marketplace development

Marketplace development for B2B & multi-vendor platforms.

We've built 50+ marketplaces over 15 years, with senior developers directing AI agents through every release.

2005 Est. 2005
60+ five-star Google reviews
350+ Projects delivered
7 Marketplaces operated
case studies

Marketplace platforms built to transact

Bid4Wine · Auction marketplace

Zero-latency live bidding with automated payouts

Bid4Wine
Bid4Wine marketplace
RevXtra · Automotive marketplace

Car buying where approved dealers do the competing

RevXtra

“We’ve been working with James and the team at Code23 on the development of RevXtra and the experience so far has been excellent.”

Billy Davis Co-founder, RevXtra
RevXtra marketplace

Verified client review

RevXtra / Project evidence

In their own words.

“We’ve been working with James and the team at Code23 on the development of RevXtra and the experience so far has been excellent.

From the outset, they’ve taken the time to really understand what we’re trying to build rather than simply doing what we ask. They’ve challenged ideas when needed, offered solutions and helped turn what started as a concept into a genuine product.

Communication has been great throughout and it genuinely feels like they’re invested in making RevXtra a success, rather than us just being another client.

I’d have no hesitation recommending James and the Code23 team.”

Full review / 4 paragraphs
Costhetix · Service marketplace

A secure two-sided marketplace built around practitioner trust

Costhetix

“Working with Code23 to build Costhetix has genuinely been one of the best decisions I've made as a founder… They're knowledgeable, approachable, responsive and exceptionally good at what they do. I wouldn't hesitate to recommend them to any founder or business looking for a development partner they can genuinely trust.”

Nicola Kay portrait
Nicola Kay Founder, Costhetix
Costhetix marketplace

Verified client review

Costhetix / Project evidence

In their own words.

“Working with Code23 to build Costhetix has genuinely been one of the best decisions I've made as a founder… They're knowledgeable, approachable, responsive and exceptionally good at what they do. I wouldn't hesitate to recommend them to any founder or business looking for a development partner they can genuinely trust.

Full review / 1 paragraph
Virtualstock · Enterprise marketplace

Europe's largest dropshipping platform redesigned around its users

Virtualstock

“The platform UI they delivered is completely transformed. The UX is intuitive, the dashboard now showcases the operational metrics that matter, and the modern UI gives our platform the enterprise feel our clients wanted.”

Ed Bradley portrait
Ed Bradley Founder and CEO, Virtualstock
Virtualstock marketplace

Verified client review

Virtualstock / Project evidence

In their own words.

“The platform UI they delivered is completely transformed. The UX is intuitive, the dashboard now showcases the operational metrics that matter, and the modern UI gives our platform the enterprise feel our clients wanted.

Full review / 1 paragraph
CosthetixKinurtureBigSleepWorkVansSponsorfy Away Pubs Jollee
why marketplaces fail

Liquidity, payments, inexperience

We still operate seven marketplaces with our own money on the line - after 50+ builds across fifteen years. Liquidity, Stripe Connect payouts and take-rate maths sink marketplaces more often than bad code, so Map starts there.

[ 01 ]

No liquidity, no marketplace

Empty marketplaces stay empty. Buyers won't come without supply, suppliers won't list without buyers.

OS teaserSupply + demand outreach running from launch, not month six
[ 02 ]

Payments complexity kills momentum

Split payouts, vendor KYC, refunds and disputes across dozens of sellers. Get it wrong and trust evaporates.

Stripe ConnectSplit payouts running in production on our platforms
[ 03 ]

Agencies that have never run one

Most teams hand over the keys and leave. They've never had to find supply, price a take rate or fight churn themselves.

50+ builtSeven operated today with our own money on the line
marketplace business os

A marketplace that runs itself is the goal

Every Code23 marketplace can plug into our agentic operating system: agents that work your marketplace around the clock, directed by you.

SAMPLE DATA
Marketplace OS · Live queue

Supply and demand outreach, running 24/7

Agents work both sides of the market from day one - prospect queues, sequenced sends, reply triage - while you set the brief and approve the tone.

Live queue
outreach console
Sent 128 Replied 34
agent.outreach · sequencing supply batch 04
Northfield Supply Sent
Harbor Procurement Replied
Cedar Lane Goods Queued
Atlas Facilities Sent
Vendor 19 · London Typing…
capabilities

Marketplace surfaces we engineer

Custom marketplace websites

Listings, search, messaging, reviews, admin and the full transaction loop - engineered from the data model out, not bolted onto a shop theme.

B2B marketplace platforms

Trade accounts, quote flows, bulk ordering, credit terms and compliance for buyers who purchase on behalf of a business.

