Home / Fractional CTO vs Development Agency: Which Do You Need?
Fractional CTO vs Development Agency: Which Do You Need?
A fractional CTO takes ownership of technology priorities, suppliers and delivery. A development agency supplies the team to design, build and test software. Choose the support that fills the gap: senior leadership, development capacity, or both.
For founders and management teams, the practical question is who will turn the business requirement into working software and take responsibility for the result. That could be a customer platform, an integration between business systems or a tool that removes manual work.
Fractional CTO and development agency responsibilities
| Responsibility | Fractional CTO | Development agency |
|---|---|---|
| Business priorities | Agrees outcomes, budget and delivery priorities with your leadership team. | Translates the brief into a proposed solution, estimate and delivery plan. |
| Delivery | Leads the agreed programme, resolves dependencies and holds suppliers to account. | Provides design, development, testing and release capacity. |
| Technical decisions | Owns decisions across your systems, suppliers and longer-term business needs. | Recommends and implements the technical approach within its scope. |
| Acceptance and handover | Checks the result against business requirements and ensures support has an owner. | Demonstrates the work, resolves defects and delivers the agreed documentation and support. |
When to appoint a fractional CTO
Appoint a fractional CTO when the founder is still settling technical disputes, approving changes they cannot assess or chasing several suppliers for one result. The missing capability is an experienced person with authority to make decisions and lead delivery.
We establish what the business needs, decide where to build or buy, set the budget and manage the work through to implementation. That includes the systems, data and operational changes surrounding the software.
When to appoint a development agency
Choose an agency when you need a delivery team and have someone capable of owning the brief, budget and acceptance decisions. Agencies can provide discovery, product strategy and technical advice as well as development. Assess those capabilities alongside their delivery experience.
Before appointing one, agree what is included, how changes are priced, who owns the code and accounts, and who supports the system after launch. A clear handover matters as much as a convincing demonstration.
How a fractional CTO and agency work together
The fractional CTO represents your business across the programme; the agency leads its delivery team. Agree a single set of priorities, named decision-makers and acceptance criteria so the agency can work without conflicting instructions.
Illustrative example: a growing business needs its sales and finance systems connected. The CTO agrees the process, data ownership, budget and rollout with the management team. The agency builds and tests the integration. The CTO coordinates user testing and adoption, resolves cross-supplier issues and confirms that completed orders reach invoicing correctly.
Budgeting for fractional CTO and agency costs
Seneca’s indicative day rate is £1,100 ex VAT. Two days a month is £2,200 per month ex VAT. Typical fractional engagements run at two to four days a month; the workload determines the time required. An intensive build or recovery may need more.
Add the agency’s development and support fees to that leadership budget. Compare proposals against the same scope, including testing, migration, handover and ongoing support, so a low initial quote does not conceal missing work. We agree our scope and fee before starting, with no standard minimum commitment. Any longer-term discount is agreed separately.
Questions about fractional CTOs and development agencies
Should I hire a fractional CTO before choosing a development agency?
Bring in a fractional CTO first if nobody in the business can define the brief, assess proposals or make the key technology decisions. If those responsibilities already have an experienced owner, you can appoint an agency directly.
Can a fractional CTO manage my existing agency?
Yes. We review the scope, commercial arrangements and delivery position, then take ownership of priorities, supplier management and acceptance of the work. You do not need to replace a capable agency to strengthen leadership.
Will a fractional CTO write the code?
Software development is normally carried out by your agency or internal team. The fractional CTO takes responsibility for the agreed delivery, including technical decisions, priorities, dependencies and whether the work meets the business need.
How much does a fractional CTO cost compared with an agency?
Seneca’s indicative rate is £1,100 per day ex VAT. Two days a month costs £2,200 per month ex VAT. An agency prices its development work separately, so compare the combined budget against the scope, responsibilities and support included.
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