Fintech Legacy System Modernization
We move fintech workloads off COBOL, RPG, PL/SQL and Oracle Forms one path at a time, while the ledger of record keeps posting. Each new path runs beside the code it replaces until the two agree record by record, and every cutover is rehearsed with production traffic before it is real. The hard part is not the new service. It is proving that both paths close the day on the same number.
Trusted by engineering teams.
Teamvoy has delivered engineering work for Nasdaq, Panasonic, Afriland First Bank, and 50+ other companies since 2013.
Verified B2B client reviews from fintech, insurance, healthcare, and hi-tech engagements.
A B2B review platform that connects businesses with verified software solutions providers.
Transparent platform where current and former employees share company reviews and interview experiences.
Fintech Legacy System Modernization Services We Offer
Six engagements, each scoped, estimated and stopped on its own. Most clients buy the first one and decide after reading it.
Legacy Assessment and Sequencing
An inventory of the programs, jobs, copybooks and schedules still in service, with a dependency map keyed on what posts to the general ledger. We read the JCL and the batch schedule rather than the architecture diagram, because the schedule is the only artefact guaranteed to be current.
– Program and job inventory
– Copybook and data dictionary extraction
– Batch dependency mapping
– General ledger touchpoint analysis
– Sequencing and risk register
Strangler Facade and Anti-Corruption Layer
A routing layer in front of the legacy core so one transaction type can move while the rest stay where they are. Translation is generated from the copybook definitions, so packed decimal and EBCDIC conversion are asserted in tests instead of discovered at month end.
– Gateway routing and canary rules
– Copybook to JSON contract mapping
– Packed decimal and EBCDIC handling
– Idempotency keys on retried writes
– Routing by account, not by session
Core and Payment Rails Integration
Adapters between the new services and the systems that are staying: the core, the card processor, the screening vendor and the payment rails. The core stays the record of truth and every new store is treated as derived until parity is proven, which keeps the blast radius of a mistake on our side of the boundary.
– Temenos and Finacle adapters
– Mambu and Thought Machine Vault
– IBM MQ to Kafka bridging
– SWIFT, SEPA and Faster Payments
– KYC and screening vendor calls
Data Migration and Parallel Run
Change data capture out of DB2, Oracle and VSAM into the new store, with both paths running on the same traffic. Comparison is per record and includes the fields the downstream report keys on, because two offsetting errors net to zero on totals.
– Change data capture from DB2 and Oracle
– Batch window and end-of-day replay
– Record-level comparison harness
– Break triage and root cause
– Backfill and replay tooling
Cutover and Rollback Engineering
Moving traffic onto the new path and keeping the way back real. The rollback is exercised with production traffic on a schedule, because a legacy path left idle for weeks collects expired certificates, rotated service accounts and licence checks nobody renewed.
– Traffic shifting and canary plans
– Rollback rehearsal with live traffic
– Dual write and reconciliation windows
– Freeze, cutover and thaw runbooks
– Post-cutover monitoring and alerting
Decommissioning and Run Cost Reduction
Retiring the programs, jobs and licences that nothing calls any more. Nothing is deleted until call tracing shows no traffic across a full reporting cycle, quarter end included, and the evidence goes into the change record.
– Call tracing and dead code detection
– Batch job retirement
– Mainframe capacity and licence reduction
– Archive and retention for audit
– Change control evidence pack
Fintech Legacy System Modernization Success Stories
Check out our product and experience design case studies. Learn how we’ve helped businesses like yours launch stunning solutions and succeed in target markets.
Data Migration in Insurance: Moving Data Safely
Hybrid Cloud Banking Architecture: Zero Downtime, ~400K Users, Seven Banks
High-Performance Web Platform for Scalable Trade Surveillance
One posted transaction, seven layers
It looks like one payment moving through a new service. It is seven handovers between the code being replaced and the code replacing it.
You get an engineer’s read on what can move first, not a proposal deck.
-
Channel request and edge routing
The request arrives at the gateway and a routing rule decides whether it goes to the legacy core or the new path. Breaks when the routing key is read from a field that only some requests carry, so a share of traffic quietly falls back to legacy and is never tested. Or the rule is sticky by session rather than by account, and one account is served by both paths on the same day. -
Contract facade and anti-corruption layer
The modern request is translated into the fixed-width message the core expects, and the response is translated back. Breaks when a packed decimal field with implied decimal places meets a floating point value. Rounding differs in the third decimal, the daily totals still reconcile, and the gap only becomes visible on interest accrual after month end. -
Identity and entitlement exchange
The caller is authenticated and mapped onto whatever the legacy system understands as a user and a permission. Breaks when the legacy model is branch and teller shaped and has no concept of a service account. A superset is granted to make the path work, and the first audit finds a role that can post a journal it should never touch.
-
Transaction boundary and idempotency
The new service opens a call that ends in a commit inside the core, then reports the outcome back upstream. Breaks when a timeout on the new side retries a request the core has already committed. With no idempotency key stored on the core side, the debit posts twice. Demos do not retry, so this one shows up first in production.
-
Change capture and parallel run
Committed changes are captured from the legacy store and applied to the new one, and both paths run on the same traffic. Breaks when the end-of-day batch rewrites balances with compensating postings that never appear as row-level changes. The new store is right at 16:00 and wrong at 02:00, and the comparison job runs in the morning. -
Reconciliation and comparison harness
Every record produced by both paths is compared, and differences are triaged before they reach a customer or a report. Breaks when fields judged cosmetic are excluded from the comparison and one of them is the reference the downstream reporting engine keys on. Or the harness compares totals, so two errors in opposite directions net to zero and pass. -
Cutover, ledger write-back and rollback
Traffic moves to the new path, the ledger of record is written by the new code, and the old path is held in reserve.Breaks when the rollback assumes the legacy path is still warm. It has taken no traffic for weeks, so a pinned certificate has expired, a service account password has rotated and a licence check now fails. A rollback that has not been rehearsed with traffic is a paragraph, not a plan.
Do you know which of your batch jobs
still post to the ledger?
-
The engineers who scope the work build the work
No handover from a pre-sales team to a delivery team. The person who tells you what the work will cost is the person who then has to make that estimate true. Costs us: we cannot start faster than we can staff, so we turn down work that needs a squad this month.
-
You own the source code from the first commit
The repository is yours, in your organisation, from day one. Not transferred at the end, not held until the final invoice clears. Costs us: we give up the lock-in that comes from holding a repository, so we have to be re-chosen every quarter.
-
Every cutover is rehearsed with production traffic before it is real
The legacy path keeps taking traffic through the parallel run, and the rollback is exercised on a schedule rather than written down and filed. Parity is checked record by record, not on end-of-phase totals. Costs us: the parallel-run weeks ship no new features, and we put them in the estimate as their own line instead of folding them into the build.
-
We read the code that still runs before we draw the target
The first deliverable is an inventory of programs, jobs and copybooks with a map of what posts to the general ledger, not a reference architecture. That inventory is the only version of your system that is guaranteed to be current. Costs us: our first artefact is a document rather than a demo, which loses us the buyers who want something on screen in week two.
Three ways to start.
Each one ends in something you keep. None of them obliges you to buy the next.
Modernization Assessment
We read the code that is still running: programs, jobs, copybooks and the batch schedule. You get an inventory, a dependency map showing what posts to the general ledger, and a sequencing plan that says which path moves first and why. Yours whether or not we build anything.
One Path Through the Facade
One transaction type routed through a facade in your environment, running beside the legacy path on the same traffic, with a record-level comparison harness and a rollback rehearsed before it is needed. Runs in your accounts, on your repository.
Technical Call
Fifteen minutes with an engineer who has moved transactions off a mainframe core. Bring the batch schedule and the list of systems that read from it. No deck, no discovery workshop, no follow-up sequence.
Two modernization quotes can use the same words and price completely different risk.
Most vendors hand you a deck. Teamvoy hands you a working API and a senior AI engineer who stays until the outcome lands. We charge for results, not for hours.
The difference shows up at the production line. An agent failing on real data. A regulator asking how the model decides. A board asking what AI actually changed.
What our fintech modernization engineers work in.
Legacy runtimes we read
Services we write
Data movement and stores
Cores, rails and vendors
Platform and delivery
Assurance and controls
We engineer for:
Tell us what still runs on the old system.
Talk to a Chief Technology Officer on the first call.
