Digital banking & neobanks
Core banking integrations, account opening, cards and money movement. We launch compliant banking MVPs and grow them into multi-product platforms.
Fintech product engineering · New York & London
We build fintech products that actually ship.
X-Latency is a focused product studio for banking, payments, trading and lending. We take ambiguous regulated problems and turn them into live, compliant products — fast enough to matter, solid enough to scale.
Trusted by neobanks, payment processors and capital-markets teams across the US & EU.
0yrs
Building fintech, full-time
0+
Products shipped to production
$0M+
Processed through systems we built
0
Specialists — engineering, design, compliance
What we do
Regulated products, end to end.
We work where money moves and the rules are strict. Six practices, one team — so your payments, ledger, risk and UX are designed to fit together from day one.
Payments & wallets
Card acquiring, ACH/SEPA, stablecoin rails and wallets. We build payment APIs and double-entry ledgers that reconcile to the cent at scale.
Trading & capital markets
Order management, market-data feeds and low-latency trading UX for retail and B2B. Real-time, resilient, and built to pass an audit.
Lending & credit scoring
Origination, underwriting and decisioning. We ship scoring engines and BNPL/invoice-financing flows that approve good borrowers and reject the rest.
Compliance, KYC & AML
Onboarding, identity verification, sanctions screening and transaction monitoring. Friction where it protects you, none where it doesn't.
Data & analytics
Event pipelines, financial reporting and risk dashboards. We turn raw transactional data into the metrics your board and regulators ask for.
Selected work
Case studies, with numbers.
A sample of products we designed and engineered. Names are anonymized under NDA; the architectures, stacks and outcomes are real to the type of work we do.
Digital banking · EU
Lumen — a consumer neobank MVP in 14 weeks
Challenge. A founding team had an EMI license in progress but no product. They needed a launchable banking app — accounts, cards and KYC — before their next funding round.
What we built. A mobile banking app and admin console on top of a BaaS provider: onboarding, IBAN accounts, virtual & physical cards, and a double-entry ledger for internal balances.
- 90 sec onboarding, down from a 9-minute manual flow
- 12k users in the first 8 weeks after launch
- Seed round closed on the back of a live demo
- React Native
- Kotlin
- PostgreSQL
- AWS
- Onfido
Payments · Crypto rails
Settle — a stablecoin payments API for marketplaces
Challenge. A cross-border marketplace was losing 4–6% to FX and card fees and waiting days for settlement to vendors in three regions.
What we built. A REST + webhook payments API bridging fiat on/off-ramps and USDC, with an idempotent ledger, automated treasury sweeps and per-vendor payout rules.
- $40M processed in the first quarter live
- ~30s settlement vs. 2–3 business days
- -78% cross-border transfer cost per payout
- Go
- gRPC
- PostgreSQL
- Kafka
- Circle API
Lending · B2B
Bridge — an invoice-financing platform for SMEs
Challenge. A specialty lender approved invoice advances by hand in spreadsheets. Decisions took days and risk was inconsistent between analysts.
What we built. An origination portal plus a decisioning engine that pulls accounting data, scores invoices, sets advance rates and routes edge cases to a human.
- 4 hrs average decision, down from 3 days
- +38% approved volume at the same default rate
- -1.9pp loss rate after the first 6 months
- TypeScript
- Node.js
- Python
- XGBoost
- GCP
Trading · Mobile
Vantage — a retail trading app for an EU broker
Challenge. An established broker's web platform felt dated to a younger audience. They were losing first-time investors at sign-up and first trade.
What we built. A mobile-first trading app with streaming quotes, fractional orders, watchlists and a fast, transparent order ticket — wired to the broker's existing OMS.
- 4.8★ App Store rating across 6k+ reviews
- +2.3× first-trade conversion vs. the old web flow
- < 120ms median quote-to-screen latency
- Swift
- Kotlin
- WebSocket
- Redis
- FIX
Compliance · KYC/AML
Sentinel — onboarding & transaction monitoring
Challenge. A payments firm's manual review queue couldn't keep up. False positives buried real alerts and onboarding drop-off was high.
