Expertise
Core Banking Systems
Core banking implementation, modernisation, and migration for regulated financial institutions. From legacy mainframe estates to modern cloud-native platforms — delivered with the operational discipline that core migrations actually require.
The core banking system is the ledger of the bank. Every account, every posting, every balance flows through it, and any change to it is a change to the most heavily audited system in the organisation. We help institutions implement new cores, modernise legacy ones, and migrate between them — with the discipline that comes from understanding that "go-live" in core banking is the start of the engagement, not the end. Our work covers greenfield implementation for new banks and neobanks, multi-year modernisation programmes for established institutions, and the integration work that makes the core part of a functioning bank rather than an isolated platform.
What we build
Greenfield core banking implementation
End-to-end implementation for new banks, neobanks, and challenger institutions launching on a modern cloud-native core. Includes target operating model design, platform configuration, product setup (current accounts, savings, lending, cards), integration architecture, and the regulatory dossier needed for licence applications. We have delivered this on modern platforms where speed-to-licence and unit economics matter as much as functional fit.
Legacy core modernisation
Multi-year modernisation programmes for established banks running on COBOL mainframes, AS/400, or first-generation packaged cores. We design phased modernisation paths — product-by-product, portfolio-by-portfolio, or geography-by-geography — that retire legacy gradually rather than betting the bank on a single cutover. Includes business case development, vendor selection, target architecture, and programme governance.
Core banking migration and cutover
The hardest part of core modernisation is moving live customer data and transactions from one system to another without breaking the bank's operational and regulatory obligations. We design migration with explicit parallel-running, reconciliation gates at every step, and tested rollback procedures. Volume keeps flowing; balances stay correct; regulators stay informed.
Customisation, extensions, and integration
Configuration of the core platform to match your product set, plus the extension work needed where out-of-the-box configuration cannot reach — custom modules, API extensions, event handlers, and the integration layer connecting the core to channels, payments, CRM, risk, AML, and the data warehouse. Built with versioning and upgrade safety so vendor releases do not break what we built on top.
Data migration and reconciliation
The workstream most often underestimated in core programmes. We treat data migration as a programme in its own right: data quality assessment, mapping design, conversion engine build, multiple dress rehearsals, day-1 reconciliation, and the documentation auditors and supervisors expect to see. The goal is not "data migrated" — it is "every customer, every balance, every history, intact and reconcilable on day 1."
Post-go-live stabilisation and optimisation
The first six months after core go-live determine whether the programme delivers value or becomes the source of the next major incident. We support stabilisation with embedded operational presence, performance tuning, incident management, and the regulatory engagement that supervisors expect after a major change. Engagements include the runbook, the on-call coverage, and the explicit exit plan.
Why banks work with us on core systems
Platform specialists
Core banking platforms reward depth, not breadth. Our team works hands-on with the major platforms, with the configuration patterns, integration interfaces, and operational quirks that come from delivery rather than from training material. Where mandates need platforms outside our in-house bench, we mobilise certified specialists through our extended network.
Greenfield and modernisation, not just one
We have done core programmes from both ends — new-bank greenfield builds where speed matters, and multi-decade legacy modernisations where caution matters. The lessons cross over: greenfield programmes benefit from the rigour of modernisation work, and modernisation programmes benefit from the velocity discipline of greenfield. Most consultancies have done only one.
Migration without the big-bang trap
The historical core migration playbook — multi-year programme, single cutover weekend, fingers crossed — has the failure rate that you would expect. We design migration as a sequence of smaller, reversible moves: product-by-product, portfolio-by-portfolio, or co-existence with the legacy core for as long as it takes. Slower on paper, dramatically less risky in practice.
Built around the regulatory perimeter
Core systems sit under direct supervisory scrutiny. We design changes with the regulator engagement model baked in — change notifications, model approval where relevant, parallel-running evidence, and the documentation supervisors will ask for during their post-implementation review. No retrofit programmes.
Integration-first, not core-only
A modern core is one component of a banking platform that also includes channels, payments, CRM, AML, risk, and the data layer. We design the integration architecture alongside the core itself — API contracts, event streams, idempotency rules, settlement reconciliation — so the core lands as part of a coherent platform rather than as a replacement project that creates new integration debt.
Production-grade, not proof-of-concept
We measure success in production stability, regulatory clean-bills-of-health, customer impact metrics held, and an operations team that owns the platform after we leave. Engagements include the handover, the documentation, and the post-go-live presence — not a slide deck declaring victory at cutover.
Related Services
Solution Design
Technical architecture for regulated financial institutions — the bridge between strategy and implementation. Integration architecture, data design, security and compliance built in, and non-functional requirements specified to the level engineering can actually build from. Vendor-neutral across the platform stack; senior architects with hands-on production experience.
IT Strategy
Multi-year technology roadmaps for regulated financial institutions — current-state assessment, target architecture, vendor and sourcing strategy, business case modelling, and regulatory-driven platform decisions. Led by senior partners with hands-on banking implementation experience, vendor-independent across the cloud and platform stack, with MBAs from London Business School and Columbia.
Custom Rust Development
Rust development for the integration layer of banks and fintechs — ISO 8583 and ISO 20022 message processing, payment routing, and the components where memory safety and predictable performance map directly to operational concerns. A focused capability for the parts of the banking stack where Rust earns its place.
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