Banking has a peculiar way of hiding its machinery. The customer sees a balance, a card and perhaps a satisfying little notification when money lands. Behind that calm surface sits a quarrelsome city of ledgers, payment rails, fraud engines, customer records, lending rules, call-centre queues and regulatory reports. A small institution can end up buying twenty systems before it has built one coherent bank. Constantinople, a Sydney company founded by former Westpac executives Macgregor Duncan and Dianne Challenor, has made that sprawl its target.
Its proposition is unusually wide. Constantinople supplies customer apps and APIs, configurable accounts and loans, payment and card capabilities, a real-time data layer, cloud infrastructure, risk controls and the people-and-software workflows that handle operations. The bank keeps its licence, its balance sheet, its brand and its relationship with customers. Constantinople aims to become the operating fabric underneath.
That puts the company in an awkwardly interesting category. It is part enterprise software vendor, part Banking-as-a-Service provider, part systems integrator and part managed operations firm. The founders have used the phrase “Shopify for banks,” but the storefront comparison only goes so far. Shopify does not normally investigate a suspicious transaction at three in the morning or prepare a regulator-ready report. Constantinople says its platform and operators can.
01 / The thesisSell the outcome, not the integration project
Traditional bank technology is assembled in layers. A core system records accounts. Other vendors handle onboarding, cards, payments, digital channels, fraud, communications and reporting. Consultants connect the pieces. Bank employees operate the result. Each handoff adds cost, delay and a fresh opportunity for data to disagree with itself. A shiny mobile app can therefore conceal a decidedly unshiny operating model.
Constantinople’s difference is not that every individual capability is unprecedented. It is that the capabilities arrive pre-integrated and are operated as one service. A client can launch a ready-made, branded mobile and web experience or build its own interface on headless APIs. Underneath, the same platform can configure deposits, payments, cards, mortgages and business loans. It can automate onboarding, monitor fraud, service lending, support customers and manage collections. Justinian, its appropriately imperial banker console, gives staff a shared place to configure products, inspect cases and follow audit trails.
“Banks don’t need to run all of this infrastructure and operational services - they put their customers on our platform and they pay a SaaS fee rather than manage the capabilities themselves.”Macgregor Duncan, Co-Founder and Co-CEO
The commercial logic follows the architecture. Constantinople charges a scalable enterprise platform fee, with managed services folded into the relationship where required. Instead of separate licences and implementation programs, the client buys a working capability. For an embedded-finance brand, that can mean offering accounts and cards inside an existing product while a licensed banking partner and Constantinople handle the regulated machinery. For an established bank, it can mean migrating away from a legacy estate or launching a new proposition alongside it.
02 / Who buys itFour customers, four versions of the same machine
Constantinople’s published client list shows why breadth matters. Great Southern Bank, Australia’s largest customer-owned bank, used the company to develop digital products for small businesses. Its Business+ app brings together accounts, invoicing, direct feeds to MYOB and Xero, and digital applications for vehicle finance. Great Southern Bank says it serves around 420,000 Australians. The point is not that all of them use Constantinople directly; it is that the platform has moved beyond a laboratory deployment into the machinery of a substantial regulated institution.
MYOB presents a different route. Solo Money places a transaction account inside MYOB’s mobile product for sole operators. The user stays in an administrative app, the account comes from Great Southern Bank, and Constantinople helps connect the experience to banking infrastructure. Tyro, known for merchant payments, is using the platform as it expands toward fuller banking services. MoveBank is taking the most comprehensive path: a migration of its retail member base, products and data to a new Constantinople-powered foundation.
These are not four copies of one neobank template. They are a greenfield small-business bank, an embedded account, an expansion by a payments company and a full retail migration. That variety is the sales argument. Constantinople wants one platform to flex across licensed banks, mutuals, credit unions, fintechs and software brands without turning each deployment into bespoke archaeology.
The product catalogue is deliberately mundane in the best banking sense. Deposit products include everyday and savings accounts, term deposits and business accounts. Payments cover real-time, scheduled and bulk transfers, bills and approval controls. Cards can be physical or digital. Lending stretches from personal and vehicle loans to business credit and mortgages, with origination, decisioning, settlement and servicing connected. On the operational side, Constantinople offers onboarding support, disputes, chargebacks, fraud investigation, collections and hardship handling. These are the jobs that determine whether a banking proposition remains a polished prototype or becomes a durable service.
One contract, five layers of bank
Relative bars illustrate platform scope, not revenue or usage.
03 / The hard partBanking punishes the merely impressive demo
A banking platform is judged less by its best day than by its worst. It must reconcile money exactly, preserve a record of every consequential action, survive infrastructure failures and explain decisions to auditors. It must also absorb routine human mess: an onboarding exception, a disputed card purchase, a borrower in hardship. This is where Constantinople’s decision to treat “operations as product” becomes more than a slogan. The interface used by an operator, the queue that routes work and the control that prevents an unsafe action are parts of the same design.
