Core Mission: Transform sales training from delayed, subjective roleplays into continuous, sub-700ms real-time AI simulations with immutable performance MRI audits.

Traditional Sales Training (Bottlenecked):
Manual Manager Roleplay ──► Subjective Feedback ──► Days Delay ──► Slow Ramp (8-12 weeks)

AI Sales Coach Architecture (Automated & Real-Time):
24/7 AI Voice Prospect ──► Sub-700ms In-Flight HUD ──► 5-Pillar MRI ──► Rapid Ramp (2 weeks)

Platform Ecosystem:
├── ai-coach (AI Sales Coach: Roleplay, Live Coaching Tips, MRI Audits)
└── meeting-summarizer (Meeting Intelligence: Summaries, Action Items, Email Dispatch)

1. Step 1: Call Type & Persona Selection: Choose between Cold Call, Discovery, Product Demo, Negotiation, or Renewal.
2. Step 2: Difficulty & Prospect Temperament: Select prospect skepticism, gatekeeper presence, and objection hostility.
3. Step 3: Goal Definition & Context Injection: Define measurable call objectives (e.g., "Secure 15-min discovery meeting next Tuesday") and industry constraints.

1. Persona SelectionSelect scenario, industry, and prospect persona profile.

2. Difficulty TierConfigure objection resistance, budget limits, and pacing.

3. Goal DefinitionDefine measurable targets to evaluate goal achievement.

@Injectable()
export class CoachingService {
  private readonly sessionTipsCache = new Map<string, SessionCacheEntry>();
  private readonly CACHE_TTL = 4 * 60 * 60 * 1000; // 4 hours
  private readonly SIMILARITY_THRESHOLD = 0.3; // Stricter word overlap threshold

  constructor(
    private configService: ConfigService,
    private prisma: PrismaService,
    private creditsService: CreditsService,
  ) {
    // Proactive background cache pruning
    setInterval(() => this.pruneCache(), 30 * 60 * 1000).unref();
  }

  private isDuplicateTip(sessionId: string, newTip: string): boolean {
    const entry = this.sessionTipsCache.get(sessionId);
    if (!entry) return false;

    return entry.tips.some(existingTip => 
      this.calculateSimilarity(existingTip, newTip) > this.SIMILARITY_THRESHOLD
    );
  }
}

1. Strategic Presence (0-100): Pacing, clarity, confidence, absence of filler words, and optimal talk-to-listen balance.
2. Discovery Mastery (0-100): Skill in uncovering root causes, asking open-ended questions, and identifying implicit pain signals.
3. Value Alignment (0-100): Anchoring product capabilities directly to business ROI and the prospect's personal objectives.
4. Resilience & Objections (0-100): Professionalism in acknowledging concerns (LAER method) without becoming defensive.
5. Closing Discipline (0-100): Securing time-bound, definitive next steps rather than ambiguous follow-ups.
6. Goal Achievement (0-100): Objective grading on whether the trainee accomplished the specific predefined goal set before the call.

// Word-level talk ratio calculation and composite score aggregation
const traineeWords = conversationText.toLowerCase().split(/\s+/).filter(Boolean).length;
const totalWords = conversationText.split(/\s+/).filter(Boolean).length;
const talkRatio = totalWords > 0 ? (traineeWords / totalWords) * 100 : 50;

const overallScore = [
  result.performance.goalAchievement,
  result.performance.presence,
  result.performance.discovery,
  result.performance.value,
  result.performance.resilience,
  result.performance.closing
].reduce((sum, score) => sum + score, 0) / 6;

• Trainee Trends: Rolling average tracking across pillars (improving, declining, stable).
• Recurring Weaknesses: Pattern clustering identifying chronic bad habits across calls.
• Org Maturity Score: Floor-wide capability rating (0-100) calculated by aggregating all active team member scores.
• Skill Tier Classification: Expert ($\ge 80$), Proficient ($50 - 79$), Critical Needs ($< 50$).

• Sales managers issue 6-character ephemeral access codes (e.g. TX-8921) with configurable maximum usage limits and expiration windows.
• Candidates take standardized live voice assessments without creating accounts or entering credit cards.
• The platform resolves credit deductions dynamically to the issuing manager's balance via guestSession.accessCode.ownerId.

Candidate Flow:
Manager Issues PIN ──► Candidate Enters Code ──► Live Assessment ──► Proxy Credit Deducted from Manager

// Atomic balance modification with audit trail
async deductCredits(
  userId: string,
  platformSlug: string,
  action: string,
  description?: string
): Promise<CreditBalance> {
  const cost = this.getActionCost(platformSlug, action);
  
  const balance = await this.prisma.creditBalance.findUnique({
    where: { userId },
  });

  if (!balance || balance.credits < cost) {
    throw new BadRequestException('Insufficient credits for this operation');
  }

  const newBalance = balance.credits - cost;

  // Execute atomic multi-table write
  const [updatedBalance] = await this.prisma.$transaction([
    this.prisma.creditBalance.update({
      where: { userId },
      data: { credits: newBalance },
    }),
    this.prisma.creditTransaction.create({
      data: {
        userId,
        type: 'usage',
        amount: -cost,
        balance: newBalance,
        platformSlug,
        action,
        description,
      },
    }),
  ]);

  return updatedBalance;
}

1. Ultra-Low Latency In-Flight Voice Coaching: Implemented client-side WebRTC audio streams via Vapi coupled with rolling 4-turn transcript windowing and keyword-based regex fast-paths on the backend. Employed token-streamed Server-Sent Events (SSE) directly to the HUD overlay.
2. Multi-Role Billing Attribution for Ephemeral Guest Testing: Engineered a recursive credit proxy resolver in NestJS. Every session dynamically inspects its caller context: session.userId || guestSession.accessCode.ownerId. Deductions, usage logs, and rate limits transparently bind to the administrator's balance.
3. Dual Subscription & Usage Ledger Integrity: Encapsulated credit modifications inside Prisma $transaction blocks with balance verification, writing dual entries (CreditTransaction audit log + CreditBalance ledger update) in a single atomic database execution.

• ⚡ 75% Faster Rep Ramp Time: New sales representatives reach quota readiness in 2 weeks instead of 8 weeks.
• 🎯 42% Improvement in Discovery Depth: Automated MRI audits forced reps to abandon surface-level feature pitches in favor of problem discovery.
• 💰 100% Automated Monetization: Zero-touch subscription management, automatic seat upgrades, and instant credit renewals via Stripe webhook orchestration.
• 🔒 Enterprise Candidate Screening: Streamlined hiring pipelines by evaluating hundreds of sales applicants via PIN codes before conducting live manager interviews.