How to Build Integrations Your Customers Will Love

Building integrations your customers love doesn't start with the build.

Before a spec is written or an engineer is looped in, the most successful teams have already done the hard work of understanding who they're building for, what the data actually needs to do, and whether an integration is even the right answer. The teams that struggle usually skipped that part. They moved fast, shipped something, and then watched adoption flatline.

If you're still making the case internally for why integrations matter in the first place, this is a good place to start. If you're past that and ready to build, here's how we approach integration design from the ground up.

Natalie Petruch Trent, product manager at Pandium, ran a workshop on applying a design thinking approach to integration development. She's spent almost a decade on integrations across implementation, CX, and product management. What follows is a detailed breakdown of her recommendations on how to build integrations your customer will love.

Know What Kind of Integration You're Building

Not all integrations are created equal. On one end, you have lightweight syncs. Zipping data in one or two directions, minimal configuration, nothing fancy. On the other, you have something like NetSuite or Salesforce, where every customer's account looks completely different and the configuration options run several layers deep.

The instinct is to treat complex partner integrations as necessarily fully custom builds. They don't have to be. In our experience, almost any integration can be built generically with robust configuration options layered on top. We'll come back to that, but it's a frame worth holding onto from the start.

Start With the Big Questions

Before a spec doc, before engineering, there are two sets of questions that need answering.

The first is macro. Why do you need this integration now, specifically? What business goal is it actually serving? If you're trying to move upmarket, the integration requirements look very different than if you're trying to stop churn in your existing base. Knowing that before you start shapes every decision downstream.

The second set is more granular. Who exactly is this for? Admin users or the people using the product every day? Internal teams or external customers? And the question that gets skipped most often: would building this integration actually solve the problem? We've seen teams hear "we need a QuickBooks integration" and spend months scoping and building, only to realize the real gap was something their own product could have handled with a bit more investment. An integration is one solution. It's not always the right one.

Also worth settling early is whether your own product's API can even support what you're imagining. You can't sync accounting data into a platform that has no mechanism to receive or display it. Obvious in theory. Surprisingly easy to miss in practice.

Talk to Three Groups, Not One

Most teams talk to users and call it research. What they're missing is two other conversations that matter just as much.

Internal stakeholders first. Your CEO, CTO, and CX team all have goals the integration needs to hit, and getting those on the table before you write a single use case saves a lot of revision later.

The partner relationship is the one we see skipped most consistently. Companies pull the public API docs and start building, which is a mistake. Public API documentation is written for individual, single-instance use cases. Building something that needs to work reliably across 50 different customers is a different problem entirely, and the protocols, edge cases, and support structures that come with it rarely show up in the docs. Developing that relationship early surfaces information you won't find anywhere else. And if there are missing API endpoints standing between you and what you need to build, having a real contact at the partner company makes it possible to raise that and actually get it resolved.

Then there are users themselves. Schedule interviews. Pull notes from existing sales calls. If you have churned customers you still have a relationship with, talk to them. Use open-ended questions because "what information do you need moving back and forth?" gets you a lot more than "do you need a transaction flow?" People describe the same underlying need in a dozen different ways, and hearing that range is the point.

One of our favorite questions to ask in any research session is what we call the pie-in-the-sky question. No constraints on time, money, or technical feasibility. Just ask what they would want if nothing were off the table. It gets people past describing only what they think is achievable, and the answers are almost always useful even when they're not immediately buildable.

Screen sharing is underrated here too. Watching someone walk through their actual workflow tells you things they'd never think to articulate in a conversation. It also forces you to become genuinely fluent in the partner product, which you'll need to be at some point anyway.

Don't forget your existing feature request backlog either. Requests that don't explicitly mention integrations can still be pointing at the same gap. "I wish we had a better way to manage transactions" might be the same ask in different language. Think broadly first, then distill.

Distill, Group, Prioritize

Once you have all the feedback, the work becomes sorting it. Pull out everything potentially relevant, set aside what clearly isn't (move it, don't delete it), and then look for clusters in what remains. Five different users independently describing a need for better transaction visibility is a signal. 

