The Hidden Risk in Fintech

By Teo Zavalia Gahan (Co-Founder & CPO, Rexi)

Some problems you can ignore until they hurt.
Reconciliation is not one of them.

When things are going well, reconciliation is invisible. Numbers line up. Reports look fine. Nobody asks questions.

You only notice it when something’s off — when money is missing, balances don’t match, or no one can confidently explain where funds are or where they went. That’s when reconciliation stops being a back-office concern and becomes an existential one.

When reconciliation becomes the bottleneck

While building the Insurtech division at Mercado Pago, reconciliation quickly became the bottleneck every time we launched a new payment method or onboarded a new partner.

It wasn’t just about confirming whether we got paid. The real complexity lived in the edge cases:

• Cancellations and refunds
• Voided transactions
• Mismatched transaction IDs
• Timing differences across systems

Every day, the same questions came up:

Did we actually receive the money?
Where is it right now?
Who is responsible for checking this?

Most of the time, no one had a clear answer. Teams were working with partial data across multiple systems, trusting that things would “add up by month-end.”

The $27M lesson

In 2020, at Mercado Libre, we uncovered a major reconciliation issue with Cobro Express, a cash payment provider in Argentina.

They represented only ~2% of total volume. On the surface, everything looked fine — transactions appeared valid and marked as completed.

But when we reconciled what they owed us against what was actually being deposited, the gap was massive.

There was no reconciliation between the transactional layer and the financial layer. Payments marked as completed were delayed or never settled. Internal investigations suggested some local agents were collecting cash and holding it back.

The result: a $27 million loss, recorded as bad debt.

After that incident, Mercado Pago:

• Built a dedicated reconciliation team
• Implemented Salesforce for case tracking
• Changed how it worked with providers

But the damage was already done.

The lesson was clear: without rigorous, ongoing reconciliation, even small partners can create outsized financial and operational risk.

This wasn’t a one-off

I assumed this was an isolated case. It wasn’t.

Around the same time, my co-founder Nacho was at Comun during the period when Synapse collapsed.

The team was tracking balances across multiple banks, processors, and rails — with no central source of truth. Everyone worked off different datasets. Every week, a new mismatch appeared, and the team had to scramble to determine whether it was a real issue or just a reporting delay.

Then Synapse imploded.

Hundreds of millions went missing. Founders were left in the dark. Users couldn’t access their funds. And no one could clearly answer the most basic question:

Who owns what?

It was the same problem — just at a much larger scale.

The pattern we kept seeing

Across companies, geographies, and business models, the pattern was always the same:

• Fragmented financial data
• No reliable system of record
• Manual processes held together by spreadsheets and Slack messages
• Operators forced to make decisions with partial information

Despite the risk, no one was building real infrastructure to solve this properly.

Most tools were built for accountants, not operators. Others offered dashboards that sat on top of broken pipes, without addressing the underlying reconciliation problem.

Why we built Rexi

We built Rexi because we wanted the system we never had.

Rexi is an AI-native system of record for fintech reconciliation. It helps teams track, match, and understand every inflow and outflow across banks, processors, partners, and accounts — in one place.

It’s built for operators who need to move fast without gambling on the backend.

We don’t believe reconciliation should be a department.
It should be infrastructure.

Something that runs quietly in the background — and gives you confidence when things don’t go as planned.

Focus matters

Rexi is not a generic workflow tool.
It’s not a dashboard bolted onto an ERP or a ledger.

It’s a purpose-built reconciliation platform for fintechs, designed for the complexity of modern financial ecosystems. We’re vertical-specific, operator-first, and built for real production environments.

That focus matters.

If this sounds familiar

If you’ve ever had that sinking feeling that something is off — and you can’t explain why — you already understand the problem we’re trying to solve.

That’s why we’re building Rexi.