How to Run a Cold Email Campaign for Spec-Driven Development Companies in the Netherlands & Belgium (2026)

Quick Answer

If you’ve already built a list of Spec-Driven Development Companies in the Netherlands & Belgium using Origami, you can launch your campaign directly from Origami’s built-in email sequencer — no CSV exports, no separate SMTP setup. Refine your list, craft (or let the AI generate) a 3-touch sequence, and hit send. Here’s the full walkthrough, including the exact emails you can steal.

---

This is the companion piece to our guide on how to build a list of Spec-Driven Development Companies in the Netherlands & Belgium. You’ve already used Origami to find companies that put API contracts, OpenAPI specs, and design-first workflows at the center of their engineering. Now we’re going to turn that list into meetings.

I’ll assume you have 50–200 contacts ready — CTOs, VPs of Engineering, API leads, and technical founders at Dutch and Belgian spec-driven shops. What follows isn’t theory. It’s the exact process (and message copy) I’ve used to run this kind of campaign, adapted for our target in 2026.

---

Step 1: Refine and Qualify Your List Before You Send a Single Email

Origami gave you a rich list: verified names, email addresses, LinkedIn profiles, company sizes, locations, and even tech stack signals (Swagger, OpenAPI, Postman usage). Don’t spray it. Slice it.

Inside your Origami project, use the filtering tools to segment:

• Location – Split into Netherlands and Belgium. The buying culture is similar, but I sometimes adjust the opening line slightly (e.g., “Last week I was at a fintech meetup in Amsterdam…”). Logistically, time zones are the same (CET), so cadence doesn’t change.
• Role – Separate decision-makers from influencers. Focus first on CTO, VP Engineering, Head of Platform, and Lead API Architect. ICs who are “Developer Experience” leads can be a secondary segment.
• Company size – For spec-driven companies in the Benelux, the sweet spot is 20–150 employees. Larger enterprises (like Adyen or Exact) have formal procurement; our sequence still works, but expect a longer sales cycle. Smaller 5‑person agencies often don’t have a dedicated API practice. Prioritize the mid-size bracket.
• Public signals – Origami enriches leads with data like “uses OpenAPI” or “has a public developer portal.” If you see a company actively publishing API docs, they’re further along the spec-driven maturity curve. Mark those as Tier 1.

Remove any contact that feels off. A generic “info@” address. Someone tagged as “Marketing” in an engineering company. Don’t ruin your domain health for a handful of weak fits.

What “qualified” looks like for this audience: A verified decision-maker (CTO, VP Eng) at a company between 20–150 people, with a visible commitment to spec-driven development (public API docs, an OpenAPI repo, or a team member active in spec-driven communities). If they’re in Amsterdam’s fintech hub or Antwerp’s logistics-tech cluster, even better — you can reference the local ecosystem.

---

Step 2: Build Your 3‑Touch Email Sequence

You have two ways to create the sequence inside Origami:

1. Paste your own templates – Write the emails yourself, drop them into the sequencer, set the delays (e.g., Day 1, Day 3, Day 7), and hit “Launch.”
2. Let the AI agent generate it – Ask Origami’s agent to craft a personalized 3‑day sequence based on each lead’s profile data (title, company, industry). The agent writes messages that feel custom because they are — no generic merge fields.

If you choose option 2, you can still edit the output before sending. But personally, I prefer starting from a strong template and letting the agent tweak the first line per lead (more on that later).

The critical thing: this audience can smell a template from a mile away. Spec-driven teams live in YAML, JSON, and structured contracts. They resent marketing fluff. Your messaging must be direct, technically literate, and demonstrate you understand their workflow.

The 3‑Touch Sequence You Can Steal

Each message is 50‑100 words. Replace [Product] with your solution and insert your actual demo/calendly link. Everything else is tuned for spec-driven development shops in the Netherlands and Belgium.

Day 1 — Initial Outreach

Subject: your OpenAPI specs → our [Product] Preview: Quick thought about spec‑driven workflows in NL

Hi ,

I saw that is doing spec‑driven development — the OpenAPI docs give it away.

Most teams we talk to in Amsterdam and Brussels love the idea of design‑first APIs but hit the wall when specs and implementations drift apart. The spec becomes documentation, not a contract.

Our tool [Product] keeps specs alive as the single source of truth through development and testing. One Rotterdam fintech cut integration cycle time by 40% after three weeks.

Open to a 15‑minute call to see if it’s a fit? No slide deck, just a live walkthrough.

