How to replace your conversion rate optimization agency

When a Shopify store stops working with its conversion rate optimization (CRO) agency, progress often stalls. Audits sit in a shared folder, tests stop running and nobody owns the next change. If you plan to replace your CRO agency, or have just ended one, a clean handover and a simple routine can prevent that stall.

Start by deciding what done means. In many agency engagements, much of the output is documents: an audit, a roadmap and a monthly report. From here on, a finding is done only when the change is live on your store and its impact is measured.

Before you replace your agency, collect its work

You paid for everything the agency produced, so make sure it stays with you. Ask while the people who did the work can still answer questions, and get files you can open without the agency’s help:

• Audits and research notes, such as heatmap, session-recording and survey findings.
• The roadmap, with each item marked shipped, in progress, rejected or not started.
• Test results with the raw numbers behind each one.
• Every theme change the agency made, and any apps or scripts it installed.
• The accounts and access it holds, so you can remove them after the handover.

Keep the rejected ideas and losing tests too. They stop you from spending traffic on questions your store has already answered.

Price every open finding in $/month

Agency recommendations often arrive without a value attached, like “improve the mobile menu.” As “Why most conversion rate optimization audits never ship” explains, unpriced findings tend to lose to work someone is actively asking for. So give every open item an estimated monthly value, and show the arithmetic.

For example, with made-up numbers: 5,000 visitors reach the cart each month, and a clearer shipping message lifts the share who start checkout by one percentage point. That’s 50 more checkout starts. At a 60% checkout completion rate and a $55 average order, the fix is worth about $1,650 a month.

Then rank the backlog by value, weighed against effort and risk. Anything you can’t size yet goes to the bottom until you have the data.

Make shipping safe and reversible

Fixes stall when every theme edit feels risky, because risky work waits for a developer and a sprint. So build each change on a copy of your live theme, preview it in your own store, check it with Shopify’s Theme Check and log what changed so you can undo it quickly.

With those safeguards, a small fix such as a corrected size chart doesn’t need to wait for the next sprint, while bigger projects follow your usual process. Our post “Letting an AI touch your Shopify theme safely” has a four-question checklist for any tool that edits your theme.

Measure each change against a control

Before-and-after comparisons are easy to misread, because promotions, seasonality and traffic mix move your numbers at the same time. Run the current version and the new one side by side instead, with visitors split between them. Choose the metric and the test length before you start, so nobody picks the result after the fact.

Low-traffic pages can take a long time to give a clear answer; say so instead of calling a result early. Keep the winners, roll back the losers and record both.

Run conversion rate optimization in-house, week by week

A short weekly review keeps the work moving. Give it one named owner and the same agenda every week:

• What went live last week, and the estimated monthly value of each change.
• Which tests finished, what they showed and which changes stay or roll back.
• The top of the priced backlog, and what ships next.
• Anything blocked, and who will unblock it.

Keep the notes in one place. That way the history of what shipped and what it did stays with your store, whoever works on it next.

When keeping an agency still makes sense

A CRO agency replacement doesn’t have to be all or nothing. Some work fits poorly into a weekly loop of small theme changes: a full redesign, for example, or in-depth customer research through interviews and usability sessions. Keeping an agency for projects like these, while you run routine fixes and testing yourself, is a reasonable split.

An agency can also be the right call if nobody on your team has time to own the weekly review. In that case, its project management may be the part worth paying for.

How HI Engine runs this loop

HI Engine started inside a Shopify agency and is built on five years of CRO work for Shopify stores. It runs one loop that finds, prices, ships and tests every fix. HI reads Shopify and GA4 (read-only until you ask for a change), explains each conversion leak in plain language and estimates each fix’s monthly impact, weighing effort and brand risk. It sticks to on-site conversion: no traffic, SEO or ads proposals.

It then writes the fix into your theme as native Liquid, JSON and CSS, the same code your developers would write. HI runs Theme Check and holds the change on a draft theme, so you can preview it in your own store. Nothing goes live without your approval, every change is logged and rollback is one click.

Every fix runs as an experiment: visitors are split 50/50 per browser and each change is measured against a control, with no third-party A/B app needed. Winners stay, losers roll back and results go into your store’s knowledge base.

Pricing is custom after the trial, from $700/month, based on your store size, credit usage and results. The 14-day trial itself is free: we ship your first 3 fixes in the first month, and you pay only after they’re live and you’ve seen the results.