The two unidentified firms she worked for since 2015 in Auckland believed she was qualified.
She was exposed by an anonymous tip-off in 2019.
A Facebook post shows Prajna Singh in December 2015 as "Senior Structural Engineer, managed Santa's installation on the Farmers Building at the corner of Queen and Victoria Streets in Auckland's CBD".
The Engineering New Zealand committee has fined her the maximum possible of $5000. She has also been convicted in court on 38 dishonesty charges.
Singh subsequently obtained an engineering degree and told the committee her dream is to become a chartered professional engineer, like she had pretended to be.
She told the committee she worked in a very busy team at the second company and when she was asked to complete seismic assessment work for a building consent authority, the directors assumed she was "a chartered member" and so she signed 32 of the 38 documents as if she was a CPEng.
She told the committee the firm's investigation "did not find mistakes which were grossly negligent or incompetent or which would lead to a risk of harm to the public".
"Ms Singh said there are many industry practice checks in place, such as internal and external peer review mechanisms, which were there as a safety net to ensure mistakes were mitigated," its findings out today said.
"We agree with Engineering New Zealand that this is an extraordinary statement to make.
"Even if Ms Singh could have conceivably considered she could rely on her work being checked by others, at the time the work was carried out, she did not even have a Bachelor of Engineering degree ... She has continually through this process diminished her own responsibility."
It ordered her to pay about $11,000 in costs for the investigation.
It quoted her saying this "is a grave mistake and a gross error in my judgment. I have never conducted myself in this way and I am ashamed of this step that I have taken. I have apologised on numerous occasions and accept my wrongdoing."
Singh said becoming a CPEng registered engineer remained a "personal and professional goal".
"I lost my way once, but it is something that I will intentionally never let happen again," the findings quoted her as saying.
Companies Office records show Prajna Singh incorporating an engineering company in March this year.
A Linkedin page lists Prajna Singh as an engineer providing structural engineering consulting and design services.
The regulation regime is loose and unable to prevent a sanctioned engineer from practising.
