He had undeniable aptitude for the profession of engineer and his in-depth knowledge of Moldavian law was to make him an indispensable man at a time when problems of organization and legislation were brought to the fore.

[8] All the data about Costache Conachi, corroborated with the testimonies of reliable foreign observers, highlight his culture, seriousness, tact and frugality - rare qualities in the corrupt and ignorant environment of the boyar oligarchy in the time of the phanariots.

In the well-documented memoir he wrote in 1834, the French consular agent Bois le Comte[n 4] depicts him as follows: „Under soft, caressing and shy forms, he hides instruction, a rather delicate spirit“.

As for Saint-Marc Girardin, he discovered in Conachi „a figure such as I imagine those of the eighteenth century: something mocking and sardonic; but his sarcasm was directed against vice“.

[7]: 391 Preoccupied with astronomy, he bought from Vienna all the instruments necessary to establish an observation tower, including a telescope, bequeathed to the Society of Physicians and Naturalists; as a "geometer and boundary marker" he established boundaries and drew up plans of the boyars' estates[2] In the literary field, Costache Conachi is regarded by many as the first true Romanian poet of his time.