This isn't confined just to senior developers. I have even encountered system architects who were clueless about Isolation levels. Some even confused "Consistency" in ACID with the "Consistency" in CAP.
Makes me sad, since I work mostly in retail and and encounter systems that are infested with race conditions and simila errors: things where these isolation levels would be of great help.
However it's mostly engineers at startups, I have a very high opinion of typical Oracel/MSSQL developers at BigCos who at least have their fundamentals right.
Some time ago, this was important to decipher the marketing behind MongoDB. Their benchmarks ran with a loose isolation (read_uncommitted iirc) that didn't guarantee a durable flush, and they'd benchmark against defaults from postgres, etc, which didn't use this isolation.
Clearly it worked for them, but I spent a few different stints cleaning up after developers who didn't know this sort of thing.
In over 25+ years at various companies, I only recall one interview where isolation levels were even discussed. Almost nobody cares until it's a problem.
we must have had entirely different careers, same in years and 180 degrees opposite, absolute core (and disqualifying) questions at every interview, no exceptions.
One "enterprise" HR product I had to interact with stored all its data in a single MS SQL Server table, with hundreds of columns. It was basically a spreadsheet based system with an SQL interface. This was more than a decade ago, but still.
About 20 years ago, I worked at a startup where one of the guys had built his own ORM. It was never clear why. Internally, it didn't use prepared statements, and instead used some custom escaping logic that was full of bugs. We'd regularly get SQL injection issues in production.
Makes me sad, since I work mostly in retail and and encounter systems that are infested with race conditions and simila errors: things where these isolation levels would be of great help.
However it's mostly engineers at startups, I have a very high opinion of typical Oracel/MSSQL developers at BigCos who at least have their fundamentals right.