Product Builder

What Stackfix does

We help businesses cut costs and grow revenue with tailored AI. A factory processes orders by hand. A distributor loses deals because quotes take days. A fleet team copies information between systems.

We combine AI agents, proven software modules and custom development to reduce manual work, win more business and improve margins.

About us

Paddy worked at Google and founded Jukedeck, a neural-networks-for-music company acquired by TikTok. Tom founded and sold an HR software company in 2023 and has more than nine years of experience building AI systems.

We are backed by Seedcamp, Chalfen Ventures, TSIC and helloworld, with angel investors including Matt Clifford and Alice Bentinck, co-founders of Entrepreneur First, and engineers from DeepMind.

The role

You will spend most of your day speaking with customers: understanding their work, finding the real problem and helping them get more from the software we build.

You will also turn what you learn into better user experiences and working solutions, using AI on Stackfix’s system. You do not need to be a software engineer. You do need to think clearly, learn quickly and care about the details.

What you will do

• Understand the customer: run conversations, observe workflows and map how the work is done.
• Find the valuable problem: distinguish the immediate request from the underlying need, and prioritise improvements with a clear commercial benefit.
• Shape the experience: design user journeys, sketch interfaces, build prototypes and test them with the people who will use them.
• Build with AI: use AI on Stackfix’s system to turn ideas into working tools, then test and refine them.
• Work with engineers: explain customer needs clearly and collaborate on integrations, technical constraints and reliable delivery.
• Help customers succeed: demonstrate changes, support adoption, listen to feedback and keep improving the product.

A typical day

You might begin with an operations team, watching how they handle incoming orders and asking where work gets stuck. Later, you could test a simpler workflow with a customer, build a prototype using AI, and work with an engineer to prepare the next improvement.

Customer conversations are the largest part of the role. Building and UX work turn those conversations into something useful.

Who this role is for

• You are a clear, quick thinker who can make sense of an unfamiliar business.
• You are excellent with customers: curious, attentive and able to ask useful questions.
• You communicate precisely, in conversation and in writing.
• You notice confusing interfaces and care about making software easy to use.
• You enjoy trying AI tools, building things and learning through feedback.
• You take ownership and follow through, from the first conversation to a working improvement.
• You can show evidence of excellent work, whether in a job, a project, a business or another sustained pursuit.

This role requires at least one year of experience. No coding background or technical degree is required. Experience with customers, design or operations is useful, but we care most about how you think and what you can do.

What you get

• Real ownership: help shape what gets built and how customers experience it.
• Direct customer exposure: learn how businesses operate and see the impact of your work.
• Close collaboration: work with experienced founders and engineers in our Holborn office.
• Room to grow: develop your judgement across customer discovery, UX, AI building and commercial delivery.

This is a full-time, in-person role in Holborn, London, five days a week. We value autonomy, quality and sustained output.

Hiring process

1. 01

   Intro call

   Up to 30 minutes

   A conversation about your background, what you are looking for and the role.

2. 02

   UX screen

   Up to 30 minutes

   A focused discussion of how you approach user experience and understand customer needs.

3. 03

   On-site UX and customer interview

   1 hour, plus a walk

   Explore a customer problem and how you would make the experience better.

4. 04

   Paid work afternoon and lunch

   In person · 4 hours · Paid

   Work with us in Holborn and get a feel for the role and the team.

Right to work

You must have the right to work in the UK. We do not sponsor visas.