How much is one million lines of code?

If a senior engineer works in a well-defined, well-architected greenfield project, and does extensive tests, 10,000 lines of code written in one year are very productive. The amount of new code per person-year will be much less in larger projects - a good indicator is the line count and the estimated value of the Linux kernel (40 million lines in 2025, redeveloping it in 2011 would have already cost 2200 million Euros, which would pay e.g. 36000 person-years for mid-level German software developers, that would mean 1111 lines per person-year{actually about half of that because of the interim growth of line count in the meantime }- and most software projects can only dream about so much actual value.)

So, you can say 1,000,000 lines of code generated in 11 days are probably 100 person-years of technical debt.

One caveat: It is relatively simple to auto-translate code in restricted languages like Java, Python, or Rust to unrestricted languages like C or C++. In that case, enforced invariants (like "no use of freed memory" or "sharing data across threads xor mutation") become implicit, but verbatim translation is often possible.

The other direction will require a re-design..