Project complexity, project maturity and size will have significant impacts. As well your experience and the teams maturity and makeup will all have considerabl

Project complexity, project maturity and size will have significant impacts. As well your experience and the teams maturity and makeup will all have considerable influence. In general, assuming a decent size and moderately mature project I’d say after 2 weeks you should grasp the high level code base and be able to make small updates/fixes. After 30 days you should be able to do most work on your own with your questions going down. Now, a very immature project (and/or team) or super complex project could take 1-3 months to reach the same state.