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Industries /FinTech & Banking

Custom fintech
software development
for banks and banks and startups.

Custom fintech software development for banks, fintech startups, and financial institutions. We build payments, digital banking, lending, and ledger products where audit teams and growth teams both win — auth, reconciliation, and key handling done right the first time. Compliance is non-negotiable; the user experience can't suffer for it.

PCI-DSS scoped SOC 2 baked in p99 < 150ms auth
Why Entalogics for FinTech

Four things every
fintech build actually needs.

A founding-team-grade build for financial software where mistakes cost money — literally. The non-negotiables, in our own words.

Threat-modeling01

Security is the architecture, not a layer.

Key handling, signing flows, and blast-radius limits are decided before the first endpoint is written. In fintech application development, audits become a checkbox, not a fire drill.

Latency02

120ms p99 auth, even on a bad day.

We size the data path for the worst Tuesday afternoon — not the demo. Card auth, ledger reads, fraud scoring all stay under SLA when traffic doubles.

Reconciliation03

Money is right. Always. By design.

Double-entry ledgering, idempotent writes, and end-of-day reconciliation are non-optional. Finance ops never opens a ticket asking why a number doesn't match.

Auditability04

Every change, every actor, on the record.

Tamper-evident logs, signed releases, and reversible deploys. Regulatory compliance evidence your auditor walks through without our help.

What we ship

Six fintech product surfaces.
One quality bar.

The shapes of fintech software development we've shipped most often — from payment processing to digital banking infrastructure — each with the integrations we reach for first.

P01
Payment rails & orchestration
Multi-PSP payment processing: routing, retry logic, dunning, smart-fallback acquirers. Authorization rate up; cost-of-acceptance down.
STRIPEADYENBRAINTREEPAYPAL
P02
KYC / AML pipelines
Document verification, liveness, sanctions screening, transaction monitoring, SLA-bound onboarding — the compliance spine of every fintech app.
JUMIOALLOYPERSONACOMPLYADV
P03
Underwriting & loan origination
Digital lending end to end: scorecards, credit decisioning trees, manual review queues, e-sign, funding orchestration.
PLAIDNOVAFINICITYDOCUSIGN
P04
Trading & portfolio dashboards
Real-time P&L, positions, risk, order tickets for trading and investment platforms. Sub-50ms refresh; FIX gateway when needed.
IEXPOLYGONALPACAFIX
P05
Card issuance, wallets & ledgering
Card program management, virtual + physical cards, digital wallet flows, double-entry ledger, dispute workflow.
MARQETALITHICGALILEOSTRIPE-ISSUE
P06
Digital banking & FinOps reconciliation
Neobank-grade account experiences plus bank-statement matching, settlement files, GL exports — open banking data in, finance-team tooling out.
PLAIDCSVNETSUITEQUICKBOOKSSFTP
The bar

Compliance,
wired into fintech delivery.

The controls we wire into the architecture from week one — not a checklist we hand to legal at the end. Every row below has carried us through an audit.

Tokenisation
PAN replaced at edge; never lands in app tier.
PCI-DSS · SAQ D
Encryption
TLS 1.3 in transit, AES-256 + customer-managed KMS at rest.
PCI · SOC 2
Auth & RBAC
OIDC, MFA, SSO; role boundaries enforced at the database row.
SOC 2 · ISO 27001
Audit logs
Append-only event store; tamper-evident hashes; 7-yr retention.
SOX · SOC 2
Key management
HSM-backed signing for high-value flows; rotation automated.
PCI · NIST 800-57
Data residency
Per-tenant region pinning; encrypted backup replication.
GDPR · DORA
Signature case

A multi-region
card-issuing platform.

A B2B card-issuing platform serving fintech operators in three regions. We came in pre-launch with the architecture in flux, the ledger half-built, and the PCI auditor scheduled.

