Full-Time
Software Engineer - New Grad
Agent
Posted on 9/26/2025
Sierra
501-1,000 employees
AI agents for real-time customer support
Compensation Overview
£140k - £150k/yr
London, UK
In Person
 Software Engineering |
|---|
Get referred to Sierra
See people who can refer or advise you
- Experience building and scaling end-to-end production systems.
- Strong technical problem-solving skills, especially in fast-changing, ambiguous environments.
- A builder and tinkerer’s mindset with high agency.
- Comfort working directly with customers to understand their needs and solve real-world problems.
- Excellent communication skills - clear, direct, and persuasive across technical and non-technical audiences.
- Design and deliver production-grade AI agents: You'll build and ship highly performant, reliable, and intuitive AI agents that are central, mission-critical and drive revenue directly to Sierra's growth. These aren't prototypes—they are powerful, scalable systems running in production environments across industries like finance, healthcare, and commerce.
- Drive the Agent Development Life Cycle (ADLC): You'll have complete ownership and autonomy from initial pilot through deployment and continuous iteration. You'll be responsible for building, tuning, and evolving AI agents in production environments, defining the standard for ADLC best practices along the way.
- Partner with large enterprises and cutting-edge startups: You’ll work directly with leaders at some of the world’s largest enterprises to understand their most pressing business challenges, and build AI agents that transform how they operate at scale. You'll also partner with the most cutting-edge startups in Silicon Valley, embedding AI agents across their entire business stack to drive innovation and efficiency.
- Build the future of the platform: Your direct work with customers will guide the evolution of Sierra's core platform. You'll surface unmet needs, prototype new tools and features, and collaborate with research, product, and platform to shape the future of AI agent development and Sierra's product.
- Experience building or deploying AI/LLM systems in production.
- Have been a founder or founding engineer - you know what it means to balance craft, ownership, and speed.
- Familiarity with tools that power today's AI agents: eval frameworks, agent tooling, RAG pipelines, and prompt engineering.
- Prior experience with React, TypeScript, and/or Go.
- Previous roles where you interfaced with customers or led technical projects with external stakeholders.
Sierra.ai builds and deploys conversational AI agents for customer service that handle real-time interactions and take actionable steps within a client’s systems (e.g., CRM, order management) to resolve issues. The agents are always-on, empathetic, and aligned with a client’s brand voice, following strict policies and security procedures. They operate deterministically, with built-in quality assurance that reveals the reasoning behind each interaction, ensuring transparency. The platform is subscription-based and scales to large client ecosystems, serving brands like Sonos, SiriusXM, and WeightWatchers, with a reported CSAT of 4.6/5 and a 70% resolution rate. Sierra.ai emphasizes data governance, using client data only to train models and securing it with industry-standard practices. Its goal is to improve customer experience by delivering real-time, automated support that can understand, resolve, and learn from interactions while remaining controllable and auditable.
Company Size
501-1,000
Company Stage
Series E
Total Funding
$1.6B
Headquarters
San Francisco, California
Founded
2023
Get referred to Sierra
See people who can refer or advise you
Simplify's Take
What believers are saying
- May 2026 Series E raised $950 million at a $15 billion valuation.
- July 14, 2026 SoftBank named Sierra exclusive Japan partner after LINEMO hit 97% resolution.
- August 12, 2026 StoreEase partnership extends Sierra into self-storage payments, leasing, and access.
What critics are saying
- June 25, 2026 Salesforce launched Help Agent with pay-per-resolution pricing and native CRM integration.
- SoftBank, Salesforce, and Intercom compress Sierra's differentiation by bundling AI into existing platforms.
- One failed payment or access action at SoftBank or BBVA triggers enterprise defections.
What makes Sierra unique
- Bret Taylor and Clay Bavor give Sierra elite enterprise sales and product credibility.
- July 23, 2026 Horizon adds long-horizon agents for days-long workflows across industries.
- August 25, 2026 Voice Personas combines brand tone, multilingual voice, and controlled actions.
Help us improve and share your feedback! Did you find this helpful?
