Interaction Design (IxD) Services

Interaction design services decide what a product does the moment a person acts on it, and how it behaves across every state that follows: what it asks, what it already knows, what it does on its own, and what it hands back. It is the behavior layer, which sits between the task a person is trying to finish and the screen that carries it. Vivaldi has worked on brand, product and experience design since 1999.

• Since 1999brand, product and experience design work
• 200+published case studies
• 10 officeson four continents
• 5xWirtschaftsWoche Best of Consulting, Strategy and Innovation

Most products that frustrate people are not ugly. They are correct, consistent, nicely rendered, and they behave badly: they forget, they ask twice, they go silent while something runs, and they act without saying what they just did. That is an interaction design problem, and it is rarely solved by another visual pass. This page covers when the behavior layer is the real constraint, what our interaction design services include, where this discipline stops and UI, UX and CX design begin, and how to evaluate any firm selling it.

One disambiguation first, because the names collide on our own site. This page is about the craft discipline of designing how software behaves. It is not interaction field modelling, which is our business model work on value exchange among many participants in a market. Same word, different subject.

When companies bring us in

The brief almost never arrives labeled interaction design. It arrives as one of these.

• A redesign shipped, the screens are better, and the same complaints about the product being tedious came back within two quarters
• One flow has an abandonment rate nobody can explain from the analytics, because the problem is a state the funnel does not record
• Several squads each own part of the same journey, and the product behaves like four products in one shell
• An automated or AI-driven feature was added, and nobody has decided what it does without asking, what it asks about first, or how a user takes it back
• The design system is immaculate and the product still feels slow, because the latency, empty, error and partial states were never designed at all

Why another visual redesign does not fix it

The standard argument for redesigning is reasonable: interfaces accumulate clutter, the brand moves on, and periodic renewal is maintenance. That is true and it is not usually what is wrong.

What is wrong is that behavior is decided by default. Nobody writes down what the system should do when a user is halfway through and leaves, when data is late, when a confidence score is low, or when two features both want the screen. So each of those gets answered separately, inside whichever ticket surfaced it first, by whoever happened to be building that week. The result is a product that is visually one thing and behaviorally several.

• Defaults that were set by a database schema rather than by a decision about what most people want
• Confirmations on the harmless actions and no confirmation on the destructive one
• A system that remembers what the user typed in one place and not in the next, because the two were built by different teams
• Automation that acts correctly and never explains itself, so people stop trusting it and work around it

None of that is a rendering failure. It is a set of decisions that were never made, and a visual redesign re-renders them rather than resolving them.

Where interaction design stops and UX, UI and CX design begin

These four get sold interchangeably and they answer different questions. It is worth being plain about which you are buying.

• User experience (UX) design settles the structure of the task: what the person is trying to get done, the path they take, and what is removed from it.
• Interaction design settles what happens when they act on that path, and how the system responds over time: states, defaults, feedback, memory, recovery, and what the product does on its own.
• User interface (UI) design settles what the thing looks like and how its controls are laid out: components, hierarchy within the screen, type, color.
• Customer experience (CX) design settles the whole relationship across channels and over time, most of which no interface touches.

The short version: UX decides the path, interaction design decides the behavior along it, UI decides how it looks, CX decides the relationship around it. Most engagements need more than one. The order is what matters, because a beautifully rendered set of behaviors nobody chose is the most expensive way to be consistent.

What our interaction design services include

1. Behavior audit of the flows that carry the decision

We walk the product the way a user meets it, including the paths that only appear when something goes wrong. The output is an inventory of the states that exist, the states that should exist and do not, and the places where the system behaves differently in two parts of the same journey. Support tickets and session data point at where to look; the audit says what the behavior actually is.

2. Interaction principles and behavior standards

A short set of rules that settle the recurring arguments once rather than per squad: what gets confirmed, what is undoable instead of confirmed, what the system remembers between sessions, what it does while it waits, how it reports partial success. These are the decisions that make a multi-team product feel like one product, and they are cheap to agree and expensive to retrofit.

3. State and flow design for the interactions that matter most

For the flows worth the investment, the full behavior: entry, progress, interruption, latency, empty, error, partial and recovery. This is the part most often skipped, and it is the part users spend their difficult minutes in. The work is done as decisions and flow definitions, in a form a design and build team can take into production.

