Building a parts procurement marketplace for commercial vehicle garages.
Gavin Diamond has spent over 20 years in the heavy goods vehicle (HGV) parts industry. He saw an opportunity to streamline how commercial vehicle garages procure parts—replacing fragmented, manual processes with a marketplace that connects buyers and suppliers.
The trouble was this: he needed a software product to go to market, but he didn’t come from a tech background. Even the concept of a “tech architect” was entirely new to him.
I helped Gavin plan the product blueprint for his parts marketplace, hired and managed a developer to build it, and then transitioned the developer to his team so he could continue building independently.
Here’s exactly how I helped Gavin build SpareDock.
“The big thing was I got an incredible product.”
— Gavin Diamond, Founder, SpareDock
Background
Gavin knew how fragmented and manual the parts procurement process was for commercial vehicle garages. He saw a gap in the market for a marketplace that could streamline the entire process.
He’d already built a smaller, low-touch version to test the theory and get user feedback. The concept was validated. Now he needed the real thing.
“I built a smaller MVP just to test the theory out, which gave us great feedback and confidence to build the go to market MVP.”
— Gavin Diamond, Founder, SpareDock
Problem: Gavin needed to build a marketplace, and he didn’t come from a tech background
Gavin had validated his concept with a smaller, low-touch MVP. The feedback confirmed the opportunity. Now he needed the real thing—a full marketplace built properly across buyer, supplier, and admin experiences. But he didn’t have a background in tech, and even the concept of a “tech architect” was entirely new to him.
Need 1: A working product he could take to market
Gavin needed someone who could take his industry knowledge and turn it into a real software product—a marketplace that could handle the full parts procurement workflow for commercial vehicle garages.
“I needed an architect that understood what I wanted to build, but also that I’m not tech savvy and was willing to hold my hand through the process to get a product that would fit the market at the end of it.”
— Gavin Diamond, Founder, SpareDock
Need 2: Real technical expertise he could trust
Gavin didn’t come from a tech background. He needed someone who understood how to build marketplaces and could challenge his assumptions and steer him in better directions—not just take orders.
Need 3: A clear scope and budget
This was a significant investment and would form the basis of his new software company. Gavin needed to know exactly what he was getting and what it would cost—and that scope changes wouldn’t blow up the project.
Need 4: A developer he could work with after his v1 launched
Gavin needed a vetted, reliable developer who could maintain and grow the product after the engagement ended—so he wouldn’t be left with software and no one to run it.
Why Gavin chose Kareem to build SpareDock
Two previous clients—Ciaran at Loadar and Joe at Bulki—independently recommended me. Gavin had spoken to one local company, but the referrals made it a “no brainer.”
“I thought we needed a local company to build it so I could go and see them and touch and feel the person. But then getting glowing referrals from other people that you worked with made working with you a no brainer.”
— Gavin Diamond, Founder, SpareDock
After two conversations, he knew it would work despite the distance between Northern Ireland and Canada. His initial fear—that someone remote would just take the money and disappear—was put to rest quickly:
“I wasn’t from a tech background, but I could see you were going to very much put me at ease through the process and hold my hand where it needed to be held, which you definitely did. It wasn’t going to be a case of ‘he’s going to take my money, give me a product and run.’”
— Gavin Diamond, Founder, SpareDock
He wanted someone who’d actually built marketplaces—not an agency
Software agencies make money by charging senior developer rates but paying junior developers to actually build the product. There’s no substitute for experience—most juniors at an agency simply don’t have the technical strength to build a solid foundation for a marketplace.
I offered Gavin my 20+ years of software development experience, including building a marketplace I grew to $130 million in volume. I didn’t know Gavin’s industry, but I’d spent almost a decade building marketplaces. I could challenge his assumptions and steer him in better directions when his ideas needed refining.
“You didn’t know the industry, but you clearly got marketplaces. You forced me to ask myself challenging questions. It wasn’t about firing jargon at me though — it was just very simplistic, put me at ease, and the questions you were asking made sense.”
— Gavin Diamond, Founder, SpareDock
He wanted a fixed price with a clear blueprint
Most software firms won’t give you a fixed price. They prefer to bill by the week or month because it shifts the risk to you—if the project takes longer than expected, that’s your problem, not theirs. For a non-technical founder making a major investment, that’s a tough pill to swallow.
I gave Gavin a fixed price for the entire build. To do that responsibly, I first produced a 52-page blueprint that spelled out every feature, screen, and user flow across the buyer, supplier, and admin sides of the marketplace. Gavin knew exactly what he was paying for and what “done” looked like before we started building.
He wanted a developer he could work with after launch
A common problem with agencies is that when the project ends, so does the relationship. You’re left with a product but no one who understands it. Gavin needed a developer who could stay on and grow the product with him.