What we built. A KYC onboarding flow with document + biometric checks, sanctions/PEP screening, and a rules + ML monitoring engine feeding a triage case manager.
- -64% false-positive alerts on day one
- 3.2× faster analyst case throughput
- 98.6% straight-through onboarding pass rate
- Java
- Spring
- Kafka
- Elasticsearch
- ComplyAdvantage
Data & analytics · SaaS
Atlas — a real-time finance & risk dashboard
Challenge. A growing wallet provider closed its books with a patchwork of exports. Leadership had no live view of float, exposure or unit economics.
What we built. An event pipeline over the production ledger feeding a metrics layer and dashboards: float, settlement risk, cohort revenue and regulatory reporting.
- Real-time float & exposure, was T+1 at best
- -3 days off the monthly close cycle
- 1 source of truth for board & auditors
- Python
- dbt
- Snowflake
- Kafka
- Grafana
How we work
A process built for regulated speed.
Small senior team, short feedback loops, compliance in the room from week one. No hand-offs to a back office you never meet.
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01
Discovery
We map the product, the money flows and the regulatory perimeter. You leave with a scoped plan, risks named, and a fixed-price first milestone.
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02
Design
Flows, UI and the data/ledger model designed together. We prototype the hard screens early — onboarding, money movement, edge cases.
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03
Build
Two-week increments, demoable every Friday. Tests, CI/CD and audit logging are part of the definition of done — not a later phase.
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04
Launch
Pen-tested, load-tested, and shipped behind feature flags. We support go-live in production and stand up monitoring and on-call.
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05
Scale
We stay on to harden, optimize cost and add the next products — or hand a clean codebase to your in-house team with full docs.
Expertise
The stack we ship with.
Boring-on-purpose where it counts, modern where it pays off. We choose tools that a regulator, an auditor and your future CTO will all be happy to inherit.
GoJava · SpringKotlin
TypeScriptNode.jsPython
ReactReact NativeSwift
PostgreSQLKafkaRedis
gRPCKubernetesAWS
GCPTerraformSnowflake
dbtFIXISO 20022
PCI DSSSOC 2PSD2
The people
Fourteen specialists. No bench, no juniors learning on your dime.
Engineering, product design and compliance under one roof across New York and London. Meet a few of the people who'll be on your project.
EM
Elena Marsh
Founder & CEOEx-payments PM. 12 years across acquiring and core banking; keeps every project honest about scope and risk.
DR
Daniel Roth
CTODistributed-systems engineer. Built ledgers and settlement engines processing nine figures a month.
PK
Priya Kapoor
Head of Product DesignTurns regulated complexity into flows people finish. Obsessed with onboarding and the money-movement screen.
MV
Marco Vidal
Principal Engineer, PaymentsLives in idempotency keys and reconciliation. If money moves, Marco makes sure it adds up.
SO
Sara Olsen
Head of Compliance & RiskFormer AML officer. Translates regulation into product requirements engineers can actually build.
TN
Theo Nakamura
Engineering Lead, MobileShipped trading and banking apps to millions of installs. Cares about latency you can feel in the thumb.
In their words
Teams we've shipped with.
X-Latency shipped our neobank MVP in a quarter and it didn't fall over on launch day. They understood the license constraints better than some of our advisors.
The ledger they built reconciles to the cent across three currencies. Our auditors asked who built it — that's the highest compliment I can give an engineering team.
We came in with a vague idea and a deadline. They pushed back where it mattered, agreed where we were right, and our analysts now decide in hours instead of days.
Start a project
Tell us what you're building.
Whether it's a banking MVP, a payments rail or a scoring engine, we'll come back within two business days with honest feedback and a realistic plan — not a sales deck.