How to Build Your Own CRM and Marketing Automation Stack
Build a CRM and marketing automation stack that suits your business. Learn which tools you need, what it costs and how to connect them, step by step.
A CRM and marketing automation stack is the set of connected tools that stores your customer records and sends the right message at the right time. Building your own means choosing each tool for its job and connecting them, which can give a growing business more control at a lower monthly cost than one large all-in-one platform.
I recently set one up for a B2B SaaS client preparing for a relaunch, using the CRM they already had and a separate platform for their email sequences. This guide follows the same process, with the decisions we made and the order we worked in.
What goes in a CRM and marketing automation stack
Layer | What it does | Examples |
|---|---|---|
CRM | Holds every contact, company and deal | |
Messaging platform | Sends email sequences, plus SMS or WhatsApp if you need them | |
Data source | Shows what customers are doing | Your product, online store or booking system |
Connections | Move data between your tools | Built-in integrations, APIs, n8n |
Reporting | Shows what’s working | GA4, CRM dashboards |
Three ways to set it up
An all-in-one platform such as ActiveCampaign or Brevo gives you your CRM and messaging in one place. It’s a great fit for small teams with straightforward campaigns, because there are fewer tools to look after.
A connected stack pairs a CRM with a specialist messaging platform. This suits businesses that want messages triggered by what people do, such as a software company guiding new users through a free trial.
A custom-built CRM is designed around your exact process, using a workflow tool such as n8n or code written for you. It suits businesses with unusual processes and someone technical to maintain it, since you’ll also be looking after the hosting, security and data yourself. Most growing businesses will get further by starting with an off-the-shelf CRM and adding custom automations around it.
My client weighed up all three. They chose a connected stack, keeping HubSpot as the sales record and adding Customer.io for sequences, which gave them behaviour-based automation without moving up to HubSpot’s higher tiers.
What a CRM and marketing automation stack costs
Prices change often, so check the current figures before you decide. As a guide, HubSpot’s workflow automation starts at its Marketing Hub Professional tier, reported at US$890 a month on annual billing with a US$3,000 onboarding fee as at April 2026. HubSpot Starter was reported at US$20 per seat a month on monthly billing, and Customer.io’s Essentials plan starts at US$100 a month with 5,000 profiles and one million emails.
On those figures, a one-seat connected stack starts at around US$120 a month. It’s also worth budgeting for setup, because someone technical will need to connect your product and your tools. Costs will rise as your contact list grows, so run the numbers at the size you expect to reach.
How to build your stack, step by step
1. Map the journey you want to automate
Choose one journey to begin with and write down what should trigger each message. For a software trial, that might be a welcome series, a nudge towards the first useful action and an upgrade prompt. One well-mapped journey will show you exactly what your stack needs to do.
2. Choose your CRM and keep it simple
Make the CRM the one place your team goes to see a customer. We kept the HubSpot setup deliberately small, with eight custom fields covering trial dates, product activity and plan. That way it stays the sales record, and the messaging platform handles the sequences.
3. Prototype your first emails
Real emails make decisions much easier than a feature comparison. I had Claude build a welcome series in Resend and send it as a test, which gave the founders something real to react to before we had settled on a platform.
4. Set up your sending domain
Send from a subdomain such as mail.yourbusiness.com, so your campaigns stay separate from everyday company email. Then add the SPF, DKIM and DMARC records your platform provides, which help inboxes trust your messages. Find out early who has access to your DNS settings, because this is where builds like this tend to wait.
5. Send events from your product
Events tell your messaging platform what each person has done. We specified about ten, including:
Trial started
First project created
First teammate invited
Plan selected
Demo booked
Email unsubscribed or bounced
From there you can add a simple score, with points for each useful action, to estimate how likely a trial is to convert. Agree the weights as a team and adjust them once real results come in.
6. Connect your tools in both directions
Product activity should flow into the CRM, so your sales team can see where each trial is up to from one screen. Unsubscribes and bounces should flow back too, which keeps every tool in step with what each person has asked for.
7. Build consent in from the start
New Zealand’s Unsolicited Electronic Messages Act covers commercial email and text messages, and it asks for three things: consent, accurate sender details and a working way to opt out. Add a clear opt-in for texts at signup and confirm your unsubscribe link appears in every commercial email. WhatsApp templates need approval from Meta, so it’s easiest to add that channel once your email series is running. This is general information, so check the details with your adviser.
8. Test the whole journey
Run every sequence on internal addresses before you switch it on, then ask a real user to go from sign-up through to their first useful action. You’ll see what arrives, when it arrives and whether the CRM updates as it should.
Where AI fits in
AI has made this kind of stack much more approachable for small teams. I use Claude to draft and build email sequences, so a marketer or founder can get a new version in front of them quickly. A person should still review every message before it goes live, especially anything that touches consent or pricing.
What to measure
Start with the numbers tied to your journey: how many new users reach the first useful action, how many trials convert and how many customers stay. Then look at the effect on customer acquisition cost, because good lifecycle marketing helps you get more from the people you’ve already paid to reach. A stack like this is also a natural part of a go-to-market strategy for a launch or relaunch.
Common questions
Can you build your own CRM?
Yes. Workflow tools such as n8n and AI coding tools make it more achievable than ever. It pays to weigh that against the ongoing work of maintaining it, and most businesses will be well served by an existing CRM with automations added around it.
What’s the difference between a CRM and marketing automation?
A CRM stores your customer and sales information. Marketing automation uses that information, along with what people do, to send messages at the right moment.
When should a business set this up?
It’s worth doing once you have more leads or trial users than you can follow up by hand, or when you’re about to launch and want every new customer to get a consistent experience.
How long does it take?
It depends on your product and who’s available. For my client, the two platforms were set up and connected about a week after the decision was made, with product events to follow.
Your next step
If you’d like help choosing the right setup for your business, book a free 30-minute call and we’ll map it out together. I can also lead this work as part of a fractional CMO engagement.
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