An appeal de novo, is a trial de novo. That is a new trial.
Cities cheat. They will include the hearing officer's decision in their lodging of evidence. Make certain the hearing officer's decision is eliminated. This is a brand new trial.
Any city that includes the hearing officer's decision or any information is prejudicial. Supreme court case law excludes it. A hearing officer is to be given NO deference. You need to make certain the entire city lodged file or at least the hearing officer's conclusion why you are guilty is omitted including perhaps the entire record of oral testimony with the hearing officer. A new trial is a new trial. A judge would need to decide.
File a motion before your first appearance to exclude anything to do with the hearing officer.
This is an important case. The case clarifies why the proceeding is a appeal de novo. Constitutionally a superior court cannot review an administrative decision. Read the whole decision. Collier & Wallis, Ltd., v. Astor, 9 Cal. 2d 202, 70 P.2d 171 (1937).

