostgreSQL EXPLAIN ANALYZE: What I Actually Look At in Query Plans Every slow query I have ever chased started the same way: someone guessing. "Prob…
One Null in the Subquery and Your NOT IN Returned Nothing
Marketing wanted a list. Every customer who had never placed an order. The query was short and read like English. Select from customers where id is…
One optional phone number, eleven files, five kinds of empty, and no migration
Yesterday I added an optional phone number to Nakodo. When a creator or a business says yes to a brand, the app introduces them by email, and the br…
Setting an env var above your imports does not run before them, and our integration test works anyway
The largest test file in PubTrivia is 543 lines, and it has no mocks in it. It calls the actual server actions a player's phone calls, and the actua…
Gate your app on a Postgres migration job with service_completed_successfully (and the DNS race that broke our deploy)
Originally published on the Hubfly blog . TL;DR What you get: a 3-service Compose file (Postgres, a one-shot migration job, an API) where the API ca…
Why Your Coding Agent Forgets Your Refactors (And How I Fixed It in PostgreSQL)
This is a submission for the MLH x DEV Writing Challenge What I Built Here is a bug that drove me crazy for three days straight. You ask an autonomo…
OpenSparrow v4.2 adds native Excel export, column masking for viewers
OpenSparrow v4.2 adds native Excel export, column masking for viewers, and record‑tooltips in drilldowns — plus a handful of UI polish and stability…
Why Your Connection Pool is Lying to You
We hit a wall last month. Traffic was stable, CPU was idle, but p99 latency spiked to 2s. The PostgreSQL server looked healthy. The culprit wasn't t…
I built a Supabase-style query client that talks directly to Postgres
I like the Supabase JS client. .from('todos').select('id, task').eq('done', false) reads like what I mean, and { data, error } means I'm not wrappin…
Reengineering Family Finance: Building Financial Integrity Into Kith
Families manage money and responsibilities in ways that often resemble small organizations. They coordinate recurring contributions, fund shared pro…
Mastering PostgreSQL Connection Pooling in Node.js and TypeScript Services
Most database crashes in Node.js apps don’t happen because of heavy queries. They happen because of unmanaged connection pools. When your TypeScript…
Similarity search and a time range, in one Postgres hypertable
Operator notes are time-series data. Each one has a timestamp, a site, a temperature, and a sentence about what happened. Searching them by meaning…
RAG Tenant Isolation Inside the Vector Index
Put the user filter inside the vector search itself. If you search everything and remove other people’s chunks afterwards, those chunks still use up…
Idempotency keys done right: exactly-once effects over at-least-once networks
Why "just retry" creates duplicate payments, and a PostgreSQL-backed design for idempotency keys that survives double clicks, timeouts, crashes and…