Arc Finlabs markarc finlabsContact

Software engineering and IT consultancy for business clients.

Arc Finlabs Limited builds the software business clients run on — including specialist work for the payments and banking sector, and for clients building smart-contract and on-chain infrastructure. We build; our clients hold the licences and operate the services.

Arc Finlabs Limited is not authorised or regulated by the Financial Conduct Authority and does not handle client funds.

What we dohello@arcfinlabs.co.uk

Four tracks of work. One bar for the work.

Engagements where the cost of a wrong technical decision is high.

  1. Web applications and internal tools

    Custom web applications, internal tools, and admin dashboards.

    The day-to-day software business clients run their operations on.

    Scope
    • Custom web applications on modern React and TypeScript stacks
    • Internal tools and admin dashboards for operations teams
    • Workflow, reporting, and process-automation interfaces
    • Accessibility, responsive design, and long-term maintainability
  2. Backend systems, APIs and data

    Backend engineering, API integrations, and database architecture.

    The services, APIs, and databases that hold the business's record of what happened.

    Scope
    • Backend services in TypeScript, Node.js, and Python
    • API design, third-party integration, and ongoing maintenance
    • Relational database design and query-layer engineering
    • Logging, monitoring, cloud-infrastructure support, and operational visibility
  3. Payments and banking sector

    Specialist engineering for clients in payments and banking.

    Clients in the payments and banking sector hold the authorisations and operate the services; we engineer, integrate, and maintain the systems behind them.

    Scope
    • Card-acquiring and payment-gateway integration work, built into our clients' authorised platforms
    • PCI-DSS-aware application architecture and scope reduction for regulated clients
    • ISO 8583 and ISO 20022 message handling, implemented for licensed operators
    • Reconciliation, dispute, and back-office tooling for our clients' operations teams
  4. Smart contracts and on-chain infrastructure

    Audit-grade smart-contract engineering for client-operated on-chain systems.

    Clients building tokenisation, on-chain settlement, and stablecoin-payment systems deploy and operate their own contracts; the engineering is ours.

    Scope
    • Solidity contract design, implementation, and test coverage for EVM chains
    • Atomic-routing, registry, escrow, and access-control contract patterns
    • Multi-chain deployment and integration work
    • Audit-readiness: NatSpec, threat models, invariant tests

Five principles that hold for every engagement.

  1. Principle

    Specificity.

    We name the standard, the framework, the interface.

  2. Principle

    Composability.

    Small, testable pieces with clear contracts. Fewer frameworks, more primitives.

  3. Principle

    Auditability.

    If a write cannot be reconstructed from the logs, it did not happen.

  4. Principle

    Restraint.

    We ship what the work requires.

  5. Principle

    Verification before claims.

    If it has not been proven, it does not go out.

Business clients that treat software as infrastructure.

Payment institutionsCard acquirersCard issuersPayment gateways and processorsBanks and neobanksCryptoasset firms and on-chain product teamsTokenisation and stablecoin-payment teamsB2B SaaS and operational-software teams

We build the software our clients run on. They hold the authorisations and operate the services.

We take on a small number of engagements at a time.

Email is enough. Tell us who you are and what you are trying to build.

hello@arcfinlabs.co.uk
Email
hello@arcfinlabs.co.uk
Web
arcfinlabs.co.uk
Registered office
167-169 Great Portland Street, 5th Floor, London W1W 5PF
Company number
17057409
Jurisdiction
England and Wales