I agree with some of the other comments here that this article seems to be based on little research. As a fellow software professional, you should be aware of the standards that apply to all airborne software, namely DO-178 / ED-12 either edition B or C.

If you had ever worked on avionics software yourself, you would certainly know them.

These give all of the software development requirements that must be adhered to, by any manned avionics connected equipment manufacturer worldwide, not just in US. No way can any shortcuts be made, as all avionics software is fully audited to ensure it conforms, and is certificated as such by the regional authorities before it can fly.

So I don’t believe in this case, economising on software can possibly be to blame, because for sure all of the critical software on that Boeing plane will be fully conformant with those very rigorous standards.

The standards themselves cost money to obtain legally, but many examples of informative documents around them are freely available to download from many reputable sources.