Andrei Rebrov did not set out to build a fintech company. He set out to fix a blindspot he kept running into while working directly with e-commerce brands.
The pattern was always the same. Founders looked at their revenue numbers and their ROAS and felt good about where things were going. Then you pulled back the curtain and looked at what was actually happening at the unit level: the real cost of goods, what fulfillment was eating, how returns were hitting margin, what the ad spend truly cost per profitable order. The picture was almost never what people thought it was. Brands were scaling losses without realizing it, and there was no simple connected tool giving operators a real-time view of the truth.
That gap is what Finsi is built to close. It connects to Shopify, Amazon, and ad platforms and automatically surfaces contribution margins, true CAC, and per-order profitability broken down by product, channel, and SKU. No finance team required. No spreadsheet archaeology.
We sat down with Andrei to talk about what he's learned building it.
Finsi.ai is an AI-powered, operator-focused analytics and growth platform designed for e-commerce, direct-to-consumer (DTC), and subscription brands. It functions as an "AI growth co-pilot," designed to replace traditional, fragmented dashboards with actionable, AI-driven recommendations to increase customer lifetime value (LTV), reduce churn, and optimize advertising spend.
Finsi is a financial analysis tool that helps e-commerce brands understand their unit economics and profitability. It connects to Shopify, Amazon, and ad platforms to automatically calculate contribution margins, customer acquisition costs, and true profitability at the product and order level, giving DTC brands the financial clarity they need to scale profitably.
Working closely with e-commerce brands, I kept seeing the same pattern: founders thought they were profitable based on revenue and ROAS, but when we dug into the real numbers — COGS, fulfillment, returns, ad spend — the margins told a completely different story. Brands were scaling losses without knowing it. That was the moment it clicked: there was no simple, connected tool that showed DTC founders their true unit economics in real time.
Most brands focus on top-line revenue and ROAS as their north star metrics, treating them as proxies for profitability. But ROAS doesn't account for COGS, returns, shipping, or payment fees. You can have a 4x ROAS and still be losing money on every order. The real problem isn't driving sales — it's understanding which sales are actually profitable.
I've spent years working in e-commerce and growth, operating at the intersection of marketing and finance. I saw firsthand how difficult it was to get a clear financial picture when data was scattered across Shopify, ad platforms, and spreadsheets. My background in both growth and analytics gave me the perspective to build a tool that bridges the gap between marketing metrics and real financial outcomes.
The contribution margin dashboard. The moment brands connect their data and see their true per-order profitability — broken down by product, channel, and SKU — it's a revelation. It often changes how they think about their entire business. That "aha" moment of seeing real numbers instead of vanity metrics is what users remember most.
Most financial tools are either generic accounting software (built for accountants, not operators) or basic analytics dashboards that only show marketing data. Finsi is purpose-built for e-commerce operators — it automatically pulls in all cost layers (COGS, shipping, returns, ad spend, fees) and calculates true contribution margins without requiring a finance team or manual spreadsheet work. It speaks the language of DTC founders.
The era of growth-at-all-costs in e-commerce is over. Brands that scaled aggressively on cheap capital are now facing the real consequences — thin or negative margins, rising CACs, and no path to profitability. The shift toward profitable, sustainable growth is the defining challenge of the next few years, and most brands still don't have the financial infrastructure to navigate it.
Don't build features — solve problems. Early on, it's tempting to keep adding functionality based on every piece of user feedback. But the hard lesson is that focus is a superpower. Doing fewer things exceptionally well beats doing many things adequately. The brands that got the most value from Finsi early on weren't the ones who needed more features — they were the ones who truly committed to understanding their unit economics.
I would talk to more customers before writing a single line of code. I spent time building assumptions into the product that turned out to be wrong. The pain points were real, but the specific workflow and presentation customers needed was different from what I had imagined. Getting deep qualitative insight from 20 potential customers upfront would have saved months of rework.
Do things that don't scale. It sounds counterintuitive when you're building a SaaS product, but the founders who win early are the ones who manually onboard every customer, jump on calls at odd hours, and do whatever it takes to make early users successful. That obsession with early customer success is what generates the word-of-mouth and the product insights you can't get any other way.
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