Security Engineering

Security-by-Design

At DevSimplex, security is not a phase at the end of development — it is woven into every decision from requirements through to production operations. This document outlines our security-by-design framework.

OWASP Top 10ISO 27001GDPRSOC 2NIST CSF

Core Security Principles

Six fundamental principles that guide every architecture, design, and implementation decision.

Least Privilege

Every component, service, and user account receives only the minimum access rights required to perform its function. Access is revoked immediately when no longer needed.

  • Role-based access control (RBAC)
  • Zero-trust network architecture
  • Automated access reviews
  • Privileged access management (PAM)

Defence in Depth

We layer multiple security controls so that if one fails, others remain in place. No single point of failure can compromise an entire system.

  • WAF + application-layer validation
  • Network segmentation
  • Encryption at rest and in transit
  • Multi-factor authentication everywhere

Fail Securely

Systems are designed to default to a secure state when an error occurs. Error messages never expose sensitive information to end users.

  • Generic error responses in production
  • Structured logging to secure sinks
  • Circuit breakers with secure defaults
  • Graceful degradation strategies

Secure by Default

All configurations ship in the most secure state. Features that reduce security require explicit opt-in, not opt-out.

  • HTTPS enforced everywhere
  • Security headers on all responses
  • Secrets management via Vault/SSM
  • Dependencies pinned and audited

Open Design

Security does not rely on obscurity. Our designs withstand scrutiny — algorithms, architectures, and controls are sound even when known to an attacker.

  • Peer-reviewed architectures
  • Third-party penetration testing
  • Threat modelling per feature
  • Open-source dependency audits

Minimise Attack Surface

Every endpoint, dependency, and feature is a potential vector. We reduce surface area by removing what is not needed and hardening what remains.

  • Dependency minimisation
  • API input validation & sanitisation
  • Unused ports and services disabled
  • Regular SAST/DAST scanning

Security Across the SDLC

Security activities integrated at every phase of our software development lifecycle.

1

Requirements

Security user storiesCompliance mapping (GDPR, HIPAA, PCI)Risk classificationData flow identification
2

Design

Threat modelling (STRIDE)Architecture security reviewAuthentication & authorisation designEncryption strategy
3

Development

Secure coding guidelinesSAST (static analysis) in CIDependency vulnerability scanningCode review security checklist
4

Testing

DAST (dynamic analysis)Penetration testingSecurity regression testsSecrets scanning in git history
5

Deployment

Infrastructure hardeningSecurity headers validationSecrets management auditAccess control review
6

Operations

Continuous monitoring & alertingIncident response planRegular security reviewsPatch management policy

Build Secure Software with DevSimplex

Security-by-design is included in every engagement. Let's discuss how we can protect your product from day one.

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