painstaking

This term conveys a sense of grueling effort and extreme precision. It suggests a process where the person is almost obsessively careful, leaving no stone unturned to avoid a single single error. It carries a positive connotation of diligence and high quality, though it implies the work was exhausting or tedious.

While similar to meticulous, painstaking emphasizes the labor and the perceived struggle involved in the process. It is typically used in professional, academic, or artistic contexts where the stakes of a mistake are high, such as in restoration, surgery, or forensic investigation.