The phrase "considerable experience" means having a lot of knowledge and skills in a particular area from doing something for a long time. Full definition
Highly motivated human resources professional with considerable experience in identifying, selecting, recruiting and managing personnel looking for a position that is challenging and rewarding in a forward — looking organization. (sampleresumeobjectives.org)
Even a case that seems relatively straightforward at first glance can ultimately prove quite complex, so finding an attorney with considerable experience in personal injury actions is advisable. (frankellawfirm.com)
She has considerable experience of working in a busy marketing department and is someone who can quickly react to changes in the market place. (dayjob.com)