SaaS & Scale-Ups
Multi-tenant architecture that survives growth. Billing infrastructure that doesn't leak revenue. Technical foundations that survive Series B due diligence. Senior engineers who've built SaaS products that actually scaled.
Technical audits from £3,000 · Architecture projects from £12,000 · Fixed-price scoping available
Series A/B
Technical readiness assessment included
10x
Growth capacity built into every architecture
£600
Per day — transparent, no surprises
4wk
Typical time to production-ready multi-tenancy
Sound familiar?
🏗️
You built fast, you shipped fast, and now every new customer makes the system slower. Your single-tenant setup can't support the multi-tenancy your enterprise prospects demand. Row-level security is missing. Tenant isolation is theoretical. The architecture that got you to Series A won't get you to Series B.
💳
Stripe is powerful. It's also genuinely complex when you need usage-based pricing, seat-based tiers, annual/monthly switching, proration, trials, and enterprise custom contracts. Most SaaS billing implementations are held together with webhooks and prayer.
🔍
What's your infrastructure cost per customer? How does your system handle 10x growth? What does your security posture look like? Technical due diligence at Series B isn't about features — it's about architecture quality, deployment practices, and whether your codebase will survive the next 18 months.
⏱️
The codebase that two engineers shipped in six months is now a 400,000-line monolith that takes three sprints to change a feature flag. New engineers spend two weeks getting the dev environment running. Every deployment involves a 90-minute QA cycle. This is solvable — but it requires engineering discipline, not more features.
How we help
01
Database-level tenant isolation using PostgreSQL row-level security or schema-per-tenant depending on your scale profile. We design and implement the tenancy model that balances security, performance, and operational complexity — then migrate your existing customers across without downtime.
02
Stripe Billing, usage metering, seat-based pricing, annual/monthly switching, proration logic, and dunning workflows. We've built billing infrastructure for SaaS products at every stage from pre-revenue to £10M ARR. The edge cases in billing are where the money leaks — we close them.
03
Pre-raise technical audits that give investors the answers they want before they ask. Architecture review, security posture assessment, infrastructure cost modelling, codebase quality scoring, and a prioritised remediation roadmap. We've seen what Series B investors scrutinise — we prepare you for it.
04
Reduce your deployment cycle from days to minutes. Feature flags, trunk-based development, ephemeral environments for PRs, automated testing pipelines, and the infrastructure tooling that lets your team ship with confidence. DORA metrics that impress investors and actually mean something.
Why Vanguard
London SaaS agencies charge £700-1,100/day. Cheap offshore shops charge £200-450/day and require you to manage them. Vanguard sits in the middle at £600/day — senior-only, UK-based, with the enterprise engineering pedigree (McLaren Racing, Vodafone-scale systems) that your Series B investors will recognise.
London Agencies
£700-1,100/day · Account managers in the loop
Vanguard
£600/day · Senior only · AI-accelerated delivery
Offshore Teams
£200-450/day · You manage them · Quality variance
Pricing
Technical audits from £3,000. Fixed-price scoping available. Know your investment before the contract is signed.
Ready to start?
Tell us where your architecture is breaking, what your investor timeline looks like, and what you need to fix before the next raise. We'll come back with a concrete plan.
Typical response within 24 hours · No sales pressure