Multi-vendor commerce

Seller KYC, catalogue tools, commission rules and operator queues - the supply-side surface that decides whether liquidity ever forms.

Service marketplaces

Booking, availability, vetting and two-sided reviews for platforms that sell people's time. We operate several of these ourselves.

Payments & Stripe Connect

Split payments, vendor onboarding, KYC, automated payouts, refunds and disputes - Stripe Connect as the default money path.

C2C & peer marketplaces

Peer listings, trust and safety, disputes and take-rate economics so casual sellers and buyers finish clean transactions.

out of the box

The operating surfaces a marketplace needs

Vendor onboarding, payments, bookings, messaging and moderation ship in the core build - the same stack behind the seven platforms we still run.

SAMPLE DATA
Ops dashboard

Dashboard

GMV, liquidity and cohort views your operators actually open.

7d
GMV £184k
Liquidity 62%
Take £23k
GMV · 12 weeks +18% WoW
Top vendors 7d GMV
Northfield Supply
£42.8k
Vendor 02
£31.4k
Harbor & Co.
£28.1k
Vendor 04
£19.6k
Cedar Lane Goods
£14.2k

"We've recently completed Phase 1 of a bespoke business valuation tool with James at Code23, and I've been extremely impressed. He took the time to understand both the commercial and technical requirements, communicated clearly throughout, and delivered a well-thought-out system."

Jason Atkins Director, Lansley Commercial
Delivery model

Operators direct. Agents multiply.

Senior developers steer marketplace agents across outreach, listings, build and QA - operator judgement at machine throughput.

Senior lead Directs · Decides · Signs off

Supply outreach agent

Fills both sides of the market

Listing agent

Enriches inventory and content

Build agent

Ships platform features in parallel

QA agent

Hammers payment flows before buyers do

Every consequential decision and production release is signed off by a human.

How we work

From liquidity model to live payouts.

Commercial truth first, then architecture, then an agent-accelerated build with operators still in the room.

Step 1

01 - Map

Supply, demand, take rate and the transaction loop land first - commercial truth ahead of architecture diagrams.

Scanning market
51.4551°N / 0.9787°W 6 signals

Step 2

02 - Blueprint

Listings, transactions, payouts and UI prototypes locked into a fixed-scope plan your operators can defend.

Spec 02 / grid 8px
Scope locked 1390px

Step 3

03 - Build

Senior developers direct AI agents across marketplace surfaces in parallel, with review on every merge.

Sprint 03
Working software Week 2

Step 4

04 - Harden

Payout edge cases, refunds and disputes get probed at machine depth before money moves in production.

Audit: release 2.4
0 critical 6 checks passed

Step 5

05 - Launch

Payments live, monitoring on, and a cold-start plan so supply is seeded ahead of buyers.

Deploy: production Live
Uptime 100.00% v1.0.0

Step 6

06 - Evolve

Liquidity metrics, take-rate tuning and feature scaling - the same loop we run on the seven we operate.

Release cadence
v1.0 v1.4 v2.0
Shipping weekly +340%
the offer

Free 30-minute marketplace scoping call

Walk liquidity, Stripe Connect and Marketplace OS with a senior specialist who has launched and operated marketplaces - viability first, estimate second.

You leave with
01 A liquidity plan for your first 90 days
02 A payments architecture sketch on Stripe Connect
03 A build outline with timeline and scope boundary
04 A straight answer on whether it's viable
why code23

What operators notice first

[ 01 ]

50+ marketplaces, seven operated

Fifteen years of marketplace development. Costhetix, Kinurture, BigSleep, WorkVans, Sponsorfy, Away Pubs and Jollee still run on our watch - playbooks from operators, not slide decks.

[ 02 ]

5x build speed, senior controlled

Build and ops run under senior specialists with agents on the bulk. Harden gates hold; calendar and burn drop.

[ 03 ]

Payments in production

Stripe Connect split payments, vendor KYC and automated payouts already live on our platforms. We do not invent your money path in theory.

[ 04 ]

Liquidity thinking first

Empty markets stay empty. We map supply, demand and the first 90-day seeding plan before UI expands - then plug into Marketplace Business OS outreach so both sides keep filling.

[ 05 ]

Harden on payment flows

Named Harden step on payouts, refunds, disputes and trust edges. Agents probe at machine depth under operator-grade review.

[ 06 ]

Senior team, direct

You work with the people building the marketplace. No account-manager relay, no offshore handoff. Reading, UK.

verified reviews

On the record, on Google

Real reviews from our Google Business profile.

