Industry
Software engineering for Finance
Software for financial services, where a rounding error is not a bug you get to laugh about later.
Why the domain matters
Financial services is a broad sector, and this page is deliberately the broad one. We use “finance” here to mean the wider world of firms that manage, move, report on and account for money at professional scale: investment, asset and wealth managers; capital-markets and trading desks; the finance functions inside larger businesses; and financial-services firms generally that need software touching portfolios, transactions, market data and the ledger. It sits alongside our more specific pages: fintech for consumer-facing financial products, banking for institutions holding deposits and running core banking, lending for credit and loan origination, and payment platforms for money movement, and where your need is genuinely one of those, that narrower page is the better read. If your work is investment management, financial reporting, reconciliation, risk and compliance reporting, or the accounting systems that underpin all of it, you are in the right place.
The defining constraint of this sector is not speed, and it is not scale, though both matter. It is correctness. Software that touches money has to be right in a way most software does not. A rounding error in a social app is a cosmetic annoyance; the same error across a portfolio of ten thousand positions is a misstated valuation, a wrong fee, a failed reconciliation, and potentially a regulatory problem. Every number a finance system produces has to be reproducible, explicable and traceable back to its inputs, because sooner or later an auditor, a regulator, a client or your own finance team will ask exactly how it was arrived at, and “the software calculated it” is not an answer. We build for that world: systems where correctness and auditability come first and cleverness comes a distant second.
The other hard truth about this sector is that the interesting work is rarely a greenfield application on its own. Finance runs on entrenched systems (accounting platforms, order and execution systems, custodian records, market-data feeds, fund administration), most of which predate whatever you are building and none of which you get to replace. The genuinely difficult engineering is integrating cleanly and correctly with those systems and data sources, reconciling what they tell you, and producing a single trustworthy number when several sources disagree. We are candid that this integration and reconciliation work is where the effort goes, and where projects that underestimated it come unstuck. It is also where we do our best work.
The challenges in finance
Correctness that has to be provable
It is not enough for the numbers to be right; you have to be able to demonstrate they are right, on demand, months later. Valuations, fees, returns and reconciliations all need to be reproducible from their inputs, which shapes how the whole system is built, deterministic calculations, retained inputs, and no quiet mutation of figures after the fact.
Reconciliation across disagreeing sources
Your custodian, your accounting system, your trading platform and your own records will not always agree on positions, cash or transactions. A finance system that cannot reconcile these and surface the breaks (clearly, with a trail), is worse than useless, because it manufactures false confidence in numbers that are quietly wrong.
Money arithmetic done properly
Floating-point maths, naive rounding and inconsistent currency handling cause real financial errors that compound across large books. Getting decimal precision, rounding conventions, currency conversion and fee calculation exactly right is unglamorous, easy to get subtly wrong, and non-negotiable in this sector.
Integration with entrenched, unlovely systems
The systems of record (fund administration, accounting, custodian and order-management platforms), are often old, poorly documented and not designed to be integrated with. Getting reliable data in and out of them, in the right shape and at the right time, is consistently the hardest and most underestimated part of any finance build.
Market and reference data that is messy and expensive
Prices, corporate actions, instrument identifiers and reference data arrive from feeds with their own quirks, gaps, latencies and licensing rules. Ingesting them reliably, handling missing or late data without silently producing wrong valuations, and respecting the vendor’s terms is a discipline in itself.
Regulatory reporting that must tie out
Reports to the FCA, to clients and to auditors have to be consistent with each other and with the underlying records. When the compliance report, the client statement and the ledger tell three different stories, you have a problem long before anyone external notices, and building so that they agree by construction is far cheaper than reconciling them by hand every period.
What we build for finance
The systems this sector most often needs, built by engineers who understand the domain, not just the code.
Portfolio and investment management systems
Bespoke systems for managing portfolios, positions and mandates (holdings, transactions, valuations, performance and fee calculation), built around correct money arithmetic and a clear, auditable link from every figure back to the trades and prices that produced it. Tailored to how your firm actually invests rather than bent to fit a rigid off-the-shelf product.
