What I build: SaaS platforms and web applications
Most web projects I’m asked about are business software rather than brochure sites: a product customers log in to, pay for and rely on every day. I build the whole thing, from the database to the screens, so there is one person accountable for how the parts fit together.
The same approach works for a first version and for a platform that already has customers. For an MVP, the job is to ship the smallest product that proves the idea without building something you will have to throw away. For a growing platform, it is to add features, integrations and scale without slowing the team down.
- Multi-tenant SaaS products, where each customer’s data and users are kept separate by design
- Customer portals, dashboards and internal tools that replace spreadsheets and manual work
- Two-sided platforms and marketplaces, with separate experiences for each side
- Subscription billing and payments with Stripe, plus sign-in, roles and permissions
- Integrations with the systems your customers already use, through REST APIs and webhooks
- Rebuilds and rescues of existing platforms that have become slow, fragile or hard to change
From requirements to handover: how a build runs
Buyers usually ask the same question first: what happens between the first call and a working product? Every build follows the same lifecycle, and each stage ends with something you can see and check.
You get weekly demos throughout, so progress is visible in the product rather than in status reports, and decisions that affect scope or cost come to you in writing before they are made.
- Requirements and scoping: users, roles, core workflows, integrations and what “done” means for the first release
- Architecture: data model, tenancy, APIs, hosting and security, written down and agreed before code is written
- Development: the product built in iterations, with tests and code review, and working software at each milestone
- Deployment: CI/CD, staging and production environments, monitoring and a staged launch
- Handover: documentation, runbooks and a session with your team, so the platform does not depend on me
Next.js and FastAPI development, and the rest of the stack
I use a small set of proven tools, chosen because any competent engineer can pick them up after me. My default for a new SaaS product is a Next.js and TypeScript front end with a Python FastAPI back end, because typed contracts on both sides make the system easier to change safely. Where a product needs a rich admin, mature libraries or a large data model, Django is often the better back end, and Node.js fits real-time and event-driven work.
If you already have a stack, I work in it. The choice should follow your team, your hiring plans and the product, not my preferences.
- Front end: React, Next.js, TypeScript and Tailwind CSS
- Back end: Python (FastAPI, Django) and Node.js
- APIs: REST, GraphQL and microservices, where splitting services earns its extra complexity
- Data: PostgreSQL, MongoDB, MySQL and Redis, with Celery for background jobs
- Payments and identity: Stripe billing, sign-in, MFA and role-based access control
- Delivery: Docker, CI/CD with GitHub Actions, and deployment to AWS or Cloudflare
Security built in from day one
Most agencies build the product and leave security to a penetration test just before launch, when every finding is expensive to fix. I build and red-team systems, so I design against the attacks I test for elsewhere: broken access control between customers, leaked secrets, unsafe file uploads and APIs that trust whatever they are sent.
That background includes an MSc in Cyber Security and Forensic Information Technology from the University of Portsmouth, implementing encryption, MFA and RBAC and working on SOC 2 and ISO 27001 for a real-time industrial safety platform at Bodytrak, and being named Cybersecurity Engineer of the Year 2026 in the Corporate LiveWire Innovation & Excellence Awards. If enterprise customers will ask for SOC 2 or ISO 27001 later, the controls are easier to prove because they were built in from the start.
- Tenant isolation and role-based access checked on every request, not only hidden in the interface
- Encryption in transit and at rest, and secrets kept out of code
- MFA and single sign-on where the product or its customers need them
- Audit logging of who did what, from the first release
- Dependency and secrets scanning in CI/CD, with protected branches
- A security review of the finished build before launch
Web application development for startups
An MVP should be small, but it should not be disposable. The decisions that are hardest to change later, such as the data model, how customers are separated from each other and how sign-in and payments work, are cheap to get right at the start and expensive to retrofit. I spend the architecture time there and keep everything else as simple as possible.
You also get the senior judgement that early teams often lack: what to build now, what to buy rather than build, and what can wait until customers ask for it. If you later need ongoing engineering leadership while you hire, that can continue as a fractional Head of Engineering engagement.
Case studies: Kaivo, Evntt, CityOS and Carbon Giant
Kaivo is a multi-service platform for marketing agencies to manage client ad accounts, campaigns and performance across Google, Meta, TikTok, LinkedIn, Microsoft, Reddit, Spotify and Shopify. I designed and built it end to end with a Next.js front end and FastAPI microservices, deployed on Cloudflare and AWS, keeping each ad platform integration in its own service so a change on one platform does not take down the rest.
