Understanding Big O and Algorithmic Complexity

• * PostgreSQL 18 Released*
• * Testing is better than DSA (Data Structures and Algorithms)*
• * Pyrefly in Cursor/PyCharm/VSCode/etc*
• * Playwright & pytest techniques that bring me joy*
• Extras
• Joke

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Michael #1: PostgreSQL 18 Released

• PostgreSQL 18 is out (Sep 25, 2025) with a focus on faster text handling, async I/O, and easier upgrades.
• New async I/O subsystem speeds sequential scans, bitmap heap scans, and vacuum by issuing concurrent reads instead of blocking on each request.
• Major-version upgrades are smoother: pg_upgrade retains planner stats, adds parallel checks via -jobs, and supports faster cutovers with -swap.
• Smarter query performance lands with skip scans on multicolumn B-tree indexes, better OR optimization, incremental-sort merge joins, and parallel GIN index builds.
• Dev quality-of-life: virtual generated columns enabled by default, a uuidv7() generator for time-ordered IDs, and RETURNING can expose both OLD and NEW.
• Security gets an upgrade with native OAuth 2.0 authentication; MD5 password auth is deprecated and TLS controls expand.
• Text operations get a boost via the new PG_UNICODE_FAST collation, faster upper/lower, a casefold() helper, and clearer collation behavior for LIKE/FTS.

Brian #2: Testing is better than DSA (Data Structures and Algorithms)

• Ned Batchelder
• If you need to grind through DSA problems to get your first job, then of course, do that, but if you want to prepare yourself for a career, and also stand out in job interviews, learn how to write tests.
• Testing is a skill you’ll use constantly, will make you stand out in job interviews, and isn’t taught well in school (usually).
• Testing code well is not obvious. It’s a puzzle and a problem to solve.
• It gives you confidence and helps you write better code.
• Applies everywhere, at all levels.
• Notes from Brian
  • Most devs suck at testing, so being good at it helps you stand out very quickly.
  • Thinking about a system and how to test it often very quickly shines a spotlight on problem areas, parts with not enough specification, and fuzzy requirements. This is a good thing, and bringing up these topics helps you to become a super valuable team member.
  • High level tests need to be understood by key engineers on a project. Even if tons of the code is AI generated. Even if many of the tests are, the people understanding the requirements and the high level tests are quite valuable.

Michael #3: Pyrefly in Cursor/PyCharm/VSCode/etc

• Install the VSCode/Cursor extension or PyCharm plugin, see https://pyrefly.org/en/docs/IDE/
• Brian spoke about Pyrefly in #433: Dev in the Arena
• I’ve subsequently had the team on Talk Python: #523: Pyrefly: Fast, IDE-friendly typing for Python (podcast version coming in a few weeks, see video for now.)
• My experience has been Pyrefly changes the feel of the editor, give it a try. But disable the regular language server extension.

Brian #4: Playwright & pytest techniques that bring me joy

• Tim Shilling
• “I’ve been working with playwright more often to do end to end tests. As a project grows to do more with HTMX and Alpine in the markup, there’s less unit and integration test coverage and a greater need for end to end tests.”
• Tim covers some cool E2E techniques
  • Open new pages / tabs to be tested
  • Using a pytest marker to identify playwright tests
  • Using a pytest marker in place of fixtures
  • Using page.pause() and Playwright’s debugging tool
  • Using assert_axe_violations to prevent accessibility regressions
  • Using page.expect_response() to confirm a background request occurred
• From Brian
  • Again, with more and more lower level code being generated, and many unit tests being generated (shakes head in sadness), there’s an increased need for high level tests.
  • Don’t forget API tests, obviously, but if there’s a web interface, it’s gotta be tested.
  • Especially if the primary user experience is the web interface, building your Playwright testing chops helps you stand out and let’s you test a whole lot of your system with not very many tests.

Extras

Brian:

• Big O - By Sam Who
• Python 3.14.0rc3 has been available since Sept 18.
  • Python 3.14.0 final scheduled for Oct 7
• Django 6.0 alpha 1 released
  • Django 6.0 final scheduled for Dec 3
• Python Test Static hosting update

Joke: Always be backing up