Why structural flaws cost more than bugs
When an engineer makes a mistake in a single line of code, you get a bug. You can patch a bug in an hour. When an engineering team makes a mistake in their system design, you get a structural flaw. You cannot patch a structural flaw. To fix a bad trust boundary, you have to tear down the entire authentication service, migrate the database, rewrite the integration layers, and force all your mobile users to log in again.
In fintech, these structural flaws are what lead to catastrophic data breaches. If your microservices trust each other implicitly, a compromise of your low-security marketing blog allows an attacker to directly query your core banking ledger. If your architecture assumes that internal networks are inherently safe, you are operating on a model that was obsolete a decade ago.
We perform brutal, manual secure architecture reviews. We sit with your lead engineers, we analyze your data flow diagrams, and we systematically break the trust assumptions that your platform relies on. We find the design flaws before you write the code, saving your team hundreds of hours in costly remediation.
Do not wait until production to discover your architecture is fundamentally flawed.
Book an Architecture ReviewWhat we review
We examine how your system is designed, not just how it behaves under attack. The goal is to identify architectural patterns that introduce systemic risk - issues that can't be fixed with a code patch because they're baked into the structure.
Trust boundaries
Where do different trust levels meet? We map every boundary and identify where assumptions are too permissive between your backend, frontend, admin dashboards, and third-party webhooks.
Secret management
How do API keys, database credentials, and encryption keys travel through your system? In a secrets manager, environment variables on developer laptops, or hardcoded in a config committed 18 months ago?
Integration patterns
Every external integration (payment processors, KYC providers, banking APIs) introduces a trust assumption. We review how your system validates external data, handles failures, and protects against integration-layer attacks.
Internal surface exposure
Admin dashboards, support tools, internal APIs, and debug interfaces. These often have weaker access controls than customer-facing surfaces but more powerful capabilities.
Data flow and storage
How does BVN, PAN, and transaction data flow through your system? Where is it stored, cached, logged, or serialized? We trace data paths and identify points where PII could leak.
Service-to-service auth
In microservices, internal services often trust each other implicitly. We review how services authenticate to each other, how network boundaries are enforced, and what happens if one service is compromised.
Threat modeling the fintech environment
Our architecture reviews are driven by rigorous threat modeling. We do not just look at your AWS diagrams and nod our heads. We apply frameworks like STRIDE to your specific payment flows.
1. The webhook vulnerability model
Fintech architectures heavily rely on asynchronous webhooks. When Paystack or Flutterwave processes a payment, they send a webhook to your API. We review your architecture to see what happens when an attacker spoofs that webhook. Does your architecture mandate cryptographic signature verification on every inbound request? Or do you just trust the payload because it looks correct?
2. Internal dashboard risk
The highest-risk component in any Nigerian fintech is the internal customer support dashboard. Support agents have immense power: they can freeze accounts, initiate chargebacks, and view KYC documents. We review the architecture of these internal tools. We ensure they are placed on segmented networks (like a zero-trust VPN) and that they do not share direct database connections with the customer-facing API.
3. Cloud infrastructure and IAM
We review your AWS, GCP, or Azure environments. A common architectural failure is granting wildcard (`*`) IAM permissions to CI/CD runners. If an attacker breaches your GitHub repository, they gain full administrative control over your production AWS environment. We map out these permission models and enforce the principle of least privilege at the architectural layer.
Over-trusted internal dashboard
The customer support dashboard shared the same database connection string as the production API - with full read-write permissions on all tables. Any support agent could theoretically modify any customer's balance or KYC status. The application-level permissions were fine; the infrastructure-level trust boundary was nonexistent.
A bad trust boundary can compromise your entire system. Let us map your risks.
Request an Architecture ReviewWhat to prepare for the review
Send a current architecture diagram, data-flow diagram, user and service roles, deployment model, key integrations, and the controls used for identity, secrets, logging, and approvals. Mark the paths that move money, change balances, expose personal data, or grant privileged access.
The review covers design and control placement. It does not prove that the deployed code enforces the design. Use penetration testing after implementation to test the live controls. Use a source code review when the main question sits inside a specific code path.
Decisions the review must settle
An architecture review is not successful unless it forces your engineering team to make concrete, defensive decisions. At the end of our engagement, we will provide an executive report and an engineering deep-dive that explicitly settles these questions:
- Which system owns identity, authorization, transaction state, and audit evidence.
- Where untrusted data enters and which service validates it.
- Which actions require a second approval or a separate role.
- How secrets rotate and how the team revokes a compromised key.
- Which logs prove who changed money, access, or customer data.
If your architecture cannot definitively answer these questions, you are exposed. We provide the exact architectural patterns required to fix the gaps, including infrastructure-as-code templates and proven design strategies used by global financial institutions.
Related services and resources
Architecture reviews pair naturally with penetration testing (which validates the running implementation) and vulnerability assessments (which map tactical weaknesses). For API-specific authorization testing, see our dedicated service. If you're a startup, see our startup engagement model.
Frequently asked questions
How is an architecture review different from a penetration test?
A pentest exploits existing vulnerabilities in a running application. An architecture review examines the design decisions and trust boundaries that create or prevent vulnerabilities. A pentest asks 'can I break in?' An architecture review asks 'why is this wall made of glass?'
Do you need access to our source code?
Architecture diagrams, data flow docs, and infrastructure topology are essential. Source code access is beneficial but not always required. We'll discuss optimal access during scoping.
When should we get an architecture review?
Before a major migration, before adding a new payment integration, before onboarding enterprise customers, or after a significant security incident. Architecture reviews are highest-value when they can influence design decisions before code is written.
Can you review microservices architectures?
Yes. Microservices introduce specific challenges around service-to-service authentication, secret distribution, network segmentation, and shared data stores. We review inter-service trust assumptions, often the weakest link in modern fintech platforms.