Senior Fullstack Engineer, Solve

Job Description About the Role Join us at Zendesk, where we're on a mission to power exceptional service for every person on the planet. We're accelerating that ambition by building products rooted in AI, automation, and intelligent customer experiences, because behind every interaction lies an opportunity to make a human connection. We’re seeking a Senior Fullstack Engineer to help build Solve — an AI-powered conversation engine that resolves customer issues across channels. You’ll deliver end-to-end features spanning LLM integrations, RAG retrieval, workflow orchestration, and polished front-end experiences that customers rely on to automate support. What you’ll be doing ● Extend the multi-turn conversation engine: manage intent routing, context preservation, streaming responses, and human handoff across channel integrations. ● Build and optimize the RAG pipeline: embeddings, semantic retrieval, hybrid ranking, and evidence-based answer construction to reduce hallucinations. ● Architect and implement the visual workflow/prompt builder experience (React) for designing branching conversational flows and tool integrations. ● Integrate with LLM providers through a unified abstraction layer and build specialized prompt strategies for tasks like clarification and validation. ● Create data visualization and analytics surfaces to help customers monitor intent performance and AI impact. ● Maintain high quality via testing, observability, and performance improvements across frontend and backend. Basic qualifications ● 3+ years professional fullstack engineering experience with production ownership. ● Proficiency with Python backend frameworks (FastAPI recommended) and React/TypeScript frontends. ● Experience with search, caching, and message/event streaming technologies. Preferred qualifications ● Previous experience with LLM providers (OpenAI, Google GenAI, etc.) and prompt engineering. ● Experience designing visual flow editors (React Flow or similar) and rich text editors. ● Familiarity with embedding stores and retrieval pipelines at scale. ● Prior work on multi-tenant SaaS and real-time streaming systems. The US annualized base salary range for this position is $145,000.00-$217,000.00. This position may also be eligible for bonus, benefits, or related incentives. While this range reflects the minimum and maximum value for new hire salaries for the position across all US locations, the offer for the successful candidate for this position will be based on job related capabilities, applicable experience, and other factors such as work location. Please note that the compensation details listed in US role postings reflect the base salary only (or OTE for commissions based roles), and do not include bonus, benefits, or related incentives. The intelligent heart of customer experience Zendesk software was built to bring a sense of calm to the chaotic world of customer service. Today we power billions of conversations with brands you know and love. Zendesk believes in offering our people a fulfilling and inclusive experience. Our hybrid way of working, enables us to purposefully come together in person, at one of our many Zendesk offices around the world, to connect, collaborate and learn whilst also giving our people the flexibility to work remotely for part of the week. As part of our commitment to fairness and transparency, we inform all applicants that artificial intelligence (AI) or automated decision systems may be used to screen or evaluate applications for this position, in accordance with Company guidelines and applicable law. Zendesk is an equal opportunity employer, and we’re proud of our ongoing efforts to foster global diversity, equity, & inclusion in the workplace. Individuals seeking employment and employees at Zendesk are considered without regard to race, color, religion, national origin, age, sex, gender, gender identity, gender expression, sexual orientation, marital status, medical condition, ancestry, disability, military or veteran status, or any other characteristic protected by applicable law. We are an AA/EEO/Veterans/Disabled employer. If you are based in the United States and would like more information about your EEO rights under the law, please click here . Zendesk endeavors to make reasonable accommodations for applicants with disabilities and disabled veterans pursuant to applicable federal and state law. If you are an individual with a disability and require a reasonable accommodation to submit this application, complete any pre-employment testing, or otherwise participate in the employee selection process, please send an e-mail to with your specific accommodation request.