Benefits
Unlimited Paid Time Off
Medical, Dental, and Vision benefits for you and your family
Life Insurance
Disability Insurance
401(k) Company Match
Parental Leave
Fertility Treatment Support
Discretionary Benefit Stipend
Growth & Insights and Company News
6 month growth
↑ 20%1 year growth
↑ 4%2 year growth
↑ 20%Sophisticated agents for the most demanding companies: Sierra launches in Korea. Bret and I are excited to announce that Sierra is opening an office in Seoul. South Korea is home to some of the world's most complex businesses, across the largest industries, and Sierra is looking forward to serving them. Sierra is the fastest growing customer facing AI platform, and Sierra partner with one in three of the world's leading banks, 40% of the Fortune 50, and companies as diverse as Singtel, SoftBank, LINE MAN Wongnai, Santander, Uber, Hyatt, Gap, Wilson and Sonos. Agents built on Sierra are now moving beyond support - account sign-up and set-up, password resets, troubleshooting, returns, replacing an IVR - to driving key business workflows. Everything from increasing cart sizes to originating mortgages, refinancing loans, and saving subscribers from churning. And because all these agents are driving measurable outcomes, Sierra charge by results not usage. As agents take on more complex work, Bret and I are excited to deliver on the promise of hwandae, that ability to treat guests warmly which separates a good customer experience from a great one. It's the difference between an AI agent simply answering your next question and making you feel genuinely cared for. This is possible when agents can build context over time. Sierra's long running Horizon agents act over weeks, months, even years, and across systems and channels. And they use its Context Engine to learn from every interaction, improve and make better decisions over time. Most importantly, Sierra enables companies to go live in weeks so they can learn and iterate with AI more quickly. * Singtel, Asia's leading communications technology company, went live in 10 weeks with resolution rates of over 70%. * Next, the largest British clothing retailer, went live with their agent in just six weeks and it now covers 48 languages in 83 countries. * BBVA, a leading global bank, launched Sierra's first long running Horizon agent in just 30 days, serving customers in Spain and Argentina. If you're based in Korea and excited about how AI can help you build better customer experiences and drive stronger growth, Sierra'd love to hear from you. 최첨단 기업을 위한 정교한 AI 에이전트: 시에라, 한국 진출하다. 브렛과 함께 시에라가 서울 지사를 설립한다는 기쁜 소식을 전합니다. 대한민국은 주요 산업 전반에 걸쳐 세계에서 가장 복잡하고 정교한 비즈니스들의 본고장이며, 앞으로 이런 기업들과 협력할 날을 고대하고 있습니다. 시에라는 세계에서 가장 빠르게 성장하고 있는 고객 서비스 AI 플랫폼입니다. 전 세계 주요 은행의 3분의 1 및 Fortune 50 기업의 40%와 파트너십을 맺고 있으며, Singtel, SoftBank, LINE MAN Wongnai, Santander, Uber, Hyatt, Gap, Wilson, Sonos 등 다양한 글로벌 기업과 협력하고 있습니다. 시에라가 구축한 에이전트는 이제 고객 지원을 넘어 핵심 비즈니스 업무까지 수행하고 있습니다. 계정 가입 및 설정, 비밀번호 재설정, 문제 해결, 반품, IVR 대체는 물론, 구매 금액 증대, 주택담보대출 실행, 대출 리파이낸싱, 고객 구독 해지 방지까지 담당합니다. 이러한 에이전트들은 측정 가능한 성과를 만들어내며, 시에라는 사용량이 아닌 결과를 기준으로 비용을 책정합니다. 에이전트가 더 복잡한 업무를 맡게 되면서, 시에라는 좋은 고객 경험과 훌륭한 고객 경험을 가르는 힘, 즉 환대의 가치를 실현할 수 있기를 기대합니다. 저희가 생각하는 환대란, 단순한 질의 응답을 넘어, 고객을 진심으로 배려하는 훌륭한 고객 경험입니다. 이는 에이전트가 시간이 지남에 따라 이해도를 높여갈 수 있을 때 가능합니다. 시에라의 장기 실행형 Horizon 에이전트는 수주, 수개월, 수년에 걸쳐 여러 시스템과 채널을 넘나들며 고객과 소통할 수 있습니다. 또한 Context Engine을 통해 모든 상호작용에서 학습하고 각 고객에 대한 이해를 바탕으로, 더 나은 결정을 내립니다. 무엇보다 시에라는 기업들이 단 몇 주 만에 AI 에이전트를 실제 서비스에 도입할 수 있도록 지원합니다. 이를 통해 AI 에이전트를 더 빠르게 학습시키고 개선해 나갈 수 있습니다. * 아시아를 대표하는 통신사 Singtel은 10주 만에 서비스를 시작했으며, 70%가 넘는 해결률을 달성했습니다. * 영국 최대 의류 리테일러 Next는 단 6주 만에 에이전트를 출시했으며, 현재 83개국에서 48개 언어를 지원하고 있습니다. * 세계적인 은행 BBVA는 단 30일 만에 시에라 최초의 장기 실행형 Horizon 에이전트를 출시해 스페인과 아르헨티나 고객에게 서비스를 제공하고 있습니다. AI를 통해 더 나은 고객 경험을 만들고 더욱 강력한 기업 성장을 이루는 데 관심이 있으시다면, 시에라가 여러분과 함께하고 싶습니다.
