9 min read
Choosing a digital product design agency: 10 criteria to evaluate before hiring
Hiring a design firm sets the direction for your product long after the contract ends. The right team ships work your users adopt and your investors notice. The wrong team leaves you rebuilding six months later, behind schedule and short on trust with your own stakeholders.
Approaching the choice between product design companies based on portfolio shots puts you in a position where you miss the things that matter the most: how a team handles a tight deadline, a stakeholder who changes direction mid-sprint, or a codebase that resists every design decision. Price sheets and case study decks look similar across the board once you've seen ten of them. What separates a team worth hiring from one worth passing on shows up in the details — how they answer a hard question on a call, how they structure a contract, how they talk about a project that didn't go as planned.
We built this list at Goodface agency after watching founders ask us the wrong questions. The right ones are below.
The ten criteria below dig past the visuals and show you how an agency actually works, day to day, decision by decision.
A design engagement that goes wrong costs more than the invoice.
A $40,000 project that goes wrong can end up closer to $100,000 once you add up:
the second project to rebuild what the first one produced
the market window you missed while the launch slipped
the hours your team spent managing work that wasn't going anywhere
the credibility you need to win back with your own stakeholders
Every extra month on a failing engagement means throwing good money after bad.
The market can feel overwhelming today. AI tools have lowered the barrier to producing visually competent design, which means more agencies can show you screens that look finished.
Fewer can show you screens that were tested against real users and tied to a number your business actually tracks. That gap is exactly what the ten criteria below are built to surface.
Case studies should show you how the team thinks. For every project that catches your eye, ask:
What problem did the project solve?
What did the team measure before and after launch?
What did the client get that their in-house team couldn't produce alone?
Pay attention to variety too. A digital product design agency that has only designed marketing sites will approach a complex SaaS dashboard differently from a team that has shipped multi-role platforms. Either one can be the right choice, depending on what you're building.
Ask for two or three references you can call directly, and set aside the time to actually call them. The most useful question is a simple one: what surprised you about working with this team, good or bad? An agency confident in its client relationships sends names and phone numbers within a day.
Few agencies can explain the process to you clearly in five minutes without opening a slide deck.
Ask them to map out a typical engagement for you:
what happens in week one, week four, and week twelve
which deliverables land at each stage
who approves each deliverable, on your side and on theirs
Ask what happens when research uncovers something that contradicts the original brief. Does the process bend, or does the team push forward on the original plan regardless? A rigid process that ignores new information usually produces a design that solves the wrong problem well.
Sales calls are often led by senior partners who never open a design file again once the contract is signed. Ask who designs, who codes, and who manages the account week to week. Get names and prior work samples, not job titles.
Find out how much of the work stays in-house and how much goes to subcontractors you'll never meet. A rotating bench of freelancers can work on a short engagement. On the other side, on a six-month project, it creates real risk, because continuity matters as much as skill.
A smaller senior team frequently outperforms a large agency that spreads junior staff across ten accounts at once. Team size doesn't guarantee results — direct accountability does.
Have a conversation about how often you'll hear from the team and through which channels. For most product teams, weekly calls combined with async updates in Slack or Notion keep the work moving. Monthly check-ins with no visibility in between slow a project down, and on a project tied to a launch date, those weeks add up fast.
Ask how the team records decisions. Without a written trail of why a flow changed or a feature got cut, the project gets hard to manage once new stakeholders join or people forget the details six weeks in.
Also ask how the team makes a call when there's no time to wait. If every question travels through three layers of approval, you'll feel it at the eleventh hour, right when your launch window starts closing.
When a design team hands static files to your engineers, it sets up a second project: rebuilding what was designed. Go over the handoff process in detail and check whether the team:
builds with real component libraries in Figma
writes specs your engineers can act on without a translation meeting
shares a working prototype for complex interactions, so developers don't have to guess
Strong agencies design with engineering constraints in mind from the first sketch — screen states, edge cases, responsive behavior, loading states — rather than adding them once the mockups look finished. Ask to see an example of a design file they've handed to an engineering team, and ask that engineering team's lead what the handoff was like.
Ten SaaS logos in a portfolio don't guarantee the right fit for a fintech product. Regulated industries, marketplaces, and platforms with layered permission structures each demand different design instincts. Ask how the agency approaches compliance requirements, data-dense interfaces, or multi-role dashboards if your product needs them.
An agency that asks sharp questions about your users and constraints during the sales call shows you how they'll operate once you're a client. Vague, generic questions on a discovery call usually predict vague, generic design work later.
Ask how design decisions get made. Does the team run user interviews, usability tests, or A/B tests before committing to a flow? Or do they design from instinct and call it finished?
A team that shows you a recording of a real usability test — a real user working through a real screen, hesitating at a confusing button — treats your product as a business problem worth investigating, not a visual exercise. Decisions backed by evidence hold up when a launch date gets tight and everyone's opinion starts competing for the final call.
Ask what they do when research contradicts a stakeholder's strong preference. The answer tells you whether design decisions in your project will follow evidence or follow whoever argues loudest in the room.
Design should connect to numbers your team already tracks: signup conversion, activation rate, support ticket volume, retention at day thirty. Ask how the agency defines success for a project and how they check results after launch.
Ask which metric moved on their last three projects, and by how much. A team that names a number measured it — and that habit carries into your work too. A team that answers only with adjectives, without a number behind them, likely never tracked the outcome at all.
The two common pricing models suit different kinds of work:
Fixed scope, fixed price fits a clearly defined deliverable, like a landing page or a design system.
Time and materials fits ongoing product work, where requirements shift as the team learns more.
Learn which model the agency defaults to and what happens when scope grows mid-project, because it usually does.
Ask where the agency draws the line between a revision and a new request, since that line causes more contract disputes than almost anything else. An agency that stands behind its process puts all of this on paper without pushback.
Timezone overlap, communication style, decision speed, and shared tooling decide whether a six-month engagement feels like a partnership or a grind. Ask how the agency handles disagreement with a client. Do they push back with reasoning drawn from research and prior projects, or do they design whatever gets approved fastest?
Ask how they've handled a client relationship that went wrong. An agency willing to describe a real misstep, and what changed afterward, tells you more than a polished answer about a flawless track record ever could.
A team that leads with reasoning builds products that hold up after launch. That's the kind of partner worth hiring again for the next release.
Red flag | What it signals |
Every project in the portfolio looks the same | Limited range, a template-driven approach |
No metrics or measurable results shown | The agency can't connect design to outcomes |
Sales team can't name who'll work on your project | Bait-and-switch staffing once the contract is signed |
No mention of user research or testing | Decisions are made on instinct, not evidence |
Vague answers about revision policy or scope changes | Disputes over cost and timeline later in the project |
No post-launch support offered | You're on your own once real users hit real problems |
Walk me through a project that went wrong. What happened, and what changed afterward?
Who will actually design and manage this project, day to day?
What does post-launch support look like, and what does it cost?
What would make you turn this project down?
Can I talk to a client whose project had real challenges?
Portfolio reviewed for process and outcomes
Two or three references checked, including at least one challenging project
Names and prior work confirmed for the people who'll actually work on your project
Communication cadence and documentation habits agreed in writing
Design-to-engineering handoff process explained and shown
Market or industry experience relevant to your product's constraints
Research methods confirmed: interviews, usability tests, or A/B tests
Success metrics defined and tied to numbers your team already tracks
Pricing model, payment schedule, and revision policy in writing
Fit confirmed through how the team handles disagreement and past mistakes
Before you sign anything, take each agency on your shortlist through these ten points. Give each one a score, then sit down with your team and compare notes. Along the way, pay attention to how each agency handles your questions.
If a team can walk you through its reasoning on a sales call, you can expect the same clarity three months in, when the deadline is close and a design decision has to be made fast.
Goodface saw in the practice that your choice of agency decides what users see the first time they open your product, and how much rework ends up on your engineers' plates. No checklist can promise a perfect match. These ten criteria will help you set aside the agencies that give a great pitch and fall short on delivery, so you can focus on the one that backs up what it says.
I'm Kerry. Content Writer at Shape – if you don't find me at my desk, I'm probably on holiday again 🌎✈️
