4 ideas
A professional is someone who can work unsupervised and certify their own work as complete, without a checker standing behind them. The need for external inspection is what marks someone as merely employed. Being able to vouch for your own output is the core qualification, above skill or credentials.
Look at how someone discharges duty, not at their title, education or pay grade, and the line between professional and amateur falls in unexpected places. A driver, cleaner or clerk can be more professional than a senior executive who cuts corners. The test is conduct under low visibility, not position.
Bagchi sorts professional traits into competence, which can be learned and improved, and integrity, which cannot be traded against performance. A high performer who is dishonest in small matters, such as padding expenses or misreporting progress, is disqualified, because trust is what lets an organization operate without supervision. Small lapses are treated as signals, not exceptions.
A professional does not hide behind unclear briefs, missing information or 'no one told me'. They seek out context, close the gaps themselves, and take responsibility for the outcome even when the path was not specified. Treating ambiguity as a personal problem to solve, rather than an excuse, separates professionals from competent task-executors.