By Chris Ledden · Reviewed October 2026
This summer I dug into Daily Bloom’s email program, which an agency had been running for us. On paper it looked great: open rates of 80% and up. Clicks were under 1%. When I pulled the segments apart, the “engaged” audience was counting Apple Mail’s automatic opens as real people. The automation that was supposed to clean our list had exactly one person in it, because it depended on a profile field nobody was filling in.
To their credit, the agency rebuilt those segments within three days of me showing them. They weren’t acting in bad faith. The problem was simpler: nobody on our side of the table could read the account well enough to ask.
That’s the whole difference between these two roles. An agency builds things. A fractional CTO decides what should be built, in what order, and checks that it was built well.
Side by side
An agency gets paid for work delivered, so it naturally leans toward building more. That’s not cynical, it’s the business model. My job is to get you the result with the least work, and sometimes that means building nothing at all.
You need an agency if
You need a new theme, a redesign, or a migration
You have a steady list of design and development work
You already know exactly what you want built and just need it done well
You need a fractional CTO if
You can’t tell whether a quote is fair
Two agencies gave you two opposite recommendations
Your app bill keeps climbing and nobody can say why
You’re weighing Shopify Plus, headless, a new ERP, or a new POD provider
Nobody owns the stack, so every tool got added by whoever needed it that week
You need both if a big project is coming
When we moved Daily Bloom to a new theme this year, I split the work exactly this way. I hired the developer on Upwork and did the CTO half myself: the brief, the app audit, the coding standards, and the QA checklist. The developer built. I decided and checked. We came out with a store that loads in a third of the time and an app bill that’s $683 a month lighter.
How I work with your agency
I don’t replace your agency. I write the briefs, review the quotes and the finished work, and translate between you and the developers. Good agencies usually welcome it, because a clear brief means fewer change orders and fewer surprises for everyone.
Questions
Sources: agency rates and retainers from Tenten’s Shopify agency pricing (2026); fractional CTO ranges from A.Team’s fractional CTO rates guide (June 2026).