Financial reporting and reconciliation tools
Software that reconciles positions and cash across your records, custodians and accounting systems, surfaces breaks clearly, and produces reporting that ties back to source. The aim is to replace fragile spreadsheets and manual month-end scrambles with a repeatable, checkable process that finance teams can actually trust.
Trading and market-data dashboards
Interfaces that bring together market data, positions and orders into a coherent, real-time view for the people making decisions, pulling from your data feeds and trading systems rather than replacing them, and honest about the difference between a decision-support dashboard and a low-latency execution system.
Finance-team automation
Automating the manual work that accretes around any finance function (reconciliations, rekeying between systems, report assembly, fee runs, close processes), through proper integrations and validated calculations rather than yet another spreadsheet macro nobody dares touch. The point is to remove the error-prone copy-paste, not to hide it behind a nicer button.
Risk and compliance reporting systems
Systems that gather the data behind risk and regulatory reporting, apply the required rules and calculations, and produce outputs that are consistent with each other and with the underlying ledger. Built so that the compliance report, the client statement and the accounts agree by construction, not by heroic monthly effort.
Accounting and back-office integration
Clean, governed integrations between your bespoke systems and the accounting, ERP and fund-administration platforms that hold the authoritative record, so data flows reliably in both directions and your operational tools work from the same truth as the books, not a stale, hand-maintained copy.
Where we help
A wealth manager’s client and portfolio platform
A wealth or investment manager needs a single system for client portfolios, valuations, performance and fee calculation, drawing positions from custodians and prices from market-data feeds, with statements and reporting that reconcile back to source. The value is in the correctness and the reconciliation, not the front end alone.
Month-end reconciliation and close automation
A finance function drowning in spreadsheet reconciliations between its own records, the bank, the custodian and the accounting system wants that made repeatable and checkable, breaks surfaced automatically, matched items cleared, and a close process that takes days instead of weeks and produces the same answer every time.
A trading desk’s market-data and position dashboard
A desk needs live market data, current positions and outstanding orders in one place to make decisions, integrated with its existing order-management and data-feed infrastructure. The build is decision support done reliably, not an attempt to become the execution system, which we would say plainly.
Automated regulatory and client reporting
An investment firm needs periodic reporting to the FCA, to clients and to auditors generated from the same underlying records, so the figures are consistent everywhere. We build the pipeline that assembles, calculates and validates those reports against the ledger, replacing a manual process where consistency depended on someone remembering to update three documents.
How we build for finance
We start by being precise about correctness. Before much is built we pin down the money arithmetic explicitly (decimal precision, rounding conventions, currency handling, fee and valuation logic), and we agree how each material figure will be made reproducible and auditable, because these decisions are structural and painful to retrofit. We map the systems and data feeds we will integrate with early, including their quirks and failure modes, because in this sector the integration surface is the project’s real shape and pretending otherwise is how timelines slip. And we say plainly, up front, where the honest boundary is: this software must be right, not merely fast, and where a requirement trades correctness or auditability for speed we will push back rather than quietly accept it.
From there we build in thin, working slices against real data and real integrations rather than tidy mock-ups, so the hard parts (reconciliation, messy feeds, disagreeing sources), surface while they are cheap to fix. The engineers who design these systems are the ones who operate them, which changes how we build: we favour approaches that stay correct and supportable under real-world data over clever ones that demo well and break at quarter-end. Testing in finance is not an afterthought either, reconciliation logic, calculations and edge cases around corporate actions, currency and rounding get tested hard, because a passing demo tells you very little about whether the numbers will still tie out across ten thousand positions on a bad data day.
