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Fintech verticals
Software built for how each corner of finance actually moves money
Banking, payments, trading, insurance, and lending share a name — financial services — and almost nothing else about how they're built. Each has its own systems of record, its own regulator, and its own failure modes.
Banking
Digital account opening, member and customer portals, and reconciliation that has to match a core ledger penny for penny. Most banking work is integration — the core system carries the ledger of record, and the build has to read and write around it correctly, not replace it.
Payments
Payment initiation, card issuing, ACH and wire rails, and the settlement and reversal logic that has to hold up when a transaction fails halfway through. Idempotency and reconciliation are what separate a payments system that survives an audit from one that doesn't.
Insurance
Quoting engines, claims intake, and underwriting workflows that encode rules varying by state and product line. The hard part is rarely the interface — it's a rules engine an underwriter can update without waiting on a deploy.
Exchanges and trading
Order books, matching logic, charting, and market-data pipelines where latency and correctness both matter and neither gets traded off casually. We rebuilt an automated trading platform from the ground up — charting, backtesting, broker connections, and a strategy marketplace — see the case study below.
Lending
Origination workflows, credit-decisioning integrations, and the KYC/AML checks that have to clear before money moves, with an audit trail that shows exactly what was checked and when.
Financial data and analytics
Aggregation, reporting, and dashboards that turn transaction volume into something a risk officer or a CFO can act on — usually built on a data warehouse that has to reconcile against the ledger it's summarizing, not drift from it.
Compliance and security
The regulatory layer that has to be designed in, not added before launch
None of the following is optional, and none of it is cheap to retrofit. The architecture decisions below are the ones that are far harder to unwind after a system is live than before the first line of code is written.
PCI DSS
Any system that touches cardholder data has to be architected around PCI DSS scope from day one — tokenizing card data at the edge and using a processor's vault instead of storing card numbers yourself wherever that's an option. Designing to shrink PCI scope is almost always cheaper than building the controls a wider scope requires.
SOC 2
SOC 2 is an attestation about your organization's controls, performed by your own auditor — not a checkbox a vendor adds to software. What we build is the access logging, change management, and encryption a SOC 2 audit actually examines; the attestation itself belongs to you.
KYC/AML
Identity verification, sanctions screening, and transaction monitoring usually run through a specialized vendor rather than being built from scratch. The engineering work is making sure a failed or pending check blocks the right downstream action instead of silently letting it through.
Encryption and data residency
Financial data is encrypted at rest and in transit as a baseline, and some institutions add data-residency rules that decide which cloud regions are on the table before any infrastructure code gets written.
Audit logging
Every action that touches money or personal financial data needs a log entry — who, what, when — written to a store the application itself can't quietly rewrite. Retrofitting this after launch means replaying history you don't have; it has to exist from the first transaction.
Non-production environments
Test and staging environments run on synthetic or masked data, not a copy of production account numbers. A surprising number of fintech data exposures trace back to a staging database holding real customer records, and it's one of the cheapest problems to avoid.
What's involved
Fintech engagement types
What moves the scope here is not feature count — it's how many outside systems the build has to reconcile against: a core banking platform, a payment processor, a KYC vendor, a market-data feed. Each one adds its own failure modes and its own audit surface.
| Engagement | Commitment | Timeline | What's included |
|---|---|---|---|
| Compliance & architecture audit | Fixed scope | 1 – 3 weeks | PCI/SOC 2 scope review, data-flow mapping, and a prioritized list of what has to change before a build starts. |
| Payments or core banking integration | Fixed scope | 6 – 12 weeks | Integration with a payment processor, card issuer, or core banking API, including reconciliation logic and transaction failure handling. |
| KYC/AML and onboarding workflow | Fixed scope | 4 – 10 weeks | Identity verification and sanctions-screening integration, decisioning logic, and the audit trail regulators expect to see. |
| Trading or market-data platform | Fixed scope | 10 – 20 weeks | Charting, order handling, backtesting, and broker connections, built for the latency and correctness a trading product needs. |
| Ongoing compliance & platform support | Ongoing retainer | Ongoing | Standing ownership of the platform through regulatory changes, security patching, and audit season. |
Ranges assume US-based senior engineers and include the compliance and audit-trail work a cheaper quote often strips out. The audit exists as its own first step because it's the fastest way to find out which of these categories a build actually falls into before anyone commits to the rest.
Build vs. integrate
Where a fintech build is really an integration project
Most of the engineering risk in fintech isn't in code you write from scratch — it's in the systems you have to work around correctly.
Payment processing
Building your own card-network integration from scratch is rarely the right call; a processor's vault and tokenization API removes most of your PCI scope in exchange for a transaction fee you're already budgeting for. The real work is the reconciliation and failure handling around it, not the card rails themselves.
Core banking
Almost no institution replaces its core system to ship a new feature. The build works through whatever interface the core actually exposes — a modern API, a file-based batch interface, or something in between — and that interface, not the feature list, is usually what sets the real timeline.
Identity and KYC
Sanctions screening, document verification, and ongoing monitoring are specialized problems with vendors who do them full time. The integration work is making the failed and pending states behave correctly inside your workflow, not rebuilding the screening itself.
Ledger design
A financial system's ledger is the one part worth building carefully and rarely worth handing to a generic accounting library. Double-entry, immutable, and reconcilable against source-of-truth systems is the standard to hold it to, even in a product that doesn't look like accounting software on the surface.
Real-time vs. batch settlement
Not every payment needs to settle in real time, and treating all of them as if they do adds complexity a batch settlement window would have avoided. Decide per payment type which one you actually need before designing the pipeline, not after.