StoreEase and Sierra partner to bring outcome-driven AI to self-storage. StoreEase's AI agent, built on Sierra, is measured and priced on the outcomes it delivers, not the conversations it just deflects to the office or a callback. Today in New York price on outcomes because that is the only number that aligns its success with its customers' success. When its operators win, Today in New York win" - Josh Boyd, CEO of StoreEase SAN FRANCISCO, NY, UNITED STATES, August 12, 2026 /EINPresswire.com/ - StoreEase, with its AI-native self-storage operating platform EaseOS, today announced its partnership with Sierra, whose platform powers AI agents for customer service, to deliver an AI agent that delivers truly omni-channel service across self-storage operations: the same agent, with the same context and the same rules, on the phone, on the web, and now in the facility lobby itself. Operators deploy the agent under their own brand and name. The agent is broadly integrated with the industry's most popular software systems. The EaseOS platform provides the agent with secure access to a variety of facility management systems, access control vendors, and payment processors that operators already use, allowing for rapid deployment into businesses in as little as two weeks. This gives operators one consistent agent across every point of customer contact, with one unified software and data interface. The partnership launched at the end of 2025. In the months since, StoreEase and Sierra have worked side by side to train the agent across a growing set of customer journeys, refining it on real interactions until it could reliably carry a request all the way to a completed outcome. The choice of Sierra was deliberate. Co-founded by former Salesforce co-CEO and OpenAI board chair Bret Taylor, Sierra has become the enterprise standard for AI customer agents, with a customer base reported to include roughly 40 percent of the Fortune 50 and consumer names such as SiriusXM, Sonos, ADT, and Chime. StoreEase brings that same enterprise-grade foundation to an industry that has never had access to AI of this caliber. The partnership is built on a principle that separates it from most AI deployments: a focus on outcomes, not activity. Too many AI agents claim to automate or contain a conversation when all they really do is deflect it to the office or a callback, keeping the customer from an answer without solving the problem. "The industry has been optimizing the wrong number," said Josh Boyd, CEO of StoreEase. "An automation rate tells you the AI avoided a human. It tells you nothing about whether the customer was helped. We built this partnership around outcomes, a payment made, access restored, a lease signed, because that is what earns a customer's loyalty and grows an operator's revenue." That philosophy extends to pricing. Rather than charging on what it thinks the AI is doing, StoreEase prices the agent on the outcomes it produces. An operator pays for results delivered, not for conversations held or calls deflected. "We price on outcomes because that is the only number that aligns our success with our customers' success. When our operators win, we win," Boyd said. FROM THE RIGHT ANSWER TO THE RIGHT ACTION Where many AI agents stop at conversation, StoreEase's agent completes the journey. Every one of the roughly 30 workflows it runs today ends in an action: posting a payment, checking live inventory, processing move-outs, restoring access after a resolved delinquency, or signing a new lease. Sierra provides the reasoning and the conversation; StoreEase, drawing on its own experience operating facilities, knows which self-storage workflows matter most and how to train the agent to handle them. EaseOS then lets the agent actually act, connecting to the software operators use to run facilities, control access, and take payments, with guardrails built into each action. The results show up on both sides of the ledger. After-hours calls that once ended in voicemail now convert directly, producing hundreds of new leads, a 2 to 3 percent lift in move-ins, and hundreds of thousands of dollars in increased customer lifetime value. On cost, StoreEase has onboarded more facilities while supporting them with fewer people per site. Customer review scores, the metric StoreEase watches most closely, have held steady throughout. AVAILABLE TO THE WHOLE INDUSTRY StoreEase offers the platform beyond its own managed facilities, with integrations to most popular self-storage software. Operators can plug in and see the agent working under their own brand in as little as two weeks. "Self-storage is rarely a fun purchase. People come to us in a moment of need, a move, a downsize, a loss," said David Wu, CTO of StoreEase. "Serve those moments well and a customer stays for years." ABOUT STOREEASE StoreEase is an AI-native self-storage operating platform. Through EaseOS and the Ease Connect, StoreEase brings consistent, high-quality service to every channel a customer uses, helping operators grow revenue and lifetime value while lowering the cost of running a facility. Learn more at www.easeos.ai ABOUT SIERRA Sierra is a conversational AI platform that helps companies build AI agents to deliver better customer experiences and business outcomes. Learn more at sierra.ai. Legal Disclaimer: EIN Presswire provides this news content "as is" without warranty of any kind. Today in New York do not accept any responsibility or liability for the accuracy, content, images, videos, licenses, completeness, legality, or reliability of the information contained in this article. If you have any complaints or copyright issues related to this article, kindly contact the author above.
