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Custom software development · London

Custom Software Development for London Businesses

A UK-based custom software development company serving London’s enterprise, fintech, and regulated firms — building audit-ready, AI-enabled SaaS to a verifiable standard, engineered to be inherited.

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Built for London’s market — the honest version

London runs on software that will be audited — by enterprise customers, by regulators, by the next CTO who inherits it. Most engagements fail quietly eighteen months in, when the original team is gone and nothing is documented. We build to make that impossible: a decision trail, threat model, and runbook produced as we go, to OWASP ASVS Level 2 and aligned with the EU AI Act. We’re UK-based and work with London firms directly — we don’t claim an office we don’t have or client logos we can’t name.

For London's regulated and enterprise buyers

Fintech, professional services, healthtech, and government suppliers whose customers run security questionnaires — audit-ready by design.

UK-based, no offshore black box

Real people on UK hours in your timezone — not a handoff to a night-shift team you never meet.

On-site when it helps, remote when it doesn't

We meet in person across London where it moves the work forward, and work remotely where that's simply faster.

You own the IP

Code, configuration, and documentation are assigned to you on payment — no lock-in, wherever your team sits.

How we deliver

Four stages. You are never locked in.

Stage 0 — Discovery & Technical Audit

Fixed fee · 2–3 weeks · credited against the build. You get a system architecture proposal, a threat model, a compliance gap analysis, a phase-level roadmap, and a fixed-price Stage 1 proposal.

Stages 1–4 — Phased Build

2–4 week phases · invoiced per phase. The build is decomposed into phases with written acceptance criteria agreed before each begins. You approve each phase before the next starts, with continuous access to staging, the repository, and a weekly written status report of work, risks, and decisions.

Post-Launch Warranty — 90 Days

Any defect against the agreed acceptance criteria found within 90 days of launch is fixed at no cost. Critical issues in 4 business hours; major issues in 2 business days.

Continuity — Optional

Monthly · scoped to your risk profile. Dependency and vulnerability patching, threat-intelligence response, monitoring and incident triage, and defined enhancement hours.

£50,000–£150,000

Typical production SaaS engagements, depending on scope, integrations, and compliance depth. You approve each phase before you pay, and 100% of the IP is assigned to you on payment.

London questions, answered

We are a UK-based firm and we work with London businesses, meeting in person across the city where it helps and remotely where that's faster. We don't claim a shopfront we don't have — what you get is UK-hours delivery in your timezone, not an offshore handoff.
You work with real people on UK hours — same timezone, no night-shift handoff, and no black box. For London firms selling to enterprises, government, or regulated buyers, that also means a decision trail and evidence a security review will accept.
Typical production SaaS engagements run £50,000–£150,000, depending on scope, integrations, and compliance depth. You're invoiced per phase and approve each phase before you pay, with Stage 0 a fixed fee credited against the build.
Yes. We can build alongside your team or take over an undocumented system cleanly — producing the decision trail, threat model, and runbook so your people own it, not fear it.

Building something London’s auditors will accept?

Book a scoping call. Stage 0 turns your problem into a fixed-price roadmap — credited in full against the build.

Book a scoping callCustom software development
Book a scoping call