Evntt is a two-sided events SaaS for hosts and attendees: branded host profiles with live-preview customisation, ticketing, Stripe billing, analytics, merchandise and QR promotion. I designed and built it on React, TypeScript, Node.js and PostgreSQL, hosted on AWS.
CityOS connects to venues’ POS and reservation systems, enriches first-party guest data and runs guest recovery and retention campaigns, with a real-time dashboard showing which guests returned and the revenue impact. Carbon Giant turns invoices and Xero, QuickBooks and Sage data into Scope 1–3 emissions calculations and audit-ready reports for UK SMEs on Next.js, FastAPI and PostgreSQL. Hallward, a Primavera P6 analytics platform built on React, Django REST Framework, Celery and AWS Cognito, shows the same pattern for heavy file processing: the slow work runs in background jobs so the product stays responsive.
What you get
- A written scope and architecture covering users, data model, tenancy, integrations and hosting
- A production web application or SaaS platform, deployed in your own cloud account
- Payments, sign-in, roles and the third-party integrations agreed in the scope
- Automated tests and a CI/CD pipeline that deploys to staging and production
- Security controls built in, and a security review before launch
- Weekly demos throughout the build
- Documentation, runbooks and a handover session for your team
How it works
Step 01 · Before the build
Discovery and scope
NDA first, then working sessions on your users, workflows, integrations and what the first release must do. You get a written scope, milestones and a fixed or capped price before any work starts.
Step 02 · Typically the first 1–2 weeks
Architecture and design
The data model, tenancy, APIs, security and hosting written down and agreed, plus the key screens, so expensive decisions are made deliberately and early.
Step 03 · Agreed milestones
Build in iterations
Hands-on development with weekly demos on a staging environment. Each milestone ends with working software you can click through, not a progress report.
Step 04 · Before go-live
Harden and launch
A security review, load and payment testing, monitoring and alerts, then a staged launch to real users.
Step 05 · At launch
Hand over
Documentation, runbooks and a handover session, so your team can run, change and extend the platform without me.
Proof
“Steady progress, predictable delivery, and code that’s easy to review and integrate.”
Sean Metcalf
Founder, getKaivo
“He was able to deliver many parts of our system, communicate efficiently, and was fun to work with throughout the engagement.”
Chen Atlas
CTO & Founder, Optery
“His knowledge of security, cryptography, and database design was of crucial importance to our product’s successful development.”
Rod Ast
CEO & Founder, 911 Vault
Price
From £12,000. For a scoped build from architecture to launch, with a fixed or capped price agreed in writing. Every engagement starts with a free 1-hour intro call, and you get a written scope with a fixed or capped price before any work starts.
FAQ
How much does it cost to build a SaaS platform in the UK?
My Build Projects start from £12,000 for a scoped first release, from architecture to launch. The price depends on the number of user roles, the integrations, payments and how much security and compliance work the product needs. You get a fixed or capped price in writing before work starts, and hosting and third-party services are billed to your own accounts.
How long does it take to build a web application or MVP?
It depends on scope, so I don’t quote a timeline before discovery. The main drivers are the number of user roles and core workflows, the third-party integrations, payments, whether designs already exist and whether we are starting fresh or working in an existing codebase. The written scope sets out milestones you can plan around.
Do you sign an NDA, and who owns the code?
Yes, I sign an NDA before discovery. You own the code and the intellectual property once the work is paid for, and it is built in your own repositories and cloud accounts, so nothing is locked to me.
Can you take over or rebuild an existing platform?
Yes. I start by reviewing the code, data model, hosting and security, then tell you plainly what is worth keeping and what is worth rebuilding. Most platforms are better improved in stages than rewritten from scratch, and the scope says which.
Should we use Next.js and FastAPI, Django or Node.js?
For a new SaaS product I usually recommend Next.js and TypeScript with FastAPI, or Django where a rich admin and a large data model matter. Node.js suits real-time and event-driven work. If your team already knows a stack, staying with it is often the better choice, and I build in it.
Will you work with our in-house team?
Yes. I can build the platform alone, lead a small team or pair with your engineers. Either way, code is reviewed, documented and handed over so your team can carry it on.