Security Architecture & Design

13 - Architecture

Security Architecture
& Design

Build secure systems before problems are introduced. Security architecture makes sure systems, cloud platforms, networks, applications, identity controls and data flows are designed with security built in from the start. RTCS reduces design risk, identifies gaps early and helps implement controls that support business outcomes without unnecessary complexity.

  • Secure architecture and secure-by-design reviews
  • Cloud security architecture across Azure, AWS and Google Cloud
  • Network and segmentation design
  • Identity, access and Zero Trust architecture
  • Application, API and integration security design
  • Data protection and trust boundary design
  • Threat modelling and architecture risk assessments
  • Logging, monitoring and detection architecture
  • Remediation and uplift planning
Discuss This Service
Focus Areas
Cloud - network - identity - application - data - integration - logging - trust boundaries
Frameworks
NIST CSF - ISO 27001 - Essential Eight - CIS Benchmarks - Zero Trust - STRIDE / threat modelling
Engagement Types
Design review - architecture risk assessment - threat model - cloud architecture - roadmap
Outputs
Architecture review - risk-rated findings - design recommendations - threat model - remediation roadmap
Zero Trust NIST CSF ISO 27001 Essential Eight
Design
Secure-by-Design Reviews
ZT
Zero Trust Planning
TM
Threat Modelling
AU
Onshore Delivery
01 / Context

Security is easier to build in than to add later.

Security architecture is the design of technology systems with security, privacy, resilience and risk management in mind - how users access systems, how data moves, how networks are segmented, how cloud services are configured, how applications are protected and how security controls work together. A good architecture reduces both the likelihood and impact of incidents.

02 / Common Design Gaps

Security issues are usually introduced at the design stage.

G1

Systems exposed unnecessarily

G2

Weak identity and access design

G3

Poor network segmentation

G4

Excessive permissions

G5

Sensitive data moving without clear controls

G6

Security logging added too late

G7

Cloud resources deployed without guardrails

G8

Applications relying on weak trust assumptions

G9

Third-party integrations not reviewed

G10

Security controls not aligned to business risk

03 / Secure Design Review

Find design risk before implementation.

RTCS reviews new or existing designs to identify security gaps before deployment. The output is a clear set of risks, design observations and recommended improvements.

Architecture diagrams Data flows Identity & access controls Network paths Cloud services Application components API integrations Third-party connections Logging & monitoring Backup & recovery
04 / Design Domains

The architecture surfaces we design for.

Cloud Architecture

Landing zones, subscription / account structure, network segmentation, identity and access, storage and database security, key and secret management, public exposure controls, logging and policy governance across Azure, AWS and Google Cloud. Pair with Cloud Security.

Identity & Access Design

Role-based access control, privileged access design, Conditional Access, MFA requirements, service-account controls, guest and third-party access, joiner / mover / leaver and access-review requirements. Pair with Identity & Access Management.

Network & Segmentation

Network zones, firewall rules, remote access pathways, secure management access, private connectivity, internet exposure controls, sensitive system isolation and logging / monitoring points.

Application & Integration

Authentication flows, authorisation models, API access controls, session design, data handling, error handling, logging requirements, third-party integrations and threat modelling.

For broader identity-first design principles applied across the program, see Zero Trust Architecture.

05 / Threat Modelling

Find the attack paths in the diagram, not in production.

RTCS performs threat modelling against architecture, data flows and trust boundaries - identifying likely attack paths, security assumptions, and control gaps before code is written or systems are built. Threat models are practical, documented and tied directly to remediation actions.

Trust boundary mapping Data flow analysis STRIDE-aligned threats Authentication assumptions Authorisation paths Sensitive-data handling Third-party trust Detection & logging needs Control gap recommendations
06 / Architecture vs Pentest

Architecture vs Pentest

Security Architecture Review

Assesses design and control decisions before implementation. Identifies risks in the model, the data flows and the assumptions.

Penetration Testing

Validates exploitable weaknesses in a deployed system or application. See Penetration Testing & Offensive Security. The two support each other - architecture catches design issues, testing catches implementation issues.

Understand to Support

A practical, staged engagement that produces architecture decisions you can defend, evidence and implement.

01
Understand

Review business requirements, systems, risks, constraints and planned changes.

02
Review

Assess architecture, data flows, access paths, trust boundaries and control design.

03
Identify Gaps

Identify design risks, missing controls and areas where security can be improved.

04
Recommend

Provide practical design recommendations that align to business needs and technical constraints.

05
Support

Where required, support implementation planning, remediation and architecture documentation.

07 / Who It's For & What You Receive

Who It's For & What You Receive

Who This Service Is For

  • Designing a new system or platform
  • Moving services to the cloud
  • Need secure architecture review before implementation
  • Need to reduce design risk
  • Need better identity or network architecture
  • Need to review application or API design
  • Need to improve segmentation or access controls
  • Need security input for a major IT project
  • Want practical design advice without complexity

Typical Deliverables

  • Security architecture review
  • Secure design recommendations
  • Architecture risk assessment
  • Threat model
  • Security control mapping
  • Cloud architecture findings
  • Network segmentation recommendations
  • Identity and access design review
  • Data flow and trust boundary review
  • Risk-rated findings
  • Remediation roadmap
  • Executive summary
08 / Related Services

Where architecture connects to the rest of the program.

Zero Trust Architecture

Identity-first design principles applied across users, devices, networks and applications.

Cloud Security

Configuration, exposure and identity assurance for the cloud environments your design specifies.

Azure Security Posture & CIS Benchmark

CIS-aligned configuration review for the Azure landing zones built from the design.

Identity & Access Management

Entra ID, AD and privileged-access controls behind the identity design.

Secure Cloud & Data Engineering

Secure build and data-platform implementation aligned to the architecture.

Security Integration & Engineering

Engineering and integration of the security controls the architecture relies on.

Penetration Testing

Independent validation that the implemented design behaves the way it's supposed to.

Source Code Review

White-box code review that complements architecture-level threat modelling.

Security is easier to build in than add later. Talk to us about security architecture review, secure design advice, cloud architecture, network segmentation, identity design or application security architecture.

Common Questions

What is security architecture?

Security architecture is the design of systems, networks, cloud platforms, applications and controls so they are secure, resilient and aligned to risk.

When should we involve security architecture?

Security architecture should be considered early in a project, before systems are built or deployed. It is usually cheaper and easier to fix design issues before implementation.

Can you review an existing design?

Yes. RTCS can review existing architecture diagrams, data flows, cloud environments, network designs, applications and integrations.

Can you help with cloud architecture?

Yes. RTCS can review or support secure cloud architecture across Azure, AWS and Google Cloud.

Do you provide threat modelling?

Yes. RTCS can perform threat modelling to identify likely attack paths, trust boundaries, security assumptions and control gaps.

Can you work with project teams?

Yes. RTCS can work with internal IT teams, developers, architects, project managers, vendors and managed service providers.

Is this the same as penetration testing?

No. Security architecture reviews assess design and control decisions. Penetration testing validates exploitable weaknesses in a deployed system or application. Both can support each other.

Available across Australia.

RTCS provides independent cyber security support for Australian organisations designing new systems, modernising platforms or reviewing existing architecture. See cyber security services across Australia for location-specific context.