Thinking of going niche: Starting an agency focused only on fintech products (but here’s the catch...)

So here's the thing — the agency market is super saturated. Every second agency is offering MVP services, full-stack dev, SaaS builds, and whatnot.

But I’ve been thinking: instead of going broad, what if I go narrow?

I'm planning to start an agency that builds only fintech products.
Stuff like:

• UPI-integrated apps
• Digital wallets
• Payment infrastructure
• Blockchain-based platforms
• Lending dashboards
• KYC + AML integrations
• Smart contract systems

The problem? We haven’t built a fintech product yet.

We did build a B2C SaaS in the consumer tech space, and we’re devs at heart — comfortable with complex backend logic, security layers, and scalable infra. But there’s no "fintech" label in our portfolio yet.

So I have two questions for this community:

1. How do you gain trust from fintech clients when you're just entering the niche? Even if you have solid dev skills, people want to see a relevant track record. Any tips on how to build that early credibility?
2. Where do fintech startups hang out or look for dev partners? Are there specific forums, marketplaces, founder circles, hackathons, or Discord/Telegram groups where early-stage fintech builders look for product teams?

I’m not trying to pretend we’ve already done it. Just being transparent — and very focused.

If you’re in fintech or have broken into it as a dev agency, I’d love your advice or feedback.