CTO Advisor

Technical leadership advisory for Chief Technology Officers.

Core Competencies

• Technology strategy and vision
• System architecture and design
• Engineering team building and scaling
• Technical debt management
• Build vs buy decisions
• Security and compliance
• Platform and infrastructure
• Vendor and technology evaluation

Architecture Decision Framework

Decision Record Template (ADR)

# ADR-[NUMBER]: [TITLE]

## Status
[Proposed | Accepted | Deprecated | Superseded]

## Context
[What is the issue we're facing?]

## Decision
[What is the change we're proposing?]

## Consequences
[What becomes easier or harder?]

## Alternatives Considered
[What other options were evaluated?]

Technology Evaluation Matrix

Criteria	Weight	Option A	Option B	Option C
Technical Fit	25%
Team Capability	20%
Scalability	20%
Total Cost	15%
Vendor Risk	10%
Community/Support	10%

Technical Debt Management

Debt Classification

Type 1: Deliberate Tactical

• Conscious shortcuts for speed
• Known cleanup required
• Documented with timeline
• Example: Hardcoded config for MVP

Type 2: Accidental/Outdated

• Requirements changed after build
• Technology evolved
• Better patterns emerged
• Example: Legacy API design

Type 3: Bit Rot

• Dependencies outdated
• Security vulnerabilities
• Performance degradation
• Example: Unpatched libraries

Debt Prioritization Formula

Priority Score = (Impact × Reach × Urgency) / Effort

Impact: 1-5 (business/security/reliability impact)
Reach: 1-5 (how much of system affected)
Urgency: 1-5 (time sensitivity)
Effort: 1-5 (engineering investment required)

Debt Budget

Allocate engineering capacity to debt:

• Startup (< 20 engineers): 10-15%
• Growth (20-100 engineers): 15-20%
• Scale (100+ engineers): 20-25%

Engineering Team Scaling

Team Structure by Size

5-15 Engineers:

• Single team, full-stack ownership
• CTO as technical lead
• Informal processes
• Everyone deploys

15-40 Engineers:

• 2-4 feature teams
• Engineering managers introduced
• Sprint/kanban processes
• On-call rotation begins

40-100 Engineers:

• Platform team split out
• Tech leads per team
• Architecture review board
• Formal RFC process

100+ Engineers:

• Multiple domains/pillars
• Principal engineers
• Developer experience team
• Internal tooling investment

Hiring Bar

Junior (0-2 years):

• Strong fundamentals
• Learning velocity
• Culture fit
• Mentorship capacity available

Mid-Level (2-5 years):

• Independent delivery
• Code quality focus
• Collaboration skills
• Can own features end-to-end

Senior (5+ years):

• System design capability
• Technical leadership
• Mentoring others
• Cross-team influence

Staff+ (8+ years):

• Organizational impact
• Technical vision
• Executive communication
• Industry perspective

Interview Process

1. Resume Screen: Technical background check
2. Phone Screen: Communication and basic skills
3. Technical Interview: Coding and problem solving
4. System Design: Architecture and trade-offs
5. Team Fit: Collaboration and culture
6. Reference Check: Verification and red flags

Platform Strategy

Build vs Buy Framework

Build When:

• Core differentiator
• Unique requirements
• Long-term strategic value
• Sufficient engineering capacity
• Acceptable timeline

Buy When:

• Commodity capability
• Standard requirements
• Faster time to market
• Cost effective at scale
• Vendor ecosystem strong

Technology Radar

Categorize technologies into:

Adopt: Use in production
Trial: Use in limited scope
Assess: Explore and evaluate
Hold: Do not start new work

Review quarterly with engineering leadership.

Security Framework

Security Layers

Application Security:

• Input validation
• Authentication/authorization
• Secrets management
• Dependency scanning

Infrastructure Security:

• Network segmentation
• Encryption in transit/at rest
• Access controls
• Audit logging

Operational Security:

• Incident response
• Vulnerability management
• Penetration testing
• Security training

Compliance Checklist

• SOC 2 Type II
• GDPR compliance
• Data classification
• Access reviews (quarterly)
• Penetration testing (annual)
• Security awareness training
• Incident response plan
• Business continuity plan

Engineering Metrics

Productivity Metrics

DORA Metrics:

• Deployment Frequency
• Lead Time for Changes
• Mean Time to Recovery
• Change Failure Rate

Targets by Maturity:

Metric	Low	Medium	High	Elite
Deploy Freq	Monthly	Weekly	Daily	On-demand
Lead Time	> 6 months	1-6 months	1 week-1 month	< 1 day
MTTR	> 6 months	1 day-1 week	< 1 day	< 1 hour
Change Fail	> 46%	16-30%	0-15%	0-15%

Quality Metrics

• Test coverage percentage
• Bug escape rate
• P0/P1 incident frequency
• Technical debt ratio
• Documentation coverage

System Design Principles

Scalability Patterns

Horizontal Scaling:

• Stateless services
• Load balancing
• Database sharding
• Cache layers

Vertical Scaling:

• Resource optimization
• Query optimization
• Memory management
• Connection pooling

Reliability Patterns

Fault Tolerance:

• Circuit breakers
• Retry with backoff
• Graceful degradation
• Bulkhead isolation

Observability:

• Structured logging
• Distributed tracing
• Metrics collection
• Alerting thresholds

Common Scenarios

Scenario: Major Outage

Response sequence:

1. Acknowledge and assemble team
2. Identify scope and impact
3. Implement mitigation
4. Communicate to stakeholders
5. Resolve root cause
6. Conduct post-mortem
7. Implement preventive measures

Scenario: Security Incident

Response sequence:

1. Contain the breach
2. Preserve evidence
3. Assess data exposure
4. Notify legal/compliance
5. Remediate vulnerability
6. External notification if required
7. Post-incident review

Scenario: Acquisition Due Diligence

Preparation checklist:

• System architecture documentation
• Technology inventory
• Security audit reports
• Scalability assessment
• Technical debt inventory
• Key personnel dependencies
• IP and licensing review

Reference Materials

• references/architecture_patterns.md - System design patterns
• references/security_framework.md - Security best practices
• references/scaling_playbook.md - Team and system scaling
• references/tech_evaluation.md - Technology assessment guide

Scripts

# Technical debt analysis
python scripts/tech_debt_analyzer.py --repo /path/to/repo

# Team scaling calculator
python scripts/team_scaling.py --current 25 --growth-rate 0.5

# Architecture diagram generator
python scripts/arch_diagram.py --services services.yaml

# Security scan orchestration
python scripts/security_scan.py --target production