Month 1: Foundation Setup
Define roles and responsibilities, establish severity matrix, set up basic logging and alerting, create initial runbooks
- Role definitions complete
- Severity matrix documented
- Basic alerting operational
security19 min read
Security Incident Response: Startup Preparation Guide
A founder- and engineer-ready handbook to stand up a lightweight, repeatable incident response program—roles, severity definitions, triage flow, evidence handling, communications, AI/LLM-specific incidents, tabletop drills, and metrics. Built to be credible in audits without slowing delivery.
By Security Engineering Team
Summary
Incidents are unavoidable. Chaos is optional. This guide gives you a simple, repeatable incident response program built for startups: clear roles, a 30/60/90 triage flow, evidence handling, internal and external communications, AI/LLM-specific incident playbooks, and a quarterly drill cadence. It's designed to satisfy buyer/audit expectations while preserving engineering velocity.
Why Incident Response Matters
| Response Gap | Business Impact | Risk Level | Financial Impact |
|---|---|---|---|
| No clear incident commander | Extended downtime, chaotic response | High | $50K-$200K per hour of downtime |
| Poor evidence handling | Failed audits, legal liability | Medium | $75K-$300K in legal/compliance costs |
| Inadequate communications | Customer churn, reputation damage | High | $100K-$500K in lost revenue |
| Missing AI incident playbooks | Cost overruns, safety failures | High | $80K-$400K in operational risk |
| No tabletop exercises | Unprepared teams, slow response | Medium | $40K-$150K in productivity loss |
| Poor post-incident learning | Repeated incidents, technical debt | Medium | $60K-$250K in recurring costs |
Core Roles and Responsibilities
| Role | Time Commitment | Key Responsibilities | Critical Decisions |
|---|---|---|---|
| Incident Commander (IC) | 100% during incident | Owns decisions and timeline; sets severity; assigns tasks; watches the clock | Severity classification, external comms approval, resource allocation |
| Technical Lead (TL) | 100% during incident | Leads diagnosis, isolation, and remediation; coordinates with service owners | Technical approach, rollback decisions, containment strategy |
| Scribe | 100% during incident | Captures timeline, decisions, commands run; preserves evidence pointers | Evidence collection scope, documentation standards |
| Communications Lead | 50-70% during incident | Prepares stakeholder updates; coordinates status page and customer comms | Message timing, content approval, audience targeting |
| Legal/Privacy Contact | 20-40% during incident | Advises on regulatory notices, data handling, contractual obligations | Legal notification requirements, external messaging approval |
| Security Analyst | 60-80% during incident | Guides containment vs eradication, forensics, log/evidence integrity | Forensic approach, containment strategy, follow-up controls |
Metrics That Matter
| Metric Category | Key Metrics | Target Goals | Measurement Frequency |
|---|---|---|---|
| Response Speed | Time to IC/TL assignment, Containment time | SEV-1: <10min, SEV-2: <30min, Containment <60min | Per incident |
| Evidence Quality | Evidence completeness, Chain of custody integrity | ≥90% checklist completion, 100% custody tracking | Per incident |
| Communication Effectiveness | Customer update timeliness, Internal notification speed | Within promised windows, SEV-1 <15min | Per incident |
| Learning & Improvement | Postmortem action closure, Tabletop exercise frequency | ≥80% closed in 30 days, Quarterly drills | Monthly |
| AI Incident Readiness | Token cost variance, Guardrail effectiveness | <10% variance, 100% eval coverage | Monthly |
| Program Maturity | Runbook coverage, Team training completion | 100% critical scenarios, Annual certification | Quarterly |
90-Day Implementation Plan
Build incident response capability in phases
Month 2: Process Implementation
Implement triage flow, establish evidence handling, create communications templates, conduct first tabletop
- Triage process tested
- Comms templates ready
- First tabletop completed
Month 3: Refinement & Scaling
Refine based on learnings, add AI-specific playbooks, establish metrics, integrate with compliance
- AI playbooks added
- Metrics dashboard live
- Compliance integration complete
Severity Levels and SLAs
| Severity | Definition | Initial Response Target | Comms Cadence | Escalation Requirements |
|---|---|---|---|---|
| SEV-1 | Customer-visible security incident or confirmed data exposure; ongoing exploitation | IC within 10 minutes; full team engaged | Internal every 30–60 min; external every 60–120 min | Executive team, Legal, Board if material |
| SEV-2 | High-risk vulnerability actively exploited in limited scope; potential data exposure | IC within 30 minutes; core team within 60 minutes | Internal hourly; external if customer impact | Department heads, Legal if data exposure |
| SEV-3 | Suspicious activity, control degradation, or third-party advisory with potential exposure | IC within 4 hours; investigation owner assigned | Daily internal updates until closure | Team leads, Security owner |
Triage Flow: 30/60/90 Minutes
Stabilize fast, decide deliberately, document everything
0–30 Minutes: Stabilize and Scope
Assign IC/TL/Scribe; set provisional severity; snapshot critical logs/metrics; isolate blast radius
- Severity set; owners assigned
- Initial containment actions executed
- Evidence collection started
30–60 Minutes: Contain and Verify
Block indicators of compromise; rotate exposed credentials; validate with logs; decide on external comms
- Indicators enumerated and blocked
- Evidence pointers recorded
- Comms plan finalized
60–90 Minutes: Eradicate and Communicate
Patch/rollback/fix configuration; increase monitoring; confirm path to recovery; publish updates
- Remediation actions applied
- Stakeholder updates sent
- Recovery timeline established
Evidence Handling and Forensics
Preserve Before Fix
Snapshot key logs/metrics, relevant database metadata, and configuration states before mutation
- Forensic integrity
