Am i in trouble for faking number of years on my resume

Lying on your resume works, but it's kind of like being the person who always "takes a penny" and never leaves one in the "take a penny leave a penny" jar. If everyone takes a penny, there's nothing left for anyone, including the people who actually need a penny. RE: Background checks. It will absolutely come up with legit companies that run standard background checks through Hire Right and Checkr, etc... What will happen is it will come back as "unable to verify" and the consequences are up to the company to decide if they care or not. Some companies care about date discrepancies and some don't, and the magnitude of the discrepencies matter. I know a common strategy amongst alum from Codesmith is to exaggerate on their resumes with a footnote that their experience is "developed under OSLabs". When it comes to the background check, even though it's on the resume, a person can not include it and be like "oh this was just open source unpaid project work, not a job" and the background check company won't even attempt to verify it and the hiring company won't even get flagged a discrepency. I've seen all kinds of background check things come up and it's very case by case, but lying can often get through if you keep the lie going sadly. I personally am strongly against lying - it might not catch up to you until later on, even if you get that first job. It might come up in the future in far more meaningful ways that really hurt you if you don't proactively mange the situation.