"gcc -S sqlite3.c" will give you an assembly language database engine. :-)

OK, maybe you meant "hand-written" assembly language. But on the other hand, SQLite claims to be written in C, yet a fair amount of that C code is automatically generated using other scripts and programs. Does that mean SQLite is not really written in C?

FWIW, we actually use assembly language sqlite3.s file (as generated above) during testing. We have scripts that go through and punch out individual opcodes, then assemble the result and verify that the test suite detects the error. This is a test of the SQLite test suite more than a test of SQLite, but a strong test suite makes for a strong product, so it still helps.