From there, prioritize by volume of signal and then layer in engineering effort. The number of requests matters but it can't be the only input. Something requested frequently that would take six months to build deserves a very different conversation than something requested frequently that would take two weeks. We put together a prioritization template to help with this step if you want somewhere to start. Bring your tech team in before you finalize scope.

Design the Data Flows Before You Write a Line of Code

Every use case becomes a user story first. "When I create a new transaction in QuickBooks, I expect to see it in Acme Co." Simple as that. Then you figure out what data needs to move, in which direction, and how often.

Start with triggers. Is this webhook-based, polling-based, or both? A few things to nail down here before moving forward:

• Webhooks give you real-time updates but they're not perfectly reliable. If you're using them, build in a polling component to catch what gets missed.
• Frequency needs to be set at the data flow level, not just for the integration as a whole. One flow might run every hour. Another might need to run every 15 minutes.
• For two-way syncs especially, establish which system is the authoritative source of truth for each data point early. If that isn't documented clearly from the start, you'll be untangling it mid-build.

Field mapping is usually where the surprises show up. Go through the API documentation for both products and map every field you need. Gaps will appear, and a field that's critical in your product may have no direct equivalent on the partner side. When that happens, your options typically look something like this:

• Create a custom field on the partner side to hold the data
• Find an alternative field that can carry the information with some reformatting
• Build a workaround into the integration logic itself

Finding any of these out before the build starts gives you options. Finding it out mid-build gives you a problem. Keep a dedicated section in your documentation specifically for these oddities.

Rate limits and system constraints are the last piece before you go to engineering. If your integration will run frequently or handle high volume, you need to know what the API will actually tolerate. Can you batch requests? Use concurrency? Pull your tech team into this conversation even if you don't need them for anything else yet.

All of this lives in a scope doc first, then a spec doc. The scope doc goes to engineering. The spec doc is the living document that tracks everything through development, QA, and beta. We have a spec doc template here if you want a starting point. Tip: write it expecting it to change.

Keep Your MVP Tight

Here's a rule of thumb we come back to often. A simple integration should take no more than two weeks to build for the first iteration. For something complex like NetSuite or Salesforce, three months is the ceiling for V1. Going beyond those timelines is almost always a sign that the MVP has grown too large, not that the timeline is too short.

Strip it back to the one thing users cannot do without. Ship that. Get it in front of real people, watch what happens, and build from there.

On configuration, the better long-term play is building one generic integration with real configuration options baked in. Let customers toggle individual data flows on and off. Let them set their own field mappings rather than relying on static ones. Give them control over sync schedules. Building this way takes more thought upfront, but it means you're maintaining one solid integration rather than ten custom ones that all need to evolve separately.

Don't Skip Beta

QA catches the edge cases you anticipated. Beta catches everything else.

Start building your beta list before the build is finished. If you have a marketplace or a mailing list, put up a "coming soon" page and let people raise their hands. Reach out proactively to customers who've mentioned the integration in sales calls or support tickets. You want a pipeline of real users ready to go the moment the build is done, not a last-minute scramble to find them after the fact.

Run two copies of your QA template. One internal, one external. If your partner wants to run their own validation, give them a version. If beta users are involved in testing, give them one too. The format doesn't need to be complicated. Steps to follow, what they did, whether it passed or failed, notes on anything unexpected.

One thing that consistently gets overlooked is the install process for end users. Not just the integration itself, but the setup. Provisioning steps, API key retrieval, any unusual permissioning (NetSuite's is notoriously complex). Have someone on your internal team go through the setup from scratch and note every point of friction. Those friction points are your documentation priorities. Include a gotchas section covering common errors with plain-language explanations of why they happen. Your CX team will use it constantly, and so will your customers.

The Work Before the Integration Build

The integrations that customers actually love and keep using succeed because someone did the unglamorous work first. Talking to the right people, asking the right questions, mapping the data flows before writing a line of code, and keeping scope tight enough to ship something real.

None of that is complicated, most of it just requires slowing down at the beginning so you're not cleaning up the mess at the end. The teams we've seen get this right consistently share one habit, they treat the design and research phase as seriously as the development phase. Give yourself a solid foundation for everything else to sit on.

If integrations are influencing your roadmap or your revenue, we'd love to talk. Our services team works directly with companies to scope custom integrations. Book a time to chat.