Fintech Software Development Company

Fintech Doesn’t Forgive Bad Architecture. Neither Do Regulators.

Global fintech revenue hit $650 billion in 2025, growing 21% year over year (McKinsey/QED, April 2026). VC investment rebounded to $116 billion across 4,719 deals (KPMG Pulse of Fintech). The money is real. The regulatory bar is higher than it’s ever been.

PCI DSS 4.0 is now baseline. The EU AI Act classifies credit scoring as high-risk, with full obligations from August 2026. PSD3 and the Payment Services Regulation were politically agreed in November 2025 and will apply by 2028. Every fintech product built today will need to comply with rules that didn’t exist when the project started.

EltexSoft is a boutique engineering studio. 35-50 senior engineers. We’ve been building fintech software for 11 years. Our clients include a $190M-funded Canadian corporate card platform, a $30M-funded marketplace processing 200,000+ monthly transactions, and a passenger rights portal that has recovered over €100M through automated payouts. We understand what it takes to ship financial software that passes audits, not just demos.

What We Build

Payment Platforms and Card Programs

Card acquiring, card issuing, wallet and ledger systems, multi-currency settlement, payout orchestration. We integrate with Stripe, Adyen, Checkout.com, Visa, and Mastercard. We architect for PCI DSS 4.0 scope reduction through tokenization, segmented cardholder data environments, and zero-trust network design. The cheapest PCI audit is the one with the smallest scope.

For Float Financial, we worked on the engineering behind corporate card programs (CAD and USD), high-yield business accounts, and expense management serving 6,000+ Canadian businesses. Float is a PCI-certified third-party service provider backed by Goldman Sachs, OMERS Ventures, and Tiger Global.

Neobanking and Digital Finance

End-to-end consumer or SMB digital banking: onboarding with KYC/KYB verification, core ledger, virtual and physical card programs, high-yield accounts, bill pay, FX, AP automation, transaction notifications, and back-office tooling.

The engineering challenge isn’t any single feature. It’s the interaction between all of them. A bill payment triggers a ledger entry, a card authorization, a notification, a receipt capture, and a reconciliation event. Miss any one and the books don’t close. Our engineers build these systems with double-entry discipline because they’ve seen what happens when you don’t.

Marketplace Payments

Split payments across hundreds of sellers, multi-vendor payouts, escrow, dispute handling, and multi-PSP failover. This is the architecture we built with Nautical Commerce, a $30M-funded multi-vendor marketplace platform processing 200,000+ monthly transactions with payments orchestration across vendor splits.

The hard problem in marketplace payments is idempotency. A webhook from Stripe fires twice. A payout to a seller fails and retries. A buyer disputes a charge that’s already been split across three vendors. Every one of these scenarios needs a deterministic answer, not a race condition. That’s the engineering discipline we bring.

Claims, Recovery, and Automated Payouts

MyFlyRight is a German passenger rights portal that has recovered over €100M for European air travelers under EU Regulation 261/2004. We’ve been their engineering partner for 10 years. The platform handles claim assessment, automated airline settlement, court integration, and an instant-pay product that delivers full compensation within 24 hours.

This is regulated, multi-jurisdiction, money-movement software with the same engineering disciplines as building a payouts platform. The system has been used in 5,000+ court cases and was party to European Court of Justice rulings C-157/22 and C-158/22 against TAP Portugal.

Lending and Credit Platforms

Loan origination, underwriting workflows, alternative-data credit models, servicing, and collections. The EU AI Act classifies AI-based credit scoring as high-risk under Annex III, with full obligations from August 2026, including documented risk management, data governance, bias testing, transparency requirements, and conformity assessment.

We build lending systems with the documentation layer from day one, not as a compliance retrofit. Model explainability, human-oversight mechanisms, and audit trails are architectural decisions, not bolted-on features.

Fraud, AML, and Transaction Monitoring

Real-time scoring pipelines built with Python/FastAPI and Kafka. Sanctions screening integration with ComplyAdvantage and similar providers. Case management dashboards, suspicious-activity reporting workflows, and rule engines that adapt to evolving threat patterns.

Fraud detection AI is exempted from the EU AI Act’s Annex III high-risk classification, but it still triggers GDPR Article 22 (automated individual decision-making) and potentially Article 9 (special category data) obligations. We build with both frameworks in mind.

The Tech Stack

Fintech in 2026 is polyglot by necessity. No single language handles every constraint.

Backend: Java and Spring Boot for compliance-heavy core systems where audit trails and transaction integrity are non-negotiable. Node.js for real-time, event-driven APIs. Python with FastAPI for ML serving (fraud scoring, credit models, document extraction). Go for high-throughput ledger and payment paths where microseconds matter.

Data: PostgreSQL as the system of record. TimescaleDB for transaction-history analytics. Kafka for event streaming. Redis for caching, rate limiting, and idempotency keys. This is the same stack the Federal Reserve’s FedNow instant payment system was built to support. The Fed raised the per-transaction limit to $10 million in November 2025 because demand for real-time settlement keeps growing.