Google 60+ reviews →

We've recently completed Phase 1 of a bespoke business valuation tool with James at Code23, and I've been extremely impressed. He has taken the time to understand both the commercial and technical requirements, communicated clearly throughout, and delivered a well-thought-out system with a high level of flexibility. The admin dashboard, in particular, gives us full control over the scoring and valuation logic, which was a key requirement. I'm looking forward to working with James on Phase 2 and would have no hesitation in recommending him to anyone looking for bespoke software development – Jason Atkins, Director, Lansley Commercial

Jason Atkins portrait
Jason Atkins Lansley Commercial

We couldn’t be happier with the service from Code23. They were a pleasure to work with—friendly, professional, and really took the time to understand our needs. They met our brief perfectly, delivering a website that looks great and performs exactly as we envisioned, all at excellent value for money. What sets Code23 apart is their aftercare. Knowing they are on hand to monitor and maintain our website means we never have to worry about its performance. Their ongoing support gives us complete peace of mind, and we’d highly recommend them to anyone looking for a reliable and skilled web development team

Dan Isterling portrait
Dan Isterling Premier Community

It has truly been a fantastic experience working with the Code23 team. Every part of the process from the scoping and onboarding down to the design and implementation of our website was handled excellently. The quality of service delivered by the team is globally top standard and I couldn't be more satisfied with the final outcome.

Samuel Elili portrait
Samuel Elili Redwire Group

I have worked with Code23 and their team for over 5 years across 3 different projects ranging from mobile app development to custom WordPress websites. Together the team bring a level of expertise and professionalism I have not seen anywhere else... The results achieved have really helped to grow our business. I highly recommend their services to anyone looking for a custom project to be completed on time and in budget.

Alexander Campbell portrait
Alexander Campbell EnjoyCBD

We worked with Code23 for a complete rebuild of our music related website. Excellent customer service and quality throughout and the build they have now completed is fantastic - exceeded all expectations across the board. Fantastic company with a dynamic and motivated team who are great to work with. Would highly recommend!

Nathan Fullbrook portrait
Nathan Fullbrook Jamma Music

Joe and the team at code23 have done a fantastic job helping us design and build our new website. I feel they really captured the quality of the Draks brand. Would highly recommend.

Louise Sellar portrait
Louise Sellar Draks

blogs

Marketplace thinking

Take rates, supply seeding, Stripe Connect and the operating loops behind multi-vendor platforms.

View all posts
About Code23

Seven on our balance sheet. Fifty-plus built.

We've built 50+ marketplaces over 15 years and still operate seven with our own money. You work with the people who run those platforms: no account-manager relay, and agents that multiply operator throughput.

Meet Code23
Est. 2005 Reading, UK Hands-on senior team
The Code23 team working together in the Reading studio
Fig. 01 - The team, Reading studio 51.4551°N / 0.9787°W
James, founder of Code23
Fig. 02 - James, founder EST. 2005
A product review session at Code23
Fig. 03 - Product review WK 34 / 2026
faq

Marketplace questions, answered

How much does it cost to start an online marketplace?

It depends on the number of sides, payments depth and how custom the MVP is. Blueprint defines the transaction loop and first release, then current pricing is confirmed against that agreed scope.

How long does marketplace development take?

The Blueprint MVP cut sets the timeline, including payments and first supply tools. Multi-vendor and B2B approval flows add time - we say so up front. Agents compress build; integrations and supply seeding usually set the critical path.

How to develop a marketplace?

Start with supply and the transaction loop, then architecture and payments. We run Map, Blueprint, Build, Harden, Launch, Evolve so commercial truth lands before UI expands.

How does a marketplace make money?

Commission on each transaction is the standard model. Listing fees, vendor subscriptions and featured placement sit alongside it. We model the take rate in scoping - that number decides whether the platform is a business.

Can AI agents really run marketplace operations?

Yes, inside a clear remit. Agents already handle outreach, listing enrichment, support triage and QA while seniors set policy and own risk - so you run lean without losing the operating judgement.

Which marketplaces do you operate yourselves?

Seven: Costhetix, Kinurture, BigSleep, WorkVans, Sponsorfy, Away Pubs and Jollee. We built each one and still run them day to day. Across 15 years we've shipped 50+ marketplaces in total.

Do you use Stripe Connect for multi-vendor payouts?

Yes. Stripe Connect is our default: split payments, vendor KYC, automated settlement, refunds and dispute handling, with reconciliation built in.

get started

Got supply, demand and a take-rate thesis?

Bring the model. We'll bring 50+ builds, seven we still operate, and senior developers who ship at 5x speed.