C# InterpolatedString is very close, with the twisty bit being that C# can rely on static typing for safety so the "f-string" and "t-string" variants use the same literal syntax and depend on what function they are passed to, whereas in both Python and Javascript they have different literal syntaxes. Python chose to use a different literal prefix to its literals ("f" versus "t") and Javascript chose to use a function-call syntax as prefix (`templateString` versus html`templateString` where html is a function in scope).

For the case like here it’s closer to FormattableString that’s what EF Core’s composable FromSql method works on top of. Both address custom interpolation but from different angles / for different scenarios.