4. Designing behavior for systems that act on a user’s behalf

When a product only presents information, interaction design is a clarity problem. When it acts, three harder questions arrive: what it does automatically against what it asks about first, how it communicates confidence so people calibrate trust instead of guessing, and how a person reverses something it already did. These are governance decisions in design clothing, and they need product, legal and commercial owners in the room, not just designers.

5. Handover, ownership and the exceptions that follow

Behavior rules decay the moment the first case they do not cover arrives. We write the decisions down in a form your team can implement against, and we agree who arbitrates the exceptions after we leave. Production of the interface itself sits with your design and engineering teams, or with the UI design and prototyping and testing work alongside this.

How an interaction design engagement works

1. Frame. Interviews with the people who own the product and the people who support it, a review of the analytics and support data, and a walk through the current flow as a user meets it, failure paths included. The output is a short list of flows worth the work and the behavior decisions blocking them.
2. Decide. The principles and standards: what is confirmed, what is reversible, what is remembered, what happens while the system waits, what it does without asking. Agreed with product and commercial owners, because most of these are trade-offs rather than preferences.
3. Design and test. The behavior for the priority flows across all their states, put in front of real users at the fidelity the open question requires, with the measure of success agreed before the session rather than after it.
4. Hand over. Documented behavior your build team can implement without re-litigating it, the rules that govern the next flow nobody has drawn yet, and a named owner on your side for the exceptions.

Why companies choose Vivaldi for interaction design

Three reasons, and one honest limit.

• We treat behavior as a business decision. Whether a system acts on its own, what it remembers and what it makes reversible are commercial and risk choices before they are design choices. We run them with the people who can actually settle them.
• We work upstream and downstream of the screen. The same team works on the product strategy and the task structure, so a behavior rule can be traced back to what the product is for rather than to a style preference.
• We write for the team that stays. The deliverable is decisions your organization owns, not a file our agency owns. If the rules live only with us, your consistency has a renewal date.
• The limit: we are a strategy and design firm, not a production studio. We do not staff front-end implementation or motion production. We work alongside the teams that do, and we say so at scoping rather than at handover.

How to evaluate an interaction design consultant

Worth asking of every firm on your shortlist, including us.

• Ask them to describe a state you did not mention. Anyone can design the happy path. The test is whether they immediately ask about latency, partial failure and what happens when a user leaves halfway.
• Ask where interaction design ends for them. If the answer is the screen, you are buying UI work under another name, which is legitimate and is a different purchase.
• Ask who signs off a behavior rule. If the answer is the design lead alone, the rules will not survive their first collision with legal, risk or a revenue target.
• Ask how automated behavior is bounded. Scope, escalation and reversal are design decisions where a system acts for someone. A firm that has not thought about them will show you a demo rather than a product.
• Ask what happens to the rules after handover. Who arbitrates the first exception, and where the decision is recorded. Without an answer, you have bought a document.

Interaction design consultancy vs digital product agency vs in-house product team?

Related work

Interaction design is one layer of a larger design practice. These are the adjacent engagements, and the question each one answers.

• Service design consulting if the behavior extends past software into what people and operations do.
• User experience (UX) design if the structure of the task itself is the constraint.
• User interface (UI) design if the behavior is settled and the screen is what needs work.
• User insights and research if you do not yet know which behavior is costing you.
• Prototyping and testing if a specific behavior needs evidence before it is built.
• Customer experience (CX) design if the problem spans channels rather than one product.
• Digital product creation if the product itself does not exist yet.
• Interaction field modelling if the real question is which participants create value for each other, rather than how your software behaves.

This work sits inside our Brand, Innovation and Experience practice at Vivaldi.

Interaction design services in the US and worldwide

We work with product and design leaders from 10 offices on four continents, including New York, London, Dusseldorf, Munich, Zurich, Hamburg and Shanghai. Behavior decisions travel badly between markets without being written down: what counts as a reasonable default, how much confirmation feels respectful rather than obstructive, and what automation is acceptable without asking all differ by region and by regulation. Engagements that cover several markets settle those differences explicitly rather than discovering them in local release notes.