- Audit defensibility
- Accurate root cause
Chain of Custody
Designate a single evidence owner. Use append-only storage or write-once buckets with timestamps
- Tamper resistance
- Clear accountability
- Legal readiness
Scoped Collection
Collect only what's necessary: auth logs, admin actions, data export logs, infra events
- Privacy respect
- Faster analysis
- Lower legal risk
Retain and Label
Retain evidence per policy (e.g., 12–24 months). Label with incident ID, severity, and classification
- Searchability
- Policy alignment
- Future reviews
AI-Specific Evidence
Capture prompt/response logs, model outputs, guardrail triggers, token usage patterns
- AI incident analysis
- Model behavior tracking
- Cost attribution
Automated Collection
Automate evidence collection for common incident types to ensure consistency and speed
- Faster response
- Consistent process
- Reduced human error
AI/LLM Incident Playbooks
| Incident Type | Detection Signals | Containment Actions | Recovery Steps |
|---|---|---|---|
| Prompt Injection/Data Leakage | Guardrail triggers, abnormal output, data pattern alerts | Disable risky tools, scrub prompts, redact logs, rotate tokens | Review prompts, enhance filters, update training data |
| Model/Provider Outage | API errors, timeout spikes, provider status alerts | Failover to backup provider, switch models, degrade gracefully | Post-event vendor review, improve abstraction layer |
| Hallucination/Safety Regression | Eval failures, user reports, quality metrics degradation | Block release, rollback model version, increase safety filters | Add targeted tests, update evaluation criteria |
| Runaway Token Spend | Budget alerts, cost spikes, usage pattern anomalies | Enforce budgets, cut off abusive patterns, implement caching | Optimize prompts, review caching strategy, set tighter limits |
Cost Analysis and Budget Planning
| Cost Category | Small Team ($) | Medium Team ($$) | Large Team ($$$) |
|---|---|---|---|
| Team Training & Certification | $15K-$35K | $35K-$85K | $85K-$200K |
| Tools & Infrastructure | $20K-$50K | $50K-$120K | $120K-$280K |
| Consulting & External Support | $25K-$60K | $60K-$150K | $150K-$350K |
| Tabletop Exercises & Drills | $10K-$25K | $25K-$60K | $60K-$140K |
| Incident Response Retainer | $30K-$70K | $70K-$170K | $170K-$400K |
| Total Budget Range | $100K-$240K | $240K-$585K | $585K-$1.37M |
Risk Management Framework
| Risk Category | Likelihood | Impact | Mitigation Strategy | Owner |
|---|---|---|---|---|
| Role Confusion During Incident | High | High | Clear role definitions, regular training, backup assignments | Incident Commander |
| Evidence Handling Errors | Medium | High | Standardized procedures, automated collection, training | Security Analyst |
| Communication Breakdown | High | Medium | Template library, escalation matrix, regular drills | Communications Lead |
| AI Incident Misclassification | Medium | High | Specialized playbooks, AI-trained responders, vendor coordination | Technical Lead |
| Regulatory Notification Failures | Low | High | Legal playbook integration, notification checklists, expert review | Legal/Privacy Contact |
| Team Burnout | Medium | Medium | Rotation schedules, psychological safety, post-incident support | Engineering Manager |
Anti-Patterns to Avoid
All-Hands for Every Alert
Using full team mobilization for minor incidents causes fatigue and reduces effectiveness
- Targeted response
- Reduced burnout
- Better resource allocation
Fixing Before Preserving Evidence
Rushing to fix problems without proper evidence collection compromises forensic integrity
- Better root cause analysis
- Legal defensibility
- Audit compliance
Oral History and Heroics
Relying on individual knowledge rather than documented runbooks and procedures
- Consistent response
- Knowledge retention
- Scalable operations
Vague Customer Communications
Providing unclear or delayed updates to customers during incidents damages trust
- Transparency
- Customer retention
- Brand protection
Skipping Postmortems
Failing to capture and act on lessons learned leads to repeated incidents
- Continuous improvement
- Risk reduction
- Team learning
AI Features Without Guardrails
Deploying AI capabilities without proper safety controls and incident procedures
- Risk management
- Cost control
- User safety
Prerequisites
- Named security owner and incident roles with on-call paths
- Centralized logging and alerting baseline with evidence storage
- Runbooks and communications templates accessible to responders
- Awareness of AI/LLM features, providers, and data flows for playbooks
References & Sources
- NIST SP 800-61 Rev. 2 - Computer Security Incident Handling Guide— Comprehensive framework for security incident response and handling
- SANS Institute Incident Handler's Handbook— Practical guide for security incident response procedures and best practices
- CIS Critical Security Controls v8— Prioritized cybersecurity actions for effective incident response capability
- ISO/IEC 27035-1:2023 Information security incident management— International standard for information security incident management principles
- OWASP AI Security and Privacy Guide— Framework for securing AI systems and handling AI-specific incidents
Related Articles
Technology Stack Upgrade Planning and Risks
Ship safer upgrades—predict risk, tighten tests, stage rollouts, and use AI where it helps
Read more →Technology Stack Evaluation: Framework for Decisions
A clear criteria-and-evidence framework to choose and evolve your stack—now with AI readiness and TCO modeling
Read more →Technology Risk Assessment for Investment Decisions
Make risks quantifiable and investable—evidence, scoring, mitigations, and decision gates
Read more →Technology Due Diligence for Funding Rounds
Pass tech diligence with confidence—evidence, not anecdotes
Read more →Security Compliance Timeline: What to Implement When
A staged plan for implementing security and compliance without killing speed
Read more →Be Incident-Ready in 30 Days
Stand up roles, runbooks, and drills that reduce risk and downtime—AI safety, evidence handling, and buyer/audit expectations included.