The company describes its architecture as cloud-native, event-driven and API-first. It lists active-active failover, end-to-end encryption, round-the-clock security operations and immutable audit histories among its controls. It also reports ISO 27001 and SOC 2 Type II certification. In risk and compliance, it maps obligations into workflows, uses automated monitoring and keeps human oversight around AI. The practical promise is not autonomous banking. It is faster decisions inside observable guardrails.
That distinction matters because “AI-native” has become inexpensive language. Constantinople is at its most credible when AI disappears into specific work: triaging a fraud alert, searching a customer timeline, routing a support case, checking serviceability or surfacing a control failure. A bank does not need a chatbot with imperial ambitions. It needs fewer manual queues and a clean account of what the machine did.
The valuable AI is not the one that sounds like a banker. It is the one that can help run a bank - and leave an audit trail.YesPress analysis
04 / The marketBetween the core and the customer
Constantinople sits in a crowded supply chain. Temenos, Mambu, Thought Machine, Fiserv and others sell core or account-processing technology. Backbase and digital-banking specialists shape customer channels. Banking-as-a-Service providers connect brands to regulated products. Large integrators make the pieces coexist. Banks can also build more themselves. Constantinople’s answer is to own the seams among those categories, while still partnering where a specialist adds leverage.
The usual purchase
Buy a core, channel software, fraud tools and payment services. Hire an integrator. Staff the operational queues. Carry the integration risk.
The Constantinople purchase
Configure one operating layer, select managed services, keep the licence and brand, then pay a fee that scales with the bank.
Its partnership with 10x Banking makes this positioning especially clear. 10x provides cloud-native core technology and can look like an adjacent alternative; together, the companies take a combined proposition to market across Asia-Pacific. Paymentology, added in 2025, provides card issuing and processing across Visa and Mastercard as well as digital-wallet tokenisation. Constantinople is broad, but it is not pretending every component must be invented in Sydney. Its job is to make the components behave like one bank.
The risks mirror the ambition. A client that consolidates vendors also concentrates dependence. Every new country brings different payment rails, licences and reporting rules. Managed operations are harder to scale than pure software, and bank migrations are famous for punishing optimistic schedules. The company must prove that configurability does not decay into custom work, that artificial intelligence reduces cost without weakening control, and that one platform can remain reliable as clients grow.
05 / Founder-market fitThey learned the problem inside a big bank
Duncan and Challenor met at Westpac while building a digital banking-as-a-service platform. Duncan had worked across banking, technology and private equity, including time in Silicon Valley, before becoming Westpac’s chief development officer. Challenor brought more than two decades in banking at Citi, JPMorgan Chase and Westpac, where she led Global Transaction Services and Payments and helped launch the bank’s digital bank. Their thesis grew from the expensive, organizational reality of making modern banking work, not simply from dissatisfaction with a consumer app.
That experience helped attract A$32 million in seed funding from Square Peg, AirTree Ventures and Great Southern Bank. Forbes Australia described it as the country’s largest seed round at the time. Prosus Ventures then led a A$50 million Series A in April 2024, with existing investors participating. The valuation remains private. The capital is a clue to the product: building across payments, lending, data, compliance, security and operations is an expensive way to begin a software company.
The culture borrows knowingly from its name. Constantinople presents the ancient city as a story of strategic reinvention after Rome’s systems had declined. Its workbench is Justinian. Its rallying cry is “To the Bosphorous!” - spelling and exclamation mark included. Under the historical decoration is a blunt set of operating principles: ship quickly, write clearly, design security in, engineer for outcomes and regard operations as part of the product. The team spans more than 25 countries and works across Sydney, Singapore and India.
06 / What to watchThe invisible company with visible consequences
Constantinople will rarely be the name on a customer’s phone. That is the point. Its success will appear as somebody else’s faster account opening, clearer transaction history, cheaper bank launch or less painful call to support. The near-term evidence will come from execution: Great Southern Bank adding products, MYOB deepening Solo Money, Tyro moving into banking and MoveBank completing its migration.
The larger test is whether a company can turn a bank’s fragmented operating model into a repeatable service without sanding away what makes each client distinctive. If Constantinople succeeds, its advantage will not be a single feature competitors can copy. It will be the accumulated reliability of the whole - the integrations, controls, workflows and institutional knowledge that sit between a customer tapping “pay” and money arriving where it should. The most consequential fintech infrastructure tends to be noticed only when it fails. Constantinople is building a business around remaining usefully invisible.
For customers, the practical measure will be pleasantly ordinary: Can a small-business owner open an account in minutes? Can a member see a useful spending insight? Can a banker resolve a hardship case without switching screens? Can an auditor reconstruct the decision later? Constantinople’s sweeping pitch will ultimately be won or lost through thousands of moments like those. The company is not trying to make banking look futuristic. It is trying to make a complicated institution feel coherent - to the people who run it and the people who should never have to think about how it runs.