Confidential — Regional Banking SaaS
Architecture Audit for a Banking SaaS Before Series B
- 4 weeks
- Audit duration
- Investor-ready report + roadmap
- Output
- Closed at target
- Series B
- Quarterly refresh retainer
- Follow-up
Project details
The Challenge
Our client is a regional digital-banking SaaS platform powering branchless banking, mobile wallets, and a card-issuing programme for a portfolio of partner banks and microfinance institutions. By the time they engaged us, they were two weeks into a Series B fundraise and facing serious technical-due-diligence questions from a lead investor's appointed CTO advisor. The internal team was confident the platform worked — but couldn't credibly answer the deeper questions on their own.
Where was technical debt accumulating fastest? What was the realistic blast radius of a partner-bank outage? Could the platform scale several-fold without an architectural rewrite? Was the security posture adequate for the AML/CFT obligations that came with a banking-licensed customer base? Investors wanted a clear-eyed, independent answer, on a four-week clock.
Our Approach
The engagement was scoped tightly: a four-week independent architecture audit producing a single deliverable — a long-form report ready to share with the lead investor's technical committee, plus an executive summary the CEO could walk a board through. No prescriptive remediation; just clarity, prioritisation, and a credible path forward.
Our process across the four weeks:
- Week 1 — Discovery. Structured interviews with engineering, product, ops, security, and partner-onboarding leads. Full read-only access to GitHub, the cloud account, the observability stack, the SCA tooling, and the team's incident-management system.
- Week 2 — Deep dive. Architecture reconstruction from first principles. We rebuilt the system context diagram, the deployment topology, the data-flow diagram for every regulated data class, and the trust boundaries. Several of these had never existed in writing.
- Week 3 — Stress points. Targeted analysis of the highest-risk areas: partner-bank integration patterns, AML transaction monitoring, the legacy ledger, the card-tokenisation service, the IAM platform, the cost trajectory, and the disaster-recovery posture.
- Week 4 — Synthesis. Findings document, prioritised remediation roadmap, presentation deck for investors, exit interview with the CTO.
The output landed as a prioritised findings list, scored on a two-axis severity-by-effort matrix. A handful were "critical" — including a partner-bank webhook integration with no idempotency guarantees that was a latent double-credit incident waiting to happen, and a transaction-monitoring rule engine that was meaningfully behind on FATF typology updates. A larger group were "high-impact, low-effort" — exactly the category Series B investors wanted to see, because they signal a healthy team that simply needed prioritisation time.
On the upside, we identified a meaningful annualised infrastructure-savings opportunity achievable without product impact — most of it in database right-sizing, object-storage lifecycle work, and removing services that had no live traffic but were still costing money on idle compute and load balancers. We deliberately under-promised on the savings number to keep it credible in the investor conversation.
The Outcome
The audit report was delivered on schedule. The lead investor's technical committee accepted the findings without dispute, the Series B closed at the targeted valuation, and the client's CTO has cited the report internally as the most useful document the engineering org has produced in years. The high-impact, low-effort findings became the team's roadmap for the following quarter; most were closed inside that window.
The longer-term win is institutional. The system-context, deployment-topology, and data-flow diagrams we produced are now living documents — the engineering team treats them as canonical, and they're in use for partner-bank onboarding and for the regulator's annual review. We've been retained on a periodic cadence to refresh the audit lightweight.
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