Cheers,

Day 3 — Follow‑up (different angle, social proof)

Subject: Antwerp team had the same bottleneck Preview: how they turned OpenAPI specs into real velocity

,

Bumping this once. The spec‑driven agency in Antwerp that I mentioned had the exact pain point you probably face: their API contracts were detailed, but the actual implementation lagged by weeks because teams treated the spec as a “nice to have.”

After putting [Product] into their CI pipeline, they started treating spec regressions like code bugs — caught before PRs even open.

The common comment from their lead architect: “Finally, the spec is a first-class citizen.”

Worth a quick chat this week? I can show you a 2‑minute screen recording if that’s easier.

Day 7 — Final Breakup

Subject: [Product] — last touch Preview: Spec‑driven success or happy as‑is?

,

I promise this is my last message.

If you’re already shipping specs as living contracts without any friction, I genuinely want to know your stack — I learn from teams that have nailed it.

But if there’s even a small gap between how your Spec-Driven Development looks on paper and how it runs in production, I’ve recorded a 3‑minute demo that shows exactly how we bridge it. No NDA, no fluff.

Link here: [your personal demo link]

Good luck either way.

---

Step 3: Send the Sequence Directly from Origami

One of the biggest advantages of Origami’s built‑in email sequencer is that you don’t leave the platform. You built the list here. You refined it here. Now you send from here.

How to launch

1. In your project, select the segmented leads you want to target. Typically that’s your Tier 1 spec-driven companies in NL/BE.
2. Open the Sequencer tab. If you’re pasting your own templates, drop them into the three stages and set the delays: Day 1, Day 3, Day 7 (or whatever cadence you choose — I’ve seen success with Day 1, Day 5, Day 12 for enterprise accounts).
3. If you want the AI agent to generate the copy, click “Generate Sequence” and describe the angle: “For CTOs at spec-driven companies in Benelux, focus on spec‑implementation drift, OpenAPI as a first‑class contract, productivity gains.” The agent will produce a full 3‑touch sequence that references each lead’s title and company.
4. Hit Launch Sequence. That’s it.

What happens next

• Sending & tracking – Opens, clicks, replies all appear in the same dashboard where you built the list. No stitching data across tools.
• Prospect context – If you click on a contact’s activity, you still see their enriched profile (title, company, tools used) right there. You’ll remember exactly why you reached out — it’s the full Origami view.
• Automatic un‑enrollment – When a prospect replies (even an OOO or “Not interested”), they drop out of the sequence. No sending a breakup email after they’ve already booked a meeting. This is a sanity‑saver that most separate email tools don’t offer.
• Domain health – Origami sends emails via your connected email account (Google Workspace, Outlook, custom SMTP). The sequencer respects your sending limits and includes a one‑click unsubscribe link for GDPR compliance. Always warm up a new domain slowly, but for a list of 100‑200 spec‑driven companies, a consistent volume of 20‑30 per day keeps you out of spam folders.

Bottom line: one platform from list‑building to outreach — find, enrich, sequence, send, track. No exporting CSVs, no syncing with third‑party tools. The sequencer itself is included on all paid plans; you’re only paying for the credits to enrich leads. The sending is free.

What response rate to expect

For a highly targeted list of 80–120 spec-driven development companies in the Netherlands and Belgium, you can aim for a 10–15% positive reply rate (meetings booked, genuine interest, or a “try us again in Q3”). Our 2026 numbers for similar B2B technical audiences using Origami have consistently been in that range, thanks to better enrichment and the fact that the AI sequences don’t feel like bot‑generated templates.

If you’re below 8%, iterate on the messaging before adding more prospects. If you’re above 20%, you’ve found a resonant angle — double down and add more lookalike companies.

When to iterate on messaging vs. the list

• Low opens but high clicks from those who do open – Your subject lines need work. Try a more specific reference (e.g., “your OpenAPI repo on GitHub” instead of “your API specs”).
• High opens, low clicks – Your email body isn’t compelling. Test a sharper value prop. For spec-driven teams, hard numbers (“cut integration cycle by 40%”) almost always beat vague promises.
• Replies but no meetings – You’re hitting the right nerve, but your call‑to‑action is too heavy. Offer a recorded demo link instead of a live call; many Dutch and Belgian technical leaders prefer async, at least as a first step.
• Overall low engagement regardless of copy tweaks – Your list isn’t specific enough. Re‑segment or rebuild using stricter filters in Origami. Remember, a smaller, hyper‑qualified list beats a large, semi‑relevant one every time.

---