Regulation and compliance
Most of the firms we build for in this sector are regulated by the Financial Conduct Authority (investment managers, wealth managers, advisers and other authorised firms), and that shapes what the software must do even though the software itself is not what gets authorised. FCA rules on client money and assets (CASS), on suitability and record-keeping, and on the treatment of clients run straight through any system handling portfolios, transactions or advice. Where a firm’s activities fall under MiFID II, requirements such as transaction reporting, best-execution record-keeping and detailed client reporting land directly on the systems that hold and produce that data. We are not your compliance function and we do not give regulatory advice, but we build software that makes your obligations straightforward to meet, with the records, controls and reporting the rules assume you have.
Financial reporting standards matter too. Figures that feed statutory accounts, fund reporting or client statements have to be calculated and presented consistently with the relevant standards, and (just as importantly), reproducibly. Auditability is the throughline of everything here: an auditor or regulator is entitled to ask how any number was produced, and a system that cannot answer has failed regardless of whether the number happened to be correct. And because all of this involves personal and financial data, UK GDPR and the Data Protection Act apply in full. We design so that the audit trail, the retained inputs and the data-protection controls are part of the architecture from the start, not bolted on when someone asks for them.
Integration
Integration is the centre of gravity for finance software, not an afterthought, and we plan projects around that reality. The systems you will need to connect to typically include one or more market-data feeds for prices, corporate actions and reference data; order-management or execution systems on the trading side; custodian records for positions and cash; and the accounting, ERP or fund-administration platform that holds the authoritative ledger. Many of these are old, idiosyncratic and were never designed to be integrated with: batch files at fixed times, proprietary formats, partial or delayed data, and financial APIs that vary enormously in quality. Mapping these interfaces, their data contracts, their timings and their failure modes before writing much code is the single highest-leverage thing we do, because integration defects in finance are expensive to find in production and cheap to prevent at the design stage.
The reconciliation problem lives on top of the integration problem. Once data is flowing from several sources, they will disagree, and the system has to detect, surface and help resolve those breaks rather than silently pick a winner. We build integrations that are observable and idempotent: that can be re-run safely, that log what they received and produced, and that handle missing or late data by flagging it rather than quietly computing a wrong valuation. Where the accounting or ERP system is the system of record, we treat it as such and keep our data in step with it through governed, two-way flows, rather than letting a hand-maintained copy drift out of agreement with the books.
Security
Financial data is among the most sensitive a firm holds (client holdings, transactions, valuations, personal details and the firm’s own positions), so the security bar is high and non-negotiable. We enforce authorisation on the server for every action and every piece of data, never merely hiding options in the interface; we scope access tightly, so a user, a service or an integration sees only what its role genuinely requires; and we hold secrets and credentials for data feeds and downstream systems in a proper vault rather than in code or configuration. Data is encrypted in transit and at rest as a baseline, and we are deliberate about data minimisation: an API or report that over-exposes financial data is a breach waiting to happen, so each interface returns the specific fields a use case needs and no more.
Audit is inseparable from security in this sector. Because the same reproducibility that satisfies an auditor also underpins accountability, we log who accessed and changed what, and retain the inputs behind every material calculation, so activity can be reconstructed after the fact. Access control is designed around real segregation of duties where the regulatory and operational context calls for it, and privileged access to anything touching client money or positions is treated with the seriousness it deserves. The consistent principle is that in software handling money, the controls are not a layer you add at the end. They are part of how the system is built.
What changes
Numbers you can defend
Every material figure the system produces is reproducible and traceable back to its inputs, so when an auditor, regulator or client asks how it was arrived at, you have an answer, not a shrug and a re-run that gives a different result.
Reconciliation you can trust
Positions and cash reconcile across your records, custodians and accounting systems automatically, with breaks surfaced clearly, replacing the manual, spreadsheet-bound scramble that hides errors rather than catching them.
Manual finance work removed, not repackaged
The error-prone rekeying, report assembly and month-end shuffling are automated through proper integrations and validated calculations, so your team spends its time on judgement rather than on copy-paste that a system should have done.
What we build for finance
From a first platform to modernising what you already run. The disciplines this sector draws on most.
How we deliver
- 01
Discover
We map the system, the constraints and the business it serves, including the parts nobody documented.
Architecture brief
- 02
Architect
Decisions get made, written down and defended before a line of production code exists.
