Core flow architecture
Welcome, browse abandonment, abandoned cart and checkout, post-purchase, replenishment, winback and back-in-stock — built as one coherent system with exclusion logic so a customer never receives three flows in the same hour.
Klaviyo flows, SMS and integrations
Klaviyo Expert for Shopify
A Klaviyo expert who is also a developer. I build the flows, the segments and the templates — and when Klaviyo does not do what you need out of the box, I write the API integration that makes it happen.
Working with US and Canadian brands · UTC-3, overlapping almost the entire North American business day · fluent English · invoiced in USD
Currently on my desk
- B2C + B2Bstorefronts
- Shopify operation I run today, end to end
- +455%sessions
- international luxury fashion brand
- +254%sales
- US beauty & lifestyle brand
US building-products manufacturer
Day-to-day operator, B2C + B2B storefronts
- storefronts (B2C + B2B)
- 2
- sales channels
- 7+
- Salsify syndication
- PIM
International luxury fashion brand
Sole engineer
- sessions
- +455%
- orders
- +114%
- revenue
- +74%
US-based beauty & lifestyle brand
Took over the operation
- total sales
- +254%
- orders
- +324%
- sessions
- +1,700%
Martin — my own brand
Founder and operator
- orders
- 1,959
- processed
- ~R$552K
- sessions
- 299K
Four stores, four verticals, the same owned-channel playbook behind the growth.
Most Klaviyo work is sold by agencies who can design a beautiful email but cannot touch the data underneath it. That is where owned-channel revenue quietly stalls: events are not firing, identifiers are not stitched, a flow filter excludes half your audience, and nobody in the room can read the payload to find out. I come at Shopify email marketing from the engineering side first, which is why the flows I build stay accurate as the store changes.
I built and ran the Klaviyo stack for an international luxury fashion brand as its sole engineer, alongside Meta CAPI, Google Merchant Center and Amazon integrations. Over that engagement the store went from a broken measurement setup to +455% sessions, +114% orders and +74% revenue. I also ran email and SMS for my own Shopify brand, Martin (martin4shop.com.br), through 1,959 orders and roughly R$552,000 in revenue — so I have written the abandoned-cart sequence that had to actually pay for my inventory, not just look good in a case study.
Klaviyo should be somewhere between a fifth and a third of a healthy store's revenue. If yours is well below that, the problem is almost never the copy. It is segmentation, timing, deliverability or data — and all four are fixable.
Klaviyo and owned-channel services
Segmentation and list health
RFM-style segments, engagement tiers, sunset flows for dead addresses, and predictive-analytics-driven audiences. Cleaning the list is usually the fastest way to lift open rates and protect your sending reputation.
SMS marketing for Shopify
Compliant SMS collection, two-touch welcome, cart and shipping notifications, and campaign cadence that does not burn the channel. Includes consent handling, quiet hours and full US carrier compliance requirements.
Deliverability rescue
DMARC, SPF and DKIM configuration, dedicated sending domain setup, warm-up plans, and diagnosis when your emails start landing in Promotions or Spam. Measurable within two weeks, usually sooner.
Custom events and API work
Klaviyo Track and Identify APIs, server-side events from your backend, custom Shopify metafield sync, subscription and loyalty app data, and profile properties that make real personalisation possible.
Templates and Shopify data
Responsive, on-brand email templates with dynamic product blocks pulled from live Shopify catalog data, so recommendations, prices and stock status are correct at the moment the email opens rather than when it was designed.
Klaviyo developer, or Klaviyo agency?
Owned-channel work splits into two very different jobs, and most stores buy the wrong one. An agency sells campaigns and creative. A Klaviyo developer fixes the data underneath, which is what determines whether any of the creative can work. Below is the honest division, including the parts I do not do.
- What a Klaviyo developer fixes
- Events that never fire, identifiers that do not stitch a browsing session to a purchasing customer, custom properties that arrive as strings when the segment expects numbers, webhooks with no retry, and Shopify metafield data that never reaches the profile at all. None of this is visible in the Klaviyo UI, and none of it gets fixed by better subject lines. This is the half I am hired for most.
