Technical Debt Management

// Technical Debt Register
interface TechDebtItem {
  id: string;
  title: string;
  description: string;
  category: 'code' | 'architecture' | 'test' | 'docs' | 'dependency' | 'infrastructure';
  severity: 'critical' | 'high' | 'medium' | 'low';

  // Impact Assessment
  impact: {
    developerProductivity: 'none' | 'low' | 'medium' | 'high';
    systemReliability: 'none' | 'low' | 'medium' | 'high';
    securityRisk: 'none' | 'low' | 'medium' | 'high';
    scalability: 'none' | 'low' | 'medium' | 'high';
    onboardingDifficulty: 'none' | 'low' | 'medium' | 'high';
  };

  // Cost of Delay (interest)
  interestRate: string; // e.g., "2 hours/week of developer time wasted"
  accumulatedInterest: string; // e.g., "~100 hours over past 6 months"

  // Fix
  estimatedEffort: string;
  proposedSolution: string;
  dependencies: string[];

  // Tracking
  createdDate: Date;
  owner: string;
  status: 'identified' | 'planned' | 'in-progress' | 'resolved';
  resolvedDate: Date | null;
}

const techDebtRegister: TechDebtItem[] = [
  {
    id: 'TD-001',
    title: 'Monolithic user service needs decomposition',
    description: 'The user service handles auth, profiles, preferences, and notifications. It is the bottleneck for every feature and every deploy.',
    category: 'architecture',
    severity: 'high',
    impact: {
      developerProductivity: 'high',
      systemReliability: 'medium',
      securityRisk: 'low',
      scalability: 'high',
      onboardingDifficulty: 'medium'
    },
    interestRate: '5 hours/week in coordination overhead and deployment conflicts',
    accumulatedInterest: '~260 hours over past year',
    estimatedEffort: '6-8 weeks for 2 engineers',
    proposedSolution: 'Extract auth into separate service, then notifications, then preferences. Use event-driven communication between services.',
    dependencies: ['Need API gateway first (TD-005)'],
    createdDate: new Date('2024-01-15'),
    owner: 'Tech Lead',
    status: 'planned',
    resolvedDate: null
  },
  {
    id: 'TD-002',
    title: 'Test coverage below 40% on payment module',
    description: 'The payment module has 38% test coverage. Changes frequently cause regressions that are caught in production.',
    category: 'test',
    severity: 'critical',
    impact: {
      developerProductivity: 'medium',
      systemReliability: 'high',
      securityRisk: 'medium',
      scalability: 'none',
      onboardingDifficulty: 'high'
    },
    interestRate: '3 production incidents per quarter, each costing 8-16 hours to resolve',
    accumulatedInterest: '~120 hours of incident response this year',
    estimatedEffort: '3 weeks for 1 engineer',
    proposedSolution: 'Write integration tests for all payment flows. Add mutation testing. Set up CI gate to prevent coverage regression.',
    dependencies: [],
    createdDate: new Date('2024-02-01'),
    owner: 'Backend Team',
    status: 'in-progress',
    resolvedDate: null
  }
];

// Prioritize tech debt using a scoring model
function scoreTechDebt(item: TechDebtItem): number {
  const impactScores: Record = {
    'none': 0, 'low': 1, 'medium': 3, 'high': 5
  };

  const totalImpact = Object.values(item.impact)
    .reduce((sum, level) => sum + impactScores[level], 0);

  const severityMultiplier: Record = {
    'critical': 4, 'high': 3, 'medium': 2, 'low': 1
  };

  return totalImpact * severityMultiplier[item.severity];
}