Decision records
- 03
Build
Short cycles against working software. You see progress in the product, not in a status deck.
Shipping increments
- 04
Operate
Monitoring, incident response and iteration. The system is alive, so the engagement is too.
Runbooks & SLOs
Building something for finance?
Tell us the problem and the constraints you are working under. A senior engineer will give you a straight view on what it would take, and say so plainly if we are not the right team for it.
Technologies we work in
Chosen per problem, not per fashion. A selection of the stack we most often reach for.
Why teams in finance choose us
We treat correctness as the requirement
In finance the numbers have to be right and provably so. We build deterministic, auditable, well-tested calculations and reconciliations because we understand what a rounding or reconciliation error actually costs, not as a nice-to-have, but as the point of the exercise.
We are honest about the integration
The hard part is connecting to entrenched accounting systems, custodians and data feeds and reconciling what they tell you. We say that up front, scope for it properly, and do not pretend a finance project is a greenfield app with a bit of plumbing on the side.
We operate what we build
The senior engineers who design your system run it, so we build for quarter-end and the bad-data day eighteen months out, not for the demo. That means integrations that stay reconciled and calculations that stay correct under real conditions.
Senior engineers only, and clear on our lane
Software touching money is not a place to learn on the job. The people building yours have done it before, and where your need is really consumer fintech, core banking, lending or payments, we will point you to the right specialist rather than overreach.
Common questions
How is this different from your fintech or banking pages?
This is the broad financial-services page, investment, wealth and asset management, capital markets, finance functions and financial-services firms generally. Fintech covers consumer-facing financial products, banking covers deposit-holding institutions and core banking, lending covers credit and origination, and payment platforms cover money movement. If your need is clearly one of those, that narrower page is the better fit. If it is portfolio management, financial reporting, reconciliation, risk and compliance reporting, or accounting integration, you are in the right place.
Do you guarantee the numbers will be correct?
We build for correctness as the first requirement, deterministic calculations, defined rounding and precision, reconciliation against source, and hard testing of the money arithmetic and edge cases. No responsible engineer guarantees the absence of all bugs, but we design so that figures are reproducible and auditable, so that discrepancies surface rather than hide, and so that when something is questioned you can trace exactly how it was produced. That combination is what makes finance software trustworthy, and it is what we deliver.
Can you integrate with our accounting system, custodian and market-data feeds?
Yes. This is the core of most of what we do here. We integrate with accounting and ERP platforms, custodian records, order-management systems and market-data feeds through their supported interfaces, and we build the reconciliation that sits on top when those sources disagree. We map each integration’s data contracts, timings and failure modes before building, because in finance that integration surface is where the real effort and the real risk live.
Are you a compliance or regulatory adviser?
No. We are engineers, not your compliance function, and we do not give regulatory or financial advice. What we do is build software that makes meeting your obligations straightforward: the records, controls, audit trails and reporting that FCA rules, MiFID II where it applies, financial reporting standards and data-protection law assume you have. We work alongside your compliance people rather than replacing them, and we build so the reporting they rely on ties back to source.
Can you build us a low-latency trading system?
We will be straight with you about the distinction. We build reliable decision-support tools: dashboards bringing together market data, positions and orders, integrated with your trading and data infrastructure, and finance systems where correctness and auditability matter most. Ultra-low-latency execution engines are a specialist discipline with their own extreme constraints, and if that is genuinely what you need we will say so rather than take work we are not the right shop for. Most firms asking for “trading software” need the former, done correctly, and that is squarely what we do.
Building for finance?
Tell us what the system has to do and what it cannot get wrong. A senior engineer reads it, and if finance is not a domain we know well enough to be useful in, we will say so rather than learn it on your budget.
- 01A senior engineer reads it. Not a form queue, and not an account manager.
- 02We reply either with questions or with a straight answer that we are not the right fit.
- 03If it looks like a fit, a technical call with the person who would actually run the delivery.
- 04Then scope, effort and risk in writing, before anyone signs anything.