About

Why one person does both

I'm Geischglin Rojas, and GRC Prisma is a one-person practice in London doing two things that are not usually done by the same person: bookkeeping, and building software.

Credentials

Two degrees, in that unlikely order

My first degree is in Computer Science, from the Universidad Politécnica de Madrid. I have written software for longer than I have kept books.

The second is a first-class degree in Accounting and Financial Management from the University of Northampton, and it is not decorative: I run the finance function for a UK restaurant. That means sole charge of the books, the reconciliations, the VAT work and everything that has to balance at the end of the month — with the consequences of getting it wrong landing on me rather than on a supervisor.

Two disciplines, both practised rather than studied. That is the whole of the claim.

Scope

Where the line is

For now the finance work is bookkeeping rather than accountancy practice. I don't prepare statutory accounts and I don't file tax returns. If you need those, we can talk through the options — and what I hand your accountant will make their part of it cheap.

Saying so plainly costs me enquiries. It is still the right way round: an engagement that starts with a misunderstanding about scope ends badly for both of us, usually in the busiest week of the year.

The combination

It pays off in both directions

Knowing what a card settlement actually is — one credit covering forty transactions, less fees, landing two days later — means I can build a system that takes payments without quietly corrupting the VAT position behind it. Most payment integrations are technically correct and financially wrong, and the gap does not show up until a quarter-end.

It runs the other way too. Having built systems, I can look at a bookkeeping process and tell which parts are load-bearing and which are just how somebody did it once and nobody revisited. A process that exists because of a limitation in software retired in 2019 is a surprisingly common thing to find.

Whichever one you came for, you get both. In practice that shows up as bookkeeping that understands the systems producing the data and software that understands what the data has to do afterwards.

How I work

One person, responsible for the seams

I take projects from data model to interface, deployment and handover myself. One person responsible for whether the whole thing works, rather than one per part and nobody for the joins between them.

What matters is what happens after launch. A website is not much use if the owner has to call the developer to change a price. An internal tool is not finished if nobody can maintain the data. I build around what the client actually needs to do with the system, and hand over something they can run themselves — the portfolio is largely a record of that principle being tested over several years.

Where

London, and two languages

I'm based in London. The bookkeeping clients are UK businesses, in London and remotely across the country. The web clients are in the UK, Spain and Bolivia, and I work in English and Spanish — writing both, so the Spanish side of a build is not a translation of the English one.

Different businesses, different requirements. The constraint is the same everywhere: a system has to work for the people using it, and they have to be able to afford to keep it running.

Start with a conversation

Books, a website, or something that sits across both. The messy version is fine — working out the shape of the problem is part of the job.