Build
Software at the speed of your ideas.
Production-grade software, fixed price, delivered in weeks. We scope it against a signed done-test, then build it with the delivery risk on us: we deliver the signed done-test in full, or you don't pay.
Production-grade means hardened for security and errors, observable, GDPR-ready, and accessible. The signed done-test records which of those layers each delivery includes.
How the fixed price works
Shaping pass
A short paid engagement turns your brief into a detailed spec. You can walk away after shaping with no further obligation.
Signed done-test
An objective, demonstrable definition of done, written together and signed by both sides. It records which hardening layers each delivery includes.
Fixed price
The price commits only once the done-test is signed. Scope changes are a written change request with a revised price and done-test.
Money back
If a check misses at the demo, we fix it at our cost until it passes. Delivered in full or fully refunded; time overruns are ours to absorb, never yours to fund.
The full mechanism is Step 0 of how we work.
How We Engage
Every customer's situation is different. These are the build engagements we offer, each one scoped independently, priced upfront, and delivered against a signed done-test.
Shaping Pass
The paid first step of every build
- Turns your brief into a detailed spec and a signed done-test
- For legacy systems: includes discovery with codebase access, demonstrably deleted afterwards
- Output: spec, signed done-test, and a single fixed price
Rapid Prototype
2–5 days, validate before you commit
- Working prototype to test assumptions and gather early feedback
- Non-production: focused on UX, UI, and concept validation
- De-risks the full build before the big spend
MVP Build
Full-stack delivery in weeks
- Frontend, backend, infrastructure, and deployment
- Built to extend: no rewrite needed when you scale
- CI/CD, automated testing, and documentation from day one
Post-MVP Milestones
Ongoing feature delivery against a live product
- Each milestone is a new fixed-price engagement with clear scope
- Continuous delivery against a prioritised backlog
- Same mechanism: fixed price against a signed done-test, delivered in full or money back
Legacy Refactor & Migration
Old tech to modern stack, incrementally
- Any language, any platform; we assess what you have and plan the path
- Incremental migration, not big-bang rewrites
- Data migration with validation, rollback, and zero downtime
API & Integration Builds
Connect your systems, build partner APIs
- Third-party platform integration and custom API development
- System-to-system connectivity and data synchronisation
- Documented, versioned, and production-ready
AI Agents & Automation
Intelligent workflows that work with your data
- Bespoke AI agents, LLM integration, and RAG pipelines
- Process automation that eliminates manual, repetitive work
- Built with guardrails: reliable, auditable, and safe
Experiments and shaping run on a short metered basis, in quarter-day units; everything else is fixed price.
Technical due diligence and security assessments live under Assess.
What We Work With
Technology-agnostic. We work across languages, frameworks, and platforms.
How It Works
We carry the delivery risk, so we control the delivery process. Every change runs the automated quality gates: tests, security scans, and CI, on every commit. Your review happens at milestone sign-off, against working software. For ventures we believe in, we can share in the upside instead of charging full price.
Shaping
We resolve design decisions, scope, and the done-test upfront in a paid shaping pass, so the build is de-coupled from your team. For greenfield projects, we shape from your brief. For legacy systems, shaping includes discovery with access to your codebase to map the landscape first; all code access is demonstrably deleted afterwards.
Prototype
Where appropriate, we build a working prototype to validate the approach before committing to the full build. You see something real before the big spend.
Build milestones
The build is split into milestones, each with a concrete delivery. You see working software at each stage.
Productionisation
Final hardening: extended testing, security controls, deployment, and documentation. Full source code and IP handed over. You own everything, no lock-in.
Warranty & beyond
Every delivery includes a warranty period: bugs against the signed done-test are fixed at no cost. After that, ongoing support is a production support agreement, a new fixed-price engagement, or a reserved-capacity retainer.
Why Mangrove
- AI-native delivery: a senior lead directing frontier models, with specialists on demand, delivering production software in weeks
- Secure by architecture: 20+ years in cybersecurity; scanning and isolation on every build
- Regulation-ready: GDPR, FCA-grade data, audit trails designed in, not bolted on
- Full ownership: source, docs, and IP are yours. No lock-in
- Fine-grained control: stop, re-scope, or continue at every stage boundary. The done-test is yours; changes are written; nothing moves without your sign-off.
Fixed priceSigned done-testDelivered in full or money back
Have a project in mind?
Send us your spec or idea. We'll come back with a clear scope and a fixed-price proposal. If the scope needs shaping, we'll propose a short paid shaping pass that turns it into a signed done-test and a fixed price. No obligation.