- What a Klaviyo agency is better at
- High-volume campaign calendars, brand creative and photography, and copy production at a pace one person cannot sustain. If that is your gap, hire an agency — and hire me first to make sure the data they are targeting is real. I frequently work alongside an agency rather than instead of one, and I have no interest in replacing a team that is performing.
- Where the two overlap
- Flow architecture, segmentation logic and deliverability sit in the middle. They need marketing judgement and technical execution at the same time, which is exactly where handoffs between an agency and a developer break down. This is the work I would rather own end to end.
- SMS marketing on Shopify
- Klaviyo SMS with compliant collection, double opt-in where the jurisdiction requires it, quiet hours, carrier filtering rules and a cadence that does not exhaust the channel in six weeks. SMS earns far more per send than email and burns far faster if it is abused, so it gets built with tighter exclusion logic than any other channel.
- Migrating into or out of Klaviyo
- Mailchimp, Omnisend, Attentive, Postscript or a legacy ESP into Klaviyo with consent status, engagement history and suppression lists preserved — losing the suppression list is how a good sender reputation dies on migration day. I also do the reverse honestly: if Klaviyo is genuinely oversized for your volume, I will say so.
How a Klaviyo engagement runs
- 01
Account audit
I review flows, segments, deliverability, integration health and the last 90 days of revenue attribution. You get a written report showing exactly where owned-channel revenue is leaking and what each fix is worth.
- 02
Fix the data layer first
Before writing a single email I make sure events fire correctly, identifiers stitch across sessions and the Shopify integration is passing everything it should. Flows built on broken data just automate the mistake.
- 03
Build and launch flows
Flows go live in priority order — usually cart and checkout abandonment first, since that is the fastest payback — each one live-tested with real orders and a test profile before it is switched on for your list.
- 04
Measure and iterate
Monthly review of flow revenue, deliverability and list growth, with A/B tests on subject lines, timing and offers. Retainer clients get a running backlog we reprioritise together based on what the numbers say.
Klaviyo expert FAQ
How much does Klaviyo cost per month?
Klaviyo's own pricing is by active profile and send volume, and it starts free up to a few hundred profiles. The number that matters more is the ratio: Klaviyo's list-based pricing means a bloated list of people who never open anything is a bill you pay every month for nothing. Cleaning and sunsetting dead profiles routinely cuts the subscription cost and lifts deliverability at the same time, which is why list health is one of the first things I audit. My own fees are separate from the platform fee and are described below.
What does Klaviyo work cost?
A full account audit with a written action plan is a fixed fee starting around US$500. Building a complete core flow set typically runs as a project quoted from that audit. Ongoing campaign and optimisation work is a monthly retainer. My hourly rate for ad-hoc Klaviyo development is US$60 to US$90, and you always see the number before work starts.
You are in Brazil — can you work with my US marketing team?
Yes. I am in São Paulo, UTC-3, one to two hours ahead of US Eastern, which leaves four to six hours of live overlap with a US business day. Campaign sends are scheduled in your customers' time zone, not mine, and I am on WhatsApp for anything time-sensitive around a launch or a sale.
Do you sign an NDA before touching my account?
Always. Every engagement runs under a written contract covering confidentiality, scope and IP, and I am happy to sign your NDA or MSA. Customer data is sensitive: I work through a Klaviyo user account you create and control, with the minimum role required, and I never export your list.
Who owns the flows and templates you build?
You do. Everything lives inside your own Klaviyo account, and template code, custom integration code and documentation are assigned to you in the contract. If you move to another agency there is nothing to migrate and nothing to unlock — it is already yours.
Klaviyo or something cheaper?
For a Shopify store doing real volume, Klaviyo's native integration and segmentation are worth the price difference, and cheaper tools usually cost more in engineering time to reach the same place. That said, if you are pre-revenue or sending to a very small list, I will tell you to wait rather than sell you a build you cannot use yet.
Can you fix an account someone else set up?
That is most of my Klaviyo work. Inherited accounts usually have overlapping flows, stale segments, broken integration events and a sending reputation nobody has looked at. I map what exists before changing anything, keep what works, and document every change so your team can follow what happened.
Want your owned channels to actually earn?
Send me your store URL and roughly what Klaviyo is doing today. I will tell you where the money is sitting — free.