The performer - Marina Kovalova, completed the work at a high professional level and actually saved my project. The EPUB file I provided did not pass validation on several platforms, and I was already at a dead end. The typesetter promptly reworked the file, corrected technical errors, cleaned up the structure, and prepared a perfect EPUB that successfully passed all checks on the first attempt.

The work was done neatly, qualitatively, and in full compliance with the requirements of publishing services. I would like to specifically note the attention to detail, competent communication, and quick response to questions. The collaboration was comfortable and absolutely professional.

I recommend the performer to all authors who value quality, reliability, and technical accuracy. I will definitely reach out again.