BEFORE
p99 auth 480ms · ledger drift weekly · PCI scope across 14 services
AFTER
p99 auth 120ms · zero drift · PCI scope reduced to 2 services
p99 card-auth latency120ms
annualised volume$2.4B
PCI controls passed first audit47/47
reconciliation breaks since launch0
Engagement shape

Eight weeks to a
defensible fintech build.

A typical fintech software development engagement, end-to-end. Compliance work runs in parallel from week one — never bolted on at the end.

W01–02
Threat model + ledger sketch
Two senior engineers + Umar in the room. Threat model, data classification, ledger design. Compliance posture decided before any code is written.
W03–05
Core build
Auth flows, ledger writes, payment-rail and open banking integrations. Each sprint ships a testable vertical slice. No stubs that get replaced later.
W05–08
Hardening + scale
Performance, fraud detection rules, dispute workflow, finance-team tooling. Load-tested at 10x expected peak. Runbook drafted alongside the build.
W09+
Audit + handoff
PCI / SOC 2 evidence collected as a side-effect of the build. Code, infra, and runbook handed to your team or kept on retainer — your call.
Stack

Fintech tools we
reach for first.

Picked by problem, not by resume. We're happy to swap into your stack — but on a green-field fintech build, this is the default.

Languages
Go · TypeScript · Rust (signing layer)
Data
Postgres · ClickHouse · Kafka · Temporal
Identity
WorkOS · Auth0 · Cognito · OIDC + SAML
Payments
Stripe · Adyen · Marqeta · Lithic · Plaid
Infra
AWS (VPC-isolated) · GCP · Terraform · Kubernetes
Observability
Datadog · Honeycomb · Grafana · Tempo · OpenTelemetry
Definition

What do fintech software development services cover?

Fintech software development is the engineering of financial products — digital banking platforms, payment processing, digital wallets, lending systems, trading platforms, and the KYC/AML compliance infrastructure underneath them — built to the security and regulatory standards of banks and financial institutions: PCI DSS, SOC 2, ISO 27001, GDPR. It differs from general software development in three ways: money must reconcile to the cent (double-entry ledgers, idempotent writes), every action must be auditable (tamper-evident logs, evidence trails), and integrations run through regulated rails (open banking APIs, card networks, payment gateways). We build all of it with compliance wired in from week one, which is why our builds pass first audit instead of failing their first questionnaire.

FAQ

Sharp questions,
straight answers.

Yes — it's designed in, not added on. The compliance table above is implemented during the build, and the evidence (logs, policies, controls) is collected as a side-effect. Our signature case passed 47/47 PCI controls on the first audit.
By making it architecture, not paperwork. Tokenisation, encryption, RBAC, audit logging, key management, and data residency are wired in from week one against named standards — PCI DSS, SOC 2, ISO 27001, GDPR, and DORA where it applies. Compliance posture is decided in W01, before any code is written.
Yes — it's most of what we do. Stripe, Adyen, Marqeta, Lithic, and Plaid are in our default stack; Jumio, Alloy, and Persona on the KYC side; IEX, Polygon, and FIX for market data. Bank and core-system integrations get contract design, sandbox testing, retry logic, and monitoring — not a hopeful API call.
Yours, gladly. The stack table is our green-field default; on existing fintech products we adopt your languages, infra, and vendors and improve from inside them.
Fixed quote after the W01 threat-model week, when scope is genuinely known. The eight-week shape above is the typical envelope for a first defensible build; bigger scopes get honest timelines, not squeezed ones.
Per-tenant region pinning with encrypted backup replication — GDPR and DORA aligned. Our signature card-issuing platform runs in three regions with zero reconciliation breaks since launch.
Yes. Senior engineers only, no handover to a B-team after the sale. The people in the W01 threat-model room are the people who ship W09.
Founder-direct

Tell us what you're
moving.

Thirty minutes with the founder. We'll bring a senior FinTech lead, the relevant playbook, and a candid read on whether your problem is one we should take.