DuBois.sg — Card Platform Technology & Software Development

01 / Services

Engineering services for card platform businesses.

We are a technology partner, not a card platform. We build, connect and maintain the software that powers our clients' card platforms, while they run their own programmes with their licensed partners.

◇Your businessRequirements & roadmap

DuBois.sg engineeringDesign · Build · Integrate · Support

▭Your card platformOperated by you & your partners

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Software development

Custom platform software built to your specification: back-end services, admin consoles, cardholder-facing apps and internal tools.

⊞

System integration

Connecting new and existing systems — processors, core ledgers, CRM, identity verification and reporting — into one working whole.

⇄

API integration

Designing, building and connecting REST APIs and webhooks between your platform and the third-party services it relies on.

⚙

Technical support

Ongoing maintenance, monitoring, troubleshooting and enhancements to keep your systems stable as your business grows.

02 / Solution areas

Technology for the card platforms our clients run.

We build and integrate software for three types of card platform. Our clients own and operate the platform; we provide the technology underneath it.

Virtual card platforms

Software modules for platforms that offer virtual cards for online spending, subscriptions and in-app payments.

Card request and provisioning workflows
Spending limit and control rule engines
Secure card-detail display components

Physical card platforms

Systems that support the physical card lifecycle, connected to the card production and fulfilment partners our clients choose.

Card order, shipping status and activation flows
PIN, freeze and replacement management
Integration with card design and production vendors

Corporate card management platforms

Enterprise software that helps companies manage employee cards, budgets, approvals and expense data.

Team, role and approval management
Budget and policy configuration
Reporting and accounting system exports

We work with Card programme operators Fintech companies Enterprises Digital asset & wallet platforms

03 / Capabilities

The building blocks we engineer for card platforms.

Each capability can be delivered as part of a complete platform build or as a stand-alone module integrated into your existing systems.

▭

Card & programme management

Modules for card products and programme configuration, instant virtual card provisioning, and the physical card lifecycle: production orders, delivery tracking, activation and PIN management.

⚡

Real-time authorisation services

Authorisation handlers that check balances, limits and merchant rules the moment a card is used, and return a decision to your processor within its required time window.

▤

Ledger & reconciliation

Double-entry ledger design for balances, fees and FX adjustments, plus automated matching of settlement files against your own records.

◎

Compliance workflow integration

Configurable onboarding, identity verification and transaction screening workflows, connected to the KYC, KYB and risk providers you select.

⇄

Wallet & account integration

Connecting card balances to the account, wallet or custody systems you and your partners operate, with clear records of every funding movement.

▯

Apps, consoles & mobile wallets

Branded cardholder web and mobile apps, multi-tenant admin consoles, and integration with mobile wallet provisioning flows supported by your processor.

04 / Deep dive

Real-time authorisation, engineered carefully.

The authorisation path is the most time-sensitive part of any card platform. We design it so that each decision is fast, consistent and fully traceable in your ledger.

Rule checks by merchant category, region, channel and limit
Idempotent handling of pre-authorisations, partial captures, reversals and refunds
Atomic balance holds recorded in a double-entry ledger
Signed webhooks and full event logs for audit and support

Example authorisation flowIllustrative

01
Card used
A cardholder pays online, in store or with a mobile wallet; the processor sends an authorisation request.
02
Rules & risk checks
Your platform checks card status, limits, merchant rules and any FX conversion.
03
Ledger hold
The amount is held atomically and written to the ledger.
04
Decision returned
Approve or decline is sent back, and the cardholder is notified.

05 / Engagement models

Three ways to work with us.

Whether you are starting from scratch or extending a product that is already live, we shape the engagement around your team and roadmap.

Full build

Complete platform development

For businesses that need the whole stack. We develop a card management platform under your brand, from back-end services to cardholder apps and admin console.

Your brand, domain and visual identity
Cardholder web and mobile apps
Admin console with roles and reporting
Deployment to your cloud environment

Modules & APIs

Integration into your product

For teams with an existing app or platform. We build and integrate the specific modules and APIs you need, so card features fit into the experience you already offer.

Card, limit and lifecycle APIs
Authorisation and webhook services
Reconciliation and reporting exports
Joint testing with your engineers

Support

Maintenance & technical support

For platforms already in production. We take on ongoing maintenance, monitoring and improvements, whether or not we built the original system.

Bug fixing and troubleshooting
Performance and security improvements
New features and integrations
Technical documentation and handover

06 / How we work

From requirements to a running system.

A clear engagement process, with your business, product and technical teams involved at every stage.

01
Discovery
We map your business goals, existing systems, partners and technical constraints.
02
Architecture & design
We propose a system design, integration plan and delivery milestones for you to review.
03
Build & integrate
We develop in iterations, connect third-party APIs and test in staging environments.
04
Launch & support
We support go-live, then provide maintenance, monitoring and continued development.

07 / Engineering focus

Software infrastructure built to last.

Card management systems need to be efficient, scalable and dependable. These principles guide everything we deliver.

Scalability

Service architectures designed to handle growing users, cards and transaction volumes.

Security engineering

Encryption in transit and at rest, role-based access, audit logging and secure handling of sensitive data.

Maintainability

Clean, documented and tested code that your team, or ours, can extend with confidence.

Reliability

Monitoring, alerting and well-defined deployment processes to keep systems available.

DuBois.sg is a technology and software development company. We do not issue cards, operate card programmes or hold client funds. Card issuance and related regulated services are provided by our clients and their licensed partners.

08 / API integration

Clean APIs that connect your platform.

We design and implement the APIs and webhooks that link your card platform with processors, identity verification, internal systems and client applications.

RESTful endpoints with JSON payloads
Webhook design for card and account events
Sandbox simulators for card use, reversals, refunds and disputes
Idempotent requests, signed callbacks and clear documentation
Secure card-detail display components that keep full card numbers off your servers

POST /v1/cards

// Illustrative example of a client API we might build
curl -X POST https://api.example.com/v1/cards \
  -H "Authorization: Bearer $API_KEY" \
  -H "Idempotency-Key: 7f3c…" \
  -d '{
    "cardholder_id": "ch_123",
    "type": "virtual",
    "currency": "USD",
    "limits": { "daily": 1000 }
  }'

// → 201 Created
{ "id": "card_8KQ…", "status": "active" }

09 / FAQ

Common questions.

Does DuBois.sg issue cards or hold funds?

No. DuBois.sg is a technology and software development company. We do not issue cards, operate card programmes or hold client funds. Card issuance and related regulated services are provided by our clients and their licensed partners.

Who operates the platform we build?

You do. We design, develop and integrate the software; your business and your partners run the card programme and its day-to-day operations.

Can you work with our existing systems and providers?

Yes. System and API integration is a core part of our work. We connect to the processors, identity verification, wallet, accounting and internal systems you already use or choose.

Can you take over support for a platform someone else built?

Yes. We start with a technical review of the existing code and infrastructure, then agree a maintenance and improvement plan with you.

What do you need from us to get started?

A short description of your business, the card types and regions you plan to support, your existing systems and partners, and your target timeline. We use this to prepare a discovery session.

10 / About

A technology company within the DuBois group.

DuBois.sg is an IT software development company specialising in card platform technology and enterprise software solutions. We provide software development, system integration, API integration and technical support for virtual card, physical card and corporate card management platforms.

We focus on technology development and software infrastructure, helping businesses build, manage and maintain efficient and scalable card management systems.

Visit DuBois Gold →

11 / Contact

Let's talk about your project.

Tell us about your platform and what you need to build, integrate or support. Our team will get back to you.

Email: info@dubois.sg

We build the technology behind card platforms.