I built the engagement around that outcome. I hired a senior developer, vetted him over several months during the build, and then transitioned him to Gavin’s team so he’d have someone capable and familiar with the codebase from day one.
He could handle the chaos without drama
Gavin’s main hesitation wasn’t about me—it was about himself. He was knee-deep in the industry with ideas coming from every direction, and he worried he’d be too chaotic for a tech-led process.
“The only hesitation I had working together was, was I going to fry your brain? Were you going to fit well working with me? Because your professionalism and practicality and just your all-round nature, you were able to get from me what you needed to build the product without making me feel as if ‘this guy really doesn’t know anything about tech at all.’”
— Gavin Diamond, Founder, SpareDock
Solution: A 52-page blueprint, a marketplace build, and a developer transition
I ultimately provided Gavin with three things. First, I helped him plan the product blueprint—a 52-page functional spec covering the marketplace for buyers, suppliers, and SpareDock admin. This enabled me to provide him with a fixed price to build his MVP.
Then, once he chose me to actually build the MVP, I hired and managed a dev from contract signing through product launch.
Finally, I transitioned the dev to his team so Gavin could continue building independently.
1. I led a fixed-scope and fixed-cost blueprinting session
During the blueprinting session, I worked with Gavin to understand the business needs and translate them into specific features.
By the end of this session, Gavin knew what he needed to build and what “done” would look like. I also provided a fixed cost and estimated timeline.
“I was able to give you my scope and you came back with what exactly we needed to do. We were able to stick to that. If I had a few slight changes and suggestions, there was no big drama to change the scope. It was just a perfect transition for me from we started in January right through to the product launch a few months later.”
— Gavin Diamond, Founder, SpareDock
2. I built the SpareDock marketplace across 6 phases
I staffed the project with a senior developer (and native English speaker) and managed the build across six phases over approximately 5 months. Gavin and I had weekly Zoom sessions to show progress and get feedback to incorporate into the product over the next week.
It was important for both of us to be aligned on a clear scope for the v1, and regular sync and async communication via Zoom and email helped us get and stay aligned. As Gavin’s product became more “real” little scope changes become desirable, and we incorporated many of his requests without drama.
3. I transitioned a developer to Gavin’s team
Jan, the developer, joined the project and I vetted him over several months before being recommended to Gavin.
“You were methodical and making sure that the developer you recommended to join my team was suitable for my business — you didn’t rush it.”
— Gavin Diamond, Founder, SpareDock
Jan’s been working directly with Gavin since I rolled off the project:
“Jan’s been a great find and a great fit. Once you start giving it to customers and let them use it, you get the enhancements. Jan’s been able to do those things and like yourself, he’s able to come back with, ‘Did we think about this? Do we think about that?’”
— Gavin Diamond, Founder, SpareDock
Results: “The product is doing what it should be doing”
We onboarded SpareDock’s first customer shortly after going live. The product is user-friendly for both sides of the market, and Jan is handling enhancements and building new features.
A product that just works
Gavin was very pleased with the result. In his words,
“There’s not really much to do because the product is doing what it should be doing. Jan’s been able to add enhancements very quickly. I was thinking this is going to be super complicated and people using it is going to take a long time. But we really needed a product and from the very start that was user friendly for both sides of the market. And that’s what we got.”
— Gavin Diamond, Founder, SpareDock
He learned about tech along the way
Beyond the product, Gavin picked up knowledge that lets him have informed conversations about technology going forward.
“In addition to a great product I got lots of learning about tech along the way. Just simple things that allow me to have conversations with people around technology. You were able to guide and advise me which was great. And I picked up a lot in our general discussions which you were happy to have with me along the way.”
— Gavin Diamond, Founder, SpareDock
He valued the real commercial thinking
Gavin appreciated that this wasn’t just a case of taking instructions and following them to the letter. The engagement brought real commercial value.
“Absolutely recommend working with you. You lived up to the two recommendations I got. You brought real commercial value to the project. That wasn’t just a case of taking my instruction and following that to the letter. You were able to ask, ‘Maybe have you thought about this? Have you thought about that?’ Those things were evident from we first met and right through the whole process of getting the final product.”
— Gavin Diamond, Founder, SpareDock
When asked if he would recommend working together, Gavin didn’t hesitate:
“Really, really great individual to work with. Commercially sound, sound product and technical sense, you’re a really good all-rounder. Your skill set in tech is amazing. You’re an excellent communicator and very personable guy. Anybody that asks me about working with you in the future to do any projects, I would have absolutely no hesitation in saying that’s the guy for you.”
— Gavin Diamond, Founder, SpareDock
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