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Coupling and Cohesion: Two Concepts Every Developer Should Understand

Lately, I've been spending quite a lot of time learning about design patterns and software architecture.

And the deeper I go, the more often I come across two concepts that seem to be behind almost everything: coupling and cohesion.

They may sound abstract at first, but they actually describe two very practical things:

How strongly are different parts of the system dependent on each other, and how well do the responsibilities inside a component belong together?

PostgreSQL After Many Years with MySQL: What Surprised M

For the last several years, MySQL has been my primary database.

PostgreSQL came up from time to time, but I never had a real reason to dive deeply into it.

That changed when I started working on a new project — an AI assistant. The project required PostgreSQL, JSONB, Full-Text Search, and, most importantly, pgvector for vector search.

After spending some time working with PostgreSQL more seriously, I realized that it is not just “another SQL database that is more or less like MySQL”.