Short answer — the best AI tools depend on what you want to automate. Below are top, battle‑tested options grouped by use case (with quick pros/cons and sources), plus compliance and rollout tips.

Enterprise end‑to‑end (video + assessments + ethical AI)

• HireVue (includes Modern Hire capabilities after the 2023 acquisition) — full platform for on‑demand video interviews, automated scoring, assessments and conversational AI; strong enterprise integrations and selection‑science features. Good for large hiring volumes and structured interviewing, but evaluate privacy / bias controls carefully. (hirevue.com, cmswire.com)

High‑volume conversational screening and scheduling (chatbots + automated interviews)

• Humanly — AI agents that chat, screen, schedule and run pre‑screen interviews at scale; strong ATS integrations and designed for high‑volume roles. Good for fast response and candidate engagement. (humanly.io)
• Paradox (Olivia) — SMS/text conversational assistant that captures applicants, screens, and books interviews automatically; widely used for retail/restaurant/shift hiring. (paradox.ai)

Asynchronous one‑way video interviewing (simple, low friction)

• Spark Hire / HireFlix — easy, cost‑effective one‑way (recorded) interview platforms for screening; fast to set up and good for non‑technical roles. Use when you want low friction for candidates. (sparkhire.com)
• VidCruiter — enterprise interview management with pre‑recorded and live video plus automated workflows and reporting. (vidcruiter.com)

Structured pre‑employment assessments and DEI‑focused tools

• Harver — validated, job‑specific assessments (cognitive, SJTs, simulations) plus structured interview workflows — good for predictable, fair job‑fit screening at scale. (harver.com)
• Knockri — video/audio response assessments that focus on transcript/behavioral analysis (designed to reduce bias by avoiding facial‑expression scoring). Good for companies prioritizing fairness/transparency. (en.wikipedia.org)

Technical / coding interviews

• CodeSignal — collaborative IDE, automated scoring, realistic tasks and benchmarking (good for data‑science, full‑stack, and role‑specific coding work). (codesignal.com)
• HackerRank and Codility — established coding interview platforms with live and take‑home evaluations, candidate replays and large question libraries. Pick one based on language support, scoring model and candidate experience you prefer. (hackerrank.com, codility.com)

Emerging/AI agent players (experimental / cutting edge)

• Several new startups (e.g., OptimHire and similar “recruiter AI” products) are building autonomous screening/interview agents — promising for rapid scaling but still early; trial carefully. (businessinsider.com)

Compliance, fairness and risk (do not skip)

• Federal guidance and enforcement bodies expect employers to validate AI hiring tools for adverse impact, keep human oversight, and document job‑relatedness and business necessity. Budget time and resources for validation, vendor audits, and candidate accommodations. (EEOC and DOL/OFCCP guidance.) (eeoc.gov, dol.gov)

Quick selection checklist (use when evaluating vendors)

• Integrations: ATS, SSO, calendar and HRIS compatibility.
• Evidence & validation: published validation studies, IO psychology backing, adverse‑impact testing.
• Transparency: explainability of scores, what data is analyzed (text only vs. audio vs. video/biometrics).
• Candidate experience: mobile access, languages, accessibility accommodations, opt‑out options.
• Security & privacy: SOC/ISO/GDPR/CCPA posture and biometric data handling policies.
  (Many vendors publish these details on product pages—ask for documentation.) (cmswire.com, vidcruiter.com)

Practical rollout tips

• Pilot: run a small, representative pilot and measure time‑to‑hire, quality‑of‑hire, candidate NPS and adverse‑impact metrics before full roll‑out.
• Human‑in‑the‑loop: keep humans making final selection decisions and review AI flagged candidates/questionable results.
• Communication: tell candidates when AI will be used, what data is collected, and provide accommodations/alternatives.
• Audit & monitor: log outcomes and re‑test selection tools periodically for drift and disparate impact. (These are standard best practices recommended by regulators.) (eeoc.gov, laborandemploymentlawcounsel.com)

If you want, I can:

• produce a 1‑page vendor scorecard (features, integrations, compliance checklist) for the top 3 vendors that match your hiring profile (e.g., enterprise vs. SMB, technical vs. non‑technical), or
• draft candidate‑facing language and consent text for using AI in interviews.

(If you’d like either, tell me which hiring scenario you care about and I’ll prepare it.)