Sierra vs Thena: Which Is Better in 2026?

Sierra is an AI platform that helps companies build conversational AI agents to elevate their customer experience — handling customer service, answering questions, resolving issues and engaging customers in natural, brand-aligned conversations. Founded by prominent tech leaders, Sierra targets the enterprise opportunity of using advanced AI agents to transform how businesses interact with their customers, going well beyond simple chatbots toward agents that can actually understand and resolve real customer needs.

The platform lets businesses create AI agents tailored to their brand, knowledge and systems. These agents can hold natural conversations across channels, answer questions accurately using the company's information, take actions like processing requests or updating accounts by integrating with backend systems, and escalate to humans when appropriate. The emphasis is on trustworthy, accurate, on-brand agents that companies can confidently put in front of their customers — addressing the reliability and control concerns that hold many businesses back from deploying AI in customer-facing roles.

Sierra is aimed at companies that want to improve customer experience and efficiency at scale, deploying AI agents that resolve a meaningful share of customer interactions while maintaining quality and brand voice. As AI agents rapidly mature and customer expectations for fast, helpful service rise, platforms that let enterprises build capable, safe, results-driven conversational agents are increasingly valuable. Sierra has positioned itself at the forefront of this shift, with significant attention and backing reflecting the size of the opportunity. For businesses that see AI as a way to deliver better customer experiences — and want a platform to build reliable, branded conversational agents that genuinely help customers — Sierra offers an ambitious, enterprise-grade solution at the cutting edge of applied conversational AI.

Thena is a customer support and operations platform built for B2B companies that support their customers through shared Slack and Microsoft Teams channels. As more B2B relationships move communication into Slack Connect and Teams channels, support requests, questions and issues increasingly come through chat rather than traditional ticketing — and managing that effectively is hard. Thena turns these conversations into a structured, trackable, AI-assisted support workflow, so nothing gets missed and teams can deliver excellent, organized support where their customers actually talk to them.

The platform sits on top of your shared channels and helps you manage them like a real support operation: detecting and tracking requests, assigning and prioritizing them, ensuring timely responses, and giving visibility into what's happening across all your customer channels. It uses AI to help triage and respond, surface insights, and reduce the manual overhead of keeping up with many conversations. By bringing ticketing-like structure and intelligence to chat-based support, Thena solves a real problem for B2B teams whose customers expect to reach them in Slack or Teams but who need the accountability and tracking of a proper support system.

Thena is aimed at B2B SaaS companies and others whose customer relationships and support happen heavily in shared messaging channels, and who want to manage that professionally rather than letting requests slip through informal chats. It connects to the broader support and CRM stack so customer context and data flow where they're needed. As B2B communication continues shifting into Slack and Teams, and as AI makes managing those conversations smarter, platforms that bring order and intelligence to channel-based support are increasingly valuable. For B2B companies that support customers in Slack or Teams and want a structured, AI-assisted way to manage it, Thena offers a focused, modern and genuinely useful solution.