Secure Software Development Life Cycle
Security built into every stage of software development
SSDLC builds security requirements, testing and risk control into the software development lifecycle. We detect vulnerabilities where fixing them costs least — in the design and the pull request.
# pipeline — security stage sast: block critical sca: SBOM + licences secrets: scan every commit dast: test environment release: requires [security, review]
Sample configuration — illustrative data
Why SSDLC
Security stops being an audit at the end of the project
The later a vulnerability is found, the more expensive the fix and the greater the business risk.
- Without SSDLCVulnerabilities detected after deployment or by customersWith SSDLCVulnerabilities detected in the pull request and pipeline
- Without SSDLCSecurity as a one-off audit before launchWith SSDLCSecurity requirements from the first sprint
- Without SSDLCUnclear who is responsible for risk acceptanceWith SSDLCDefined roles, gates and risk owners
- Without SSDLCCompliance hard to demonstrateWith SSDLCArtefacts — threat model, reports, SBOM — as evidence
SSDLC stages
Seven stages, one closed loop
Select a stage to see what we do, which artefacts are produced and what it means for your team.
Stage 01 of 07
Security requirements
Before the first line of code is written, we establish what data the system processes, which regulations apply and how we will know it is secure enough.
What we do
- data and role classification
- regulatory requirements (e.g. NIS2, GDPR)
- security acceptance criteria in the backlog
Deliverables
- requirements catalogue
- data classification
Outcome: security is measurable from the first sprint.
Stage 02 of 07
Threat modelling
We analyse data flows and trust boundaries, identify threats (e.g. using STRIDE) and decide which risks to address first.
What we do
- data flow diagrams
- identification of threats and attack scenarios
- priorities and countermeasures
Deliverables
- threat model
- risk register
Outcome: the team knows what to protect and against what.
Stage 03 of 07
Secure architecture
We design the architecture on the principle of least privilege: identity, segmentation, encryption and secrets management are design decisions, not fixes.
What we do
- principle of least privilege
- encryption and secrets management
- reference patterns for the team
Deliverables
- architectural decisions
- reference patterns
Outcome: fewer vulnerability classes at the design stage.
Stage 04 of 07
Secure development
We support the team with secure coding standards, checklist-based code review and control of third-party libraries.
What we do
- secure coding standards
- code review with a security checklist
- dependency and licence control
Deliverables
- review checklist
- SBOM
Outcome: bugs caught in the pull request, not in production.
Stage 05 of 07
Security testing
We automate tests in the pipeline and complement them with manual testing where risk is highest — including APIs and IoT devices.
What we do
- SAST, SCA and secret scanning in CI
- DAST in the test environment
- penetration tests before a key release
Deliverables
- test reports
- remediation backlog
Outcome: findings with a priority and an owner.
Stage 06 of 07
Deployment and hardening
Each release passes security gates, and environments have a hardened baseline configuration and a controlled change process.
What we do
- security gates in CI/CD
- hardened environment configuration
- infrastructure-as-code review
Deliverables
- release checklist
- baseline configuration
Outcome: every release meets the agreed security level.
Stage 07 of 07
Maintenance and response
After go-live we monitor, manage vulnerabilities and updates, and lessons from incidents feed back into requirements — closing the loop.
What we do
- security monitoring and alerts
- vulnerability and update management
- incident response procedure
Deliverables
- response plan
- update schedule
Outcome: shorter time from detection to fix.
When it makes sense
SSDLC tailored to your situation
Not every team needs all practices at once. We start with those that reduce risk the most.
New product
Requirements and threat model from the first sprint, pipeline gates from the first release.
Existing system
Maturity assessment, testing and a plan to introduce practices without halting development.
IoT and firmware
Secure updates, key management and testing of devices and communications.
Suppliers and subcontractors
Security requirements in supplier contracts and software acceptance.
SSDLC deployment
How we introduce SSDLC in your organisation
We define the specific scope, outcome and responsibilities before work begins.
Maturity assessment
Review of process and practices, e.g. based on OWASP SAMM.
Plan and priorities
The practices that will reduce risk most in your context.
Practice implementation
Pipeline tools, checklists, team workshops.
Measurement and improvement
Vulnerability and fix-time metrics, further iterations.
Related
SSDLC in the wider security context
FAQ
SSDLC questions
What is SSDLC?
It is a software development lifecycle in which security is part of every stage: requirements, design, coding, testing, deployment and maintenance.
Does SSDLC slow the team down?
Automated pipeline gates and clear checklists usually shorten fix times, because bugs are found earlier. We adapt the pace of introducing practices to the team.
Does SSDLC help with NIS2 compliance?
SSDLC provides processes and artefacts that support demonstrating security in the software supply chain. The process alone, however, does not replace a full analysis of regulatory requirements.
Can you implement SSDLC in our team, not just in Arpino projects?
Yes. We assess your current process and propose a plan for introducing practices, tools and training for your team.
How mature is your development process?
Let’s start by assessing practices and risks. You will get priorities and a plan showing which stage to start with.
Need technical help? support@arpino.pl