What is the standard of review for questioning whether a defendant received effective representation?

The standard of review when questioning whether a defendant received effective representation is well established. "In order to establish a claim for ineffective assistance of counsel, a defendant must show that his or her counsel's performance was deficient and that the defendant suffered prejudice as a result of such deficient performance. [Citation.] To demonstrate deficient performance, defendant bears the burden of showing that counsel's performance " "fell below an objective standard of reasonableness ... under prevailing professional norms." " [Citation.] To demonstrate prejudice, defendant bears the burden of showing a reasonable probability that, but for counsel's deficient performance, the outcome of the proceeding would have been different." ( People v. Mickel (2016) 2 Cal.5th 181, 198, 211 Cal.Rptr.3d 601, 385 P.3d 796.)