certitude.

What do they actually do

certitude trains a personal AI model for each user that can draft messages in their tone, remember context across conversations, and make writing decisions similar to how the user would. These models plug into existing tools via API to automate repetitive writing tasks without changing the user’s voice (certitude site; YC company page).

The team also offers a desktop "test bench" to try the model in any text field and supports direct API integrations so teams can embed the capability in email, CRMs, and helpdesks (YC company page).

Who are their target customer(s)

• Sales reps doing cold outreach and account executives: They spend much of their time drafting similar messages and struggle to keep outreach personalized and on‑brand at higher volumes. A per‑user model helps delegate writing while preserving personal tone and memory across messages (YC/certitude).
• Customer support and success agents: They rewrite similar answers all day, which slows response times and creates inconsistency. Per‑user models with a memory layer can generate repeatable, on‑tone replies that slot into existing tools via API (YC/certitude).
• Founders and executives communicating across email, social, and docs: They lack time to draft everything and risk losing authenticity when delegating or using generic templates. A personal model aims to write in their voice and make choices they would, keeping messages consistent without hands‑on drafting (YC/certitude).
• Recruiting and hiring teams: High‑volume candidate outreach and follow‑ups are time‑consuming and error‑prone, with dropped threads. A model with universal memory can maintain context and speed follow‑ups across tools (YC/certitude).
• Small marketing/content teams producing frequent short copy: They need consistent voice across channels but can’t rewrite or QA everything, causing brand drift and slow launches. API‑first per‑user models let team members automate on‑brand copy while preserving individual style (certitude; YC/certitude).

How would they acquire their first 10, 50, and 100 customers

• First 10: Run hands‑on pilots via the founders’ network: a free 2–4 week concierge setup that trains each user’s model, integrates it into an inbox/CRM, and iterates with live feedback; capture quotes and workflow screenshots for proof (YC/certitude; certitude).
• First 50: Scale with targeted outreach to sales, recruiting, and CS leaders offering a no‑risk 30‑day pilot using preset templates and one integration (Gmail/HubSpot/helpdesk), plus a turnkey onboarding checklist; package best results as a one‑pager and short video, and add a small referral credit (YC/certitude).
• First 100: Productize onboarding with self‑serve provisioning of per‑user models, a template library, and automated emails; hire one SDR for inbound and one CS rep for paid pilots/churn prevention; launch one CRM/helpdesk marketplace app and a reseller program with enablement agencies (certitude; YC/certitude).

What is the rough total addressable market

Top-down context:

In the U.S., there are about 13.38M workers in Sales and Related Occupations and roughly 2.81M Customer Service Representatives, plus about 944k Human Resources Specialists (includes recruiters), many of whom do high‑volume written communication (BLS Sales, May 2023; BLS CSR, 2024; BLS HR Specialists, 2024).

Bottom-up calculation:

Focus on U.S. sales, CS, and recruiting roles as initial TAM: 13.38M + 2.81M + 0.94M ≈ 17.1M workers. Assume 30% are in outbound or ticket‑heavy workflows that benefit from per‑user writing models ≈ 5.1M eligible seats. At $75/user/month ($900/year), TAM ≈ 5.1M × $900 ≈ $4.6B/year.

Assumptions:

• Pricing averages $75 per user per month for per‑user models with API access.
• About 30% of sales, CS, and HR/recruiting roles are heavy, repetitive writers who would adopt a personal writing model.
• TAM reflects the U.S. only; international expansion would increase the total.

Who are some of their notable competitors

• Writer: Enterprise AI writing platform with brand voice and guardrails for teams; overlaps on on‑brand copy generation for marketing and support content.
• Regie.ai: AI for sales sequences and personalization; competes on outbound email generation for SDRs/AEs with CRM integrations.
• Lavender: Email assistant that analyzes and helps write sales emails; strong in the sales outreach niche and inbox‑native workflows.
• Intercom (Fin AI): Customer support AI that drafts and automates responses; relevant for ticket replies and CS workflows where on‑tone, consistent answers matter.
• Lindy: Personal AI agent that can act on a user’s behalf; overlaps with the “digital twin” concept for automating personal tasks and communications.