Service
Advise
Senior technology and security leadership on a reserved-capacity retainer. One family across three commitment levels, from monthly advisory access through to an embedded named-CTO outcome.
Sometimes called a fractional CTO; structured as reserved senior capacity.
The Retainer Family
Same terms across the family. Pick the level of commitment that matches the shape of the engagement. Move up or down when the shape changes.
Advisory
£1,500/month
Founders and small teams who want occasional access to senior judgment.
Standard
£4,500/month
Meaningful continuity for mid-stage companies with decisions in flight.
Embedded
£7,500/month
A named CTO outcome across the business. Top of the family.
We hold a small number of retainer slots, so each client gets senior attention, not a junior with an escalation path. At most two clients fit at Standard or Embedded, and existing clients get first refusal on renewal. The cap is what keeps the attention senior.
What every package includes
- Reserved time, scheduled at our discretion against an agenda we set together
- A month's notice to cancel; cancelling releases the reserved slot
- Days are reserved for the month, not rolled forward
- Overflow billed in arrears on the same package basis
- Move between levels when the shape of the engagement changes
What it deliberately does not buy
- No response-time SLA, no on-call, no escalation rights
- No drop-everything availability between scheduled days
- No production-incident cover; running systems live under a separate support agreement
- Urgent date-bound work runs as scope-locked, fixed-price delivery against a signed done-test, not a retainer pull
Reserved capacity sells you time on our calendar, not pager-grade availability. Need something built to a fixed date for a fixed price? Fixed-scope delivery against a signed done-test is the right product. Retainer clients get priority access to the queue.
The retainer steers a build programme
Reserved capacity earns its keep when there is something to steer: an active or committed build programme, a product in flight, decisions with money behind them. Where there isn't one yet, a fixed-scope build or a standalone assessment is the better first engagement, and we will say so.
How a month runs
We agree the agenda at the start of each month and schedule the reserved days against the work. Active engagements get a weekly written update; everyone gets a quarterly scorecard.
Month opens: agenda set together
Review top risks, progress on open items, and upcoming decisions. Agree the priorities for the month.
Days scheduled at our discretion against the agenda
Architecture decisions, board-deck prep, vendor evaluations, security review, strategic planning. Whatever the agenda carries.
Weekly written update, quarterly scorecard
Active engagements get a one-page Friday report. Every quarter, a board-ready scorecard covering the metrics that matter most.
Advisory Topics
Your retainer adapts to whatever matters most. Each topic could be a single session or an ongoing focus across multiple months.
Strategy & Planning
- Technology roadmap and 90-day delivery plans
- AI strategy: what's real, what's hype, where to start
- Architecture review, scalability, and technical debt
- Cloud strategy and migration planning
- Build vs. buy decisions with the trade-offs stated plainly
Security & Compliance
- Cybersecurity posture review and risk assessment
- Cyber Essentials, ISO 27001, and GDPR alignment
- Incident response planning and crisis preparation
- Supplier and vendor security assessment
People & Operations
- Technical hiring strategy, job specs, and interview support
- Engineering team structure and productivity metrics
- Vendor and supplier evaluation: independent, no kickbacks
- Support operations, SLAs, and operational improvement
Board & Governance
- Board-ready technology and cyber risk reporting
- Budget development, cloud cost optimisation, and spend governance
- Data architecture, governance, and quality assessment
- Due diligence preparation ahead of fundraise or sale
The Quarterly Scorecard
Every quarter, retainer clients receive a board-ready scorecard covering the metrics that matter most to their business. We select the areas together. Common examples include:
Who This Is For
Startups & Scale-ups
Companies with a build programme in flight that need senior technology leadership but aren't ready for a full-time CTO hire.
Non-Technical Founders
CEOs and founders who need a trusted technical advisor to help make confident technology decisions.
Boards & Investors
Organisations that need independent technology oversight and board-level reporting on technology and cyber risk.
CTOs Who Value a Sounding Board
The best leaders still use a coach. An experienced second opinion on strategy, architecture, and stakeholder management, someone to pressure-test decisions with, not report to.
Why Mangrove
- 20+ years as CIO and CTO: we've sat in the chair, from startups to enterprise, across financial services, cybersecurity, and beyond
- Security built in: 20+ years in cybersecurity, including CEO of a cyber defence startup. Security leadership comes standard, not as an add-on
- AI-literate: we can assess AI opportunities and vendor claims properly, not just parrot the hype
- Scarcity is structural: capacity is deliberately capped, so a retainer buys the partner's attention, not a slice of a delivery team
Need senior technology leadership?
Book a free 30-minute call. We'll tell you whether a retainer is the right shape, which level fits, or whether a fixed-scope build or assessment should come first.