What a £50k software build actually looks like.
When a firm asks "what do we get", the honest answer is a sequence of weeks, a short list of people and a handful of artefacts. This is that list, for one representative Build.
The example below is drawn from current pipeline sizing, not a delivered case. It describes the shape of an HMRC investigation document pack Build at a mid-market tax advisory firm - representative of how we size the work at Discovery exit. When the first Build ships and the firm signs off on a public case study, this essay gets a measured-numbers companion piece.
The people
Two Crofter engineers, one senior and one mid, both named on the engagement letter. A part-time designer for the internal UI. From the firm's side: one business sponsor (typically the MD of the subsidiary), one subject-matter lead (a senior paralegal or a partner), and one IT contact who can grant access to the document store. Nobody else needs to be in the room.
The weeks
Weeks 1–2 - Discovery (already happened)
The Build only starts once Discovery has produced a workflow map, a plan, and the arithmetic. By the time a Build is scheduled, the firm already knows what they are getting, and so do we. The numbers that anchor the refund clause are in the engagement letter.
Weeks 3–4 - Scaffolding
Authentication against the firm's identity provider. Read-only access to the document store. The data ingestion pipeline that will end up reading the client history. A small internal web app behind SSO with the first two pages. At the end of week 4 the sponsor can log in and see something skeletal but real.
Weeks 5–6 - The actual work
The reasoning core: document extraction, timeline construction, citation handling, privilege-flagging. The first five real client cases are run through in parallel with the existing paralegal process. Both outputs are compared by the senior paralegal. We tune against disagreements.
Weeks 7–8 - Hardening and handover
Error handling, permissioning, audit logging. A tuning playbook is written. The Managed retainer takes over. The Build has shipped.
The artefacts
- Engagement letter
- Scope, fixed price, six-month payback clause keyed to the Discovery-plan targets, named engineers, IP assignment, DPA reference.
- Architecture note
- One document, about twelve pages, in plain English. The thing the firm's next engineer reads in one sitting.
- DPIA
- Produced inside Discovery, signed at Build start. A live document for the Managed retainer.
- Source code
- In a Git repository the firm owns. Not a black box.
- Tuning playbook
- The operational manual for the firm's Managed contact. What to monitor, what to change, when to call us.
- Case study draft
- Numbers, methodology, named client - only if the firm is willing to go on record. No surprise press.
How we size the fee
The Build fee is anchored in the Discovery arithmetic, not in a price list. For the HMRC investigation document pack shape, sizing typically reads: thirty paralegal-hours plus three partner-hours per complex enquiry today, a target of eight and one respectively after the Build, and an event volume of around a hundred enquiries a year. At mid-market tax-advisory loaded rates, the arithmetic supports a Build in the forty-five to sixty-five thousand pound range with payback inside six months. Those are sizing numbers set at Discovery exit, not delivered results from a live engagement; the engagement letter binds us to whatever the specific numbers agreed with the firm turn out to be.
If those numbers do not land against the engagement-letter targets inside the refund window, the Build fee is refundable. We write that into the engagement letter because we think the question "was this Build worth doing" should be the firm's to answer, not ours - and the mechanism for answering it should be mutually signed, not asserted from our side.