Member of Technical Staff (Answer Quality & Evals)

We are hiring builders to define how people talk to, show things to, and hear from AI In 2026, we launched Computer, the defining product for the new era of agentic AI. We've scaled beyond the millions of people using Perplexity every day for research, shopping, investing and curiosity into a new paradigm of using AI to transform knowledge into action. The Multimodal team builds the experiences and infrastructure that move AI interaction beyond touch and text — realtime voice, vision, and the platform systems behind them. We own the full path from a user speaking into a device to an answer coming back: the realtime session infrastructure that connects clients to frontier audio models, the backend orchestration that routes, records, and supervises live sessions, and the SDK that powers voice and multimodal experiences across Perplexity's apps. As a backend engineer on Multimodal, you will design and scale the distributed systems that carry live voice sessions in production — and drive entirely new products at the intersection of voice, vision, and agents. Why Perplexity is Different Craftsmanship. We build high quality, tasteful products targeting both the AI native and AI curious. Ownership. You identify the problem, design the solution and ship it. Entrepreneurship. We think like founders, act with urgency, and hustle to deliver for each other and our users. Scholarship. Work among highly talented peers, pursuing knowledge and truth, upleveling ourselves, our teams, and our products. Partnership. We amplify each others' strengths, break down silos, and give selflessly to help our colleagues deliver excellence. What you'll do Design, build, and scale the backend session-worker architecture that powers realtime voice: durable per-session workers, provider routing, and stateful streaming over gRPC. Own distributed-systems problems end-to-end — session lifecycle, crash recovery, reconnection and replay, multi-region deployment, and graceful degradation under real produ

Perplexity is seeking experienced ML engineers to design, build, and optimize the recommendation systems that power core experiences on Perplexity. Perplexity builds AI for those who expect more. Our products are designed to help people find answers, make their most consequential decisions, and complete increasingly ambitious work. Across these use cases, the Perplexity experience must feel deeply personal. Great recommendations and user understanding are central to delighting and delivering for each user. To do this, we are reimagining recommendation systems for the LLM era. Our goal is to combine the intelligence of frontier LLMs, the personalization context that comes from real product usage, and the continual learning capabilities of modern recommendation systems. We build systems that draw on past context and connected data sources to deeply understand each user's needs and recommend the actions that help them get the most out of Perplