10 Best Product Design Agencies for Series B AI Startups - August 2026

How we picked these agencies

Five checks, sized for a company with real customers and a product that has outgrown its own structure:

1. Platform depth. Is the practice built around product and interface work, or around websites with a product service beside it? At this stage the expensive problems are inside the application: navigation, permissions, settings, and the parts nobody has redrawn since the first version. A studio strongest at marketing pages will do good work on the wrong half.

2. Proof at scale. Have they worked on a product that already had users when they arrived? Designing something new is a different job from restructuring something people depend on. The second one requires a plan for shipping change gradually, and a view on what can be moved without breaking a habit.

3. Pricing. Is a starting figure public, or does it require a conversation? At Series B there is usually a procurement step and a comparison to write, and a published number saves a week of scheduling.

4. Team shape. How large, and who is actually on the work? A larger studio can staff a long engagement, which you may need. It also means the senior person who won the project may not be the one making daily decisions, and at this stage those decisions compound.

5. Their own site. Nobody made them compromise on it. If it states a position clearly and recently, that is a studio capable of helping you restate yours, which after a Series B usually needs doing.

The second check deserves the most weight. Test it by asking how they last rolled out a structural change to an existing product. A studio that has done it will describe a sequence: what shipped first, what was left alone, how the change was explained. A studio that has not will describe a launch.

The tables here are built from what each studio publishes about itself and nothing else. No directory profiles, no review aggregates, no filled-in guesses. An empty row means the studio has not said, which is a fact worth having rather than a gap to paper over.

What goes wrong when Series B companies redesign

Three failures, and none of them look like failures while they are happening.

The product grew by addition and nothing was ever removed. Every quarter added a surface, because adding is fast and removing needs a decision. Now there are two places to change a setting, three ways to start the same task, and an onboarding flow trying to introduce all of it politely. The instinct is to redesign the navigation. The actual work is deciding what the product does not do any more, which is a leadership decision that a design team cannot make on its own and should not be asked to.

The in-house team becomes a request queue. Two or three designers were hired, and they are good. They are also the only people who can produce a screen, so every team routes through them, and their week fills with small work. No component set gets built, no structural question gets answered, and the backlog grows in a way that looks like understaffing but is not. An outside team is useful here precisely because it can be given the structural job that the internal queue will never reach.

Enterprise requirements arrive as separate features. Single sign-on, roles, permissions, audit logs, and admin reporting each turn up as a deal blocker, and each gets built by whichever team had capacity. The result is five admin surfaces that behave differently, which the customer discovers during their security review. Design them as one surface the first time it comes up, even if only two of the five ship, because retrofitting consistency across them later costs more than building it once.