A penetration test is a scoped, authorised attempt to find and prove weaknesses before someone with bad intentions does. A good one is a structured project, not a surprise.
Scope and rules of engagement
We agree in writing what is in scope (applications, APIs, networks, cloud accounts), what is not, when testing may happen, and who to contact if something breaks.
Testing
Testing combines automated tooling with manual work: authentication and session handling, access control, input validation, business logic and configuration review. Methodologies such as the OWASP Web Security Testing Guide and PTES structure the work.
Reporting
Every finding should include evidence, the impact in plain language, a severity rating and a concrete fix. You should be able to hand the report to an engineer and have them act on it.
Retest
Fixes are only real once they are verified. A retest confirms that remediated issues are closed and updates the report accordingly.