Accepted an MNC offer, later got a higher-paying startup offer — struggling to decide. Looking for advice.

I’m a Senior Full Stack Engineer with ~6 years of experience, based in India. I recently accepted an offer from a well-established MNC (financial services domain). They made the offer knowing I have a 90-day notice period, which I appreciated, and the compensation is solid with strong benefits and stability. After accepting this offer, I received another offer from a Series-A startup (US-based product company) with higher fixed pay, strong engineers, and what seems like faster learning and ownership. The work and tech stack genuinely excite me. I’m now conflicted because: I’ve already accepted the MNC offer and value integrity The startup could accelerate my technical growth long-term I currently don’t have major financial liabilities, but my spouse is going through some job uncertainty, so stability matters too For people who’ve faced a similar choice: Is it worth backing out after accepting an offer if the startup opportunity seems better for long-term career growth? How much weight should I give to stability vs acceleration at this stage of my career? Any regrets from choosing either path? I’m trying to make a decision I won’t regret 2–5 years down the line. Would really appreciate perspectives from folks who’ve been through something similar. Thanks in advance.