Engineering researcher. APIs, databases, infrastructure, systems design.
The FILTER clause turns multi-pass conditional-aggregate queries into single-pass scans. Most teams writing 2026 Postgres code still reach for CASE WHEN inside SUM. There is a cleaner way that has been standard SQL since 2003.
A webhook subscription endpoint that accepts any URL eventually accepts URLs that point to localhost, private networks, expired domains, and the wrong customer. Validating at subscription time is much cheaper than validating during every delivery.
Galileo noticed in 1583 that a swinging chandelier kept time independently of its swing amplitude. It took 70 years and a Dutch mathematician to turn the observation into a working clock that made time precise to the second.
Postgres has had COMMENT ON since version 7 in 2002. Almost no team uses it. The cost is one extra line per object and the value is that documentation lives where the schema lives and survives every refactor.
The HTTP Deprecation and Sunset headers let an API tell clients which endpoints are deprecated and when they will stop working. Most APIs do not use them. The reasons are mostly cultural, and the small group of APIs that do use them get most of their value from the surrounding discipline.
Postgres 16 added pg_stat_io, a system view that exposes I/O activity broken down by backend type and I/O context. It closes a long-standing observability gap. Most teams have not noticed the view exists yet.
Hard limits return errors. Soft limits warn the customer that they are approaching the threshold so the customer can adjust before the hard limit fires. The patterns that work are simple but underused in B2B SaaS.
The schoolroom version of the steam engine credits James Watt as the inventor. The actual history runs through Thomas Newcomen's 1712 atmospheric engine, which operated commercially for sixty years before Watt improved it, and through Hero of Alexandria's working steam toy 1700 years earlier.
The pg_locks system view shows every lock currently held or waiting in the database. Most teams reach for it during an incident and discover the columns are not obviously interpretable. The structure is worth understanding before the next incident.
Postgres 12 changed the default behavior of CTEs from optimization-fence to inlineable. This was almost always an improvement, but the cases where the old behavior was actually load-bearing are worth understanding.
Most webhook docs describe the signing mechanism. Far fewer describe how to rotate the signing secret without breaking every customer integration. The patterns that work are simple but underused.
The reflexive answer to 'we need a job queue' is Redis, RabbitMQ, or SQS. The unreflective version of that answer skips a Postgres feature that turns a single table into a job queue with semantics that match what most teams actually need: SKIP LOCKED.