Introducing Voice Personas. What an agent does and how it expresses itself are two different things. Today, Sierra is launching Voice Personas so you can design both. When Sierra launched Sierra two and a half years ago, the fact that an AI agent could have a phone call was remarkable. Now, its customers have built agents that are handling billions of customer interactions and driving billions of dollars of revenue every year. AI agents are clearly becoming the digital front for its companies. How do Sierra take the next step in making those interactions feel as distinct and differentiated as each of its brands? Personas lets you build your own brand voice. With Personas, you can give your AI agent not just a multilingual voice, but an entire personality. It can be polite, snarky, casual, formal, funny, or serious - in a way that you deeply control and uniquely represents your brand values. A persona isn't simply a voice or a prompt telling an agent to "sound empathetic." It combines voice, personality, and language-aware behavior into one coherent experience. You build the underlying agent once, then give it different personas for different brands, markets, and experiences. The best way to understand Personas is to hear them. Here's a video with a sample of some of its favorites so far: One agent, many personalities. What your agent does often needs to be consistent whatever the channel, language or country. A retailer's return policy doesn't change depending on who is asking. But how an agent communicates can. One brand might want an agent that is calm, measured, and reassuring. Another might want one that is energetic, conversational, and optimistic. Both can follow exactly the same policies and take exactly the same actions while creating very different customer experiences. The same principle applies across cultures. Next, the leading UK retailer, has an agent live in 83 countries and 20 languages. The challenge at that scale isn't simply translation. Expectations around formality, pacing, vocabulary, and conversational style vary around the world. Voice Personas lets a company adapt the interaction itself - without building a different agent for every market. More than a voice. Voice is how a persona comes to life, but Voice Personas goes beyond choosing an accent or a particular character. The agent itself can control how it speaks. New capabilities in the Sierra Agent SDK let agents adjust pacing, respond naturally to interruptions, and even switch voices or languages in the middle of a conversation. Underneath, every persona is powered by a constellation of voice models. Sierra uses the model that performs best for a particular persona, language, and use case, continuously benchmarking leading models as the technology evolves. Voices are sealed in production, so the experience you test is the experience your customers hear. And Voice Personas are integrated with Sierra's simulation and evaluation infrastructure. Teams can test personas against thousands of simulated customer interactions before deploying them, or A/B test different personalities and voices based on the outcomes they produce. Those differences can be significant. For one agent, pairing a natural voice with a persona increased resolution rates by almost 50 percent. Personality without compromise. As voice AI improves, it's easy to focus on making agents sound more human. Sierra think the bigger opportunity is making them feel like your company. By separating what an agent does from how it communicates, one highly effective agent can represent your brand while adapting to different customers, cultures, and markets around the world. While the job stays the same, the personality can change. Voice Personas are available today on Sierra.
CarMax has partnered with Sierra to improve its inbound call experience using AI voice-enabled agents. Deployed in May, Sierra's technology helps customers reach the right destination or associate faster by asking conversational questions to understand their needs. The system provides quick answers to common queries about store hours and vehicle availability. Since launch, CarMax has seen increased call resolution and fewer unresolved calls. The company plans to expand capabilities to include appointment management for appraisals and test drives. The partnership demonstrates CarMax's ongoing commitment to leveraging AI technology. The retailer already operates Skye, its 24/7 virtual assistant, and was the first US auto retailer with a ChatGPT app supporting car shopping.
Sierra and Plaid have announced a partnership to enable AI agents to make payments on behalf of customers. The collaboration aims to ensure secure transactions amid rising cybersecurity threats. Plaid CEO Zachary Perret and Sierra co-founder Clay Bavor discussed the partnership, which focuses on integrating payment capabilities into AI-driven financial services whilst maintaining robust security measures. The companies are working to address safety concerns as AI agents take on more financial responsibilities in consumer transactions.