Cloud and DevOps: AWS with PCI-ready landing zones (preferred), GCP and Azure on request. Kubernetes for service isolation and PCI scope reduction. Terraform for infrastructure-as-code and audit trails. GitHub Actions for CI/CD with mandatory code review gates.

Payments and Identity: Stripe, Adyen, Checkout.com, Plaid, Tink, TrueLayer for open banking, Onfido and Sumsub for KYC, ComplyAdvantage for AML screening, Marqeta and Galileo for card issuing.

Security: OAuth 2.0/OpenID Connect, FAPI for open banking, mTLS service-to-service, AES-256 at rest, TLS 1.3 in transit, HSM-backed key management.

Why Compliance Is the Moat

The regulatory map for fintech in 2026 is the densest it has ever been. The EU is setting the pace, and every other jurisdiction is following.

PCI DSS 4.0. Baseline for any system that touches cardholder data. We architect for scope reduction, not maximum control sprawl.

PSD2 / PSD3 / PSR. PSD2 remains in force. PSD3 and the Payment Services Regulation were politically agreed on November 27, 2025. The Council published final compromise texts in April 2026, with Official Journal publication expected mid-2026 and application around Q2/Q3 2028. The headline changes: payee-name/IBAN verification on all credit transfers, expanded PSP liability for authorized push-payment fraud, and merger of the E-Money Directive into a single payment-institution regime.

EU AI Act. Credit scoring and life/health insurance pricing are classified as high-risk under Annex III. Full obligations apply from August 2, 2026. Non-compliance fines reach €35 million or 7% of global turnover.

EU Instant Payments Regulation. Requires 24/7/365 instant euro transfers settled in under 10 seconds, with Verification of Payee. A hard architectural requirement for any EU-facing payments product.

GDPR, DORA, KYC/AML. All active, all applicable, all requiring engineering discipline. An EU-headquartered partner handles these natively.

What It Costs

Fintech development pricing in 2026 follows a clear pattern across multiple vendor benchmarks:

Focused MVP (one core money-movement journey): $40K-$150K, 4-6 months.

Feature-complete platform (neobank, lending, marketplace payments): $150K-$400K, 6-12 months.

Full-scale multi-jurisdiction platform: $300K-$1M+, 12-24 months.

Compliance overhead adds 15-20% to any fintech build: KYC integration, PCI scope management, audit trail infrastructure, regulatory documentation.

Maintenance runs 15-25% of build cost annually. We handle it inside the same retained team.

At EltexSoft’s rates ($50-99/hr for senior engineers), a 4-person fintech team costs $25K-$45K per month. Compare that to US-onshore fintech specialists at $100-$250/hr, or Indian rates at $20-$50/hr where PCI-DSS production experience is rare at the junior level.

Why Lisbon + Ukraine for Fintech

Lisbon is a serious fintech jurisdiction. Portuguese fintechs have attracted €1.19 billion in cumulative investment (Portugal Fintech/KPMG Report 2025). 64.7% are headquartered in Lisbon. 74% already integrate AI into their products. The city hosts Fintech House (110+ companies) and Web Summit. Portugal ranks 5th globally for engineering degree concentration (OECD).

An EU headquarters gives your project native GDPR controller status, PSD2/PSD3 regulatory proximity, EU AI Act conformity-assessment readiness, and euro-denominated invoicing that simplifies procurement for European banks and PSPs.

Ukraine provides the engineering depth. 300,000+ software developers. 23,000+ tech graduates annually. ICT exports exceeded $6 billion in 2024, growing 54.5% from 2019 to 2024 despite the war. Ukrainian engineers have deep fintech specialization. The country’s IT sector serves Revolut, Wise, and dozens of other European fintech companies.

Our team has maintained uninterrupted delivery through distributed infrastructure, and our EU operational headquarters provides the contractual and jurisdictional stability fintech clients require.

Who We Are

EltexSoft is a boutique fintech software development company. 35-50 senior engineers. Headquartered in Lisbon, Portugal. Engineering team in Ukraine. Founded in 2015. 5.0 Clutch rating across 30+ verified reviews. 200+ five-star Upwork reviews. Top Rated Plus and Expert-Vetted agency status (top 1%). Average client engagement: 3+ years.

We work across FinTech, LegalTech, eCommerce, EdTech, and AI. Our fintech clients include Float Financial, Nautical Commerce, and MyFlyRight. Our staffing models include dedicated teams, staff augmentation, and outsourced delivery.

The team that builds your MVP is the team that maintains it three years later. That matters in fintech, where a scheme rule update from Visa or a regulatory change from the EBA can require code changes in production within weeks.

30-minute technical discovery call with a senior engineer. Bring your architecture questions. We’ll tell you what we’d build and what we wouldn’t.

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