Blockchain and smart contracts
Worth it when the product's core value is a shared, trustless ledger between parties who don't otherwise trust each other — cross-border settlement, tokenized assets, a decentralized marketplace. The operational and audit complexity of a blockchain layer is real, and it earns its place on the strength of that use case, not as a technology choice layered onto a product a normal database would serve just as well.
What we've built
An algorithmic trading platform, rebuilt from the ground up
One of the more complete fintech builds in our case studies: a full rebuild of an existing trading platform that had been a market leader before newer entrants caught up, done as a ground-up replacement rather than a patch. It's a useful reference for what a serious trading product actually needs.
Charting built to be read fast
Candlestick, line, and bar charts with real-time and historical trends, moving averages, Bollinger Bands, RSI and stochastic oscillators, plus a colour-coded table summarizing suggested buy and sell actions.
Automated trading
Traders set the criteria they consider favourable, and the platform monitors the market and places buy or sell orders automatically when those criteria are met.
Backtesting
Strategies tested without risking capital, against a results screen traders tailor to their own algorithms and the fields they care about.
Broker connections
A base of trusted brokers users can add to a personal list, with connection management and unlimited trade placement.
A strategy marketplace
Once a trader perfects a strategy, they can sell it to other users on the platform — a second product built on top of the trading engine itself.
Follow top traders
Users who want guidance can follow professional traders, watch their activity, and copy the steps they take.
The build also included social login, customisable dashboards, analytics tools, and real-time notifications — the surrounding product work a trading platform needs beyond the trading engine itself. Our fintech work has also included engagements with institutions such as Bank of America Merrill Lynch and UBS Wealth Management.
Regulatory differences by vertical
The rules that actually shape a fintech architecture, by vertical
Financial regulation isn't one regime. Building against the wrong one, or against a generic idea of "fintech compliance," is a rebuild waiting to happen.
Banking & credit unions
BSA/AML and FFIEC guidance shape everything from onboarding to transaction monitoring, and a core banking relationship means the architecture has to fit inside whatever interface that provider actually exposes.
Payments
PCI DSS governs anything that touches cardholder data, and NACHA operating rules govern ACH transfers specifically — both matter if a product moves money by card and by bank transfer.
Insurance
Insurance regulation is set state by state in the US, which means a rules engine has to encode dozens of different rate and disclosure regimes rather than one national standard — and that variability belongs in configuration, not in application code.
Trading & exchanges
Broker-dealers and trading venues answer to FINRA and SEC recordkeeping and best-execution requirements, which shape how long data has to be retained and how order handling has to be logged, not just how a chart looks.
Lending
Fair-lending and disclosure rules constrain how a credit-decisioning workflow can use data and what it has to explain to a rejected applicant — an architecture question as much as a legal one.
Related
Related services
What fintech builds usually connect to.
Questions
Common questions about fintech development
What teams ask before a first call.
Two things: the regulatory constraint and the integration surface. A fintech product usually has to satisfy PCI DSS, SOC 2 controls, or KYC/AML requirements from the start, and it almost always has to work correctly alongside a core banking platform, a payment processor, or an identity-verification vendor you're not replacing.
That combination means the architecture decisions — how data is tokenized, how a ledger reconciles, what gets logged — carry more weight earlier than they would on a typical product, because unwinding them after launch is expensive and sometimes not possible without a rebuild.
We build the architecture those frameworks require — tokenization and reduced PCI scope, access logging, change management, and encryption at rest and in transit. PCI DSS and SOC 2 are attestations performed by your own assessor or auditor against your organization, not a certification DEV.co holds or can issue on a vendor's behalf.
What we can do is design and build so that attestation is straightforward when you go through it, rather than discovering gaps during the audit itself.
Yes — that's most of what a banking or payments build actually is. The work runs through whatever interface your core or processor exposes, whether that's a modern API or a file-based batch interface, and the integration has to handle reconciliation and failure states correctly, not just the happy path.
We'll tell you early if what you're describing is closer to a core replacement than an integration, because those are very different projects with very different timelines.
No, and we'd advise against it. Identity verification, sanctions screening, and ongoing transaction monitoring are specialized problems with vendors who run them full time; building that in-house is a multi-year undertaking most product teams shouldn't take on.
The engineering work is the integration — making sure a failed check blocks the right action, a pending check doesn't silently pass, and the audit trail shows exactly what ran and when.
Yes, when the use case actually calls for a shared, trustless ledger — cross-border settlement, tokenized assets, or a marketplace between parties who don't otherwise trust each other. Those are real, specific situations where the operational overhead of a blockchain layer pays for itself.
Where the same problem is better served by a normal database, we'll design it that way instead. The decision is about the use case, not about whether blockchain is the more exciting technology to build.
A full rebuild of an existing trading platform: charting with technical indicators, automated trading against trader-set criteria, backtesting, broker connections, a marketplace for selling strategies, and the ability to follow and copy professional traders. It also included social login, customisable dashboards, and real-time notifications.
It's documented in more detail on our case studies page, including the broker-connection and backtesting mechanics.
You do. Source code lives in a repository under your organization from the first commit, and cloud infrastructure runs in your own account. That's the only arrangement that doesn't lock a regulated financial product to a single vendor for its next audit, its next feature, or its next migration.
Non-production environments run on synthetic or masked data, not copies of production account or transaction records. Access to anything resembling real financial data is restricted and logged, and encryption at rest and in transit is a baseline across every environment, not just production.
This is a cheap discipline to maintain from day one and an expensive one to retrofit after a staging database has been passed around a team for a year.