Financial Services
In financial systems, being eventually right is a different product to being right. The engineering is almost entirely about the gap between the two.
What’s actually hard here
The constraints that decide the architecture.
Not the sector’s challenges in general. The specific things that make software for it hard, and that anyone proposing to build it should already know.
Reconciliation is the system, not a report
Two systems holding the same transaction and disagreeing is the normal state, not the exception — different cut-offs, different rounding, a fee applied on one side. The organization's real reconciliation engine is usually a person with a spreadsheet whose error rate is nobody's metric and who is on leave next week. Building the reconciliation properly means deciding, in writing and with the people who own both sides, which system is right and what a duplicate means. The code is downstream of that decision.
Settlement windows make time part of the data model
A payment confirmed at 16:59 and one confirmed at 17:01 are in different worlds, and a system that stores a timestamp without modelling the window has thrown away the thing that determines the outcome. Late, out-of-order, and duplicate confirmations are not edge cases here — they are Tuesday. Every path has to cope with the same confirmation arriving twice, or the same money moves twice.
The audit trail is a product requirement
'What happened to this transaction, when, and who touched it' has to be answerable without a developer opening a database, at a moment nobody chose in advance. Retrofitting that history onto a system that did not record it is not a feature, it is a rewrite — which is why it is decided on day one, not when the auditor asks.
Being down is a regulated event
Availability here is not a quality attribute, it is an obligation with an external audience. That changes the deployment, the recovery plan, and specifically whether anyone has ever actually restored from the backup — as opposed to having one.
How we engineer for it
The practices this sector actually needs.
No platform here
We don’t have a platform for this, and we’re not going to pretend otherwise.
We have not built a financial services platform, and we are not going to tell you one of our existing four fits. Reconciliation, settlement, and audit are too specific to an institution's actual obligations to be met by something built for a different industry. This is custom engineering work, and it is exactly the class of problem we take on.
Tell us what cannot go wrong.
If the constraints above look like your constraints, that is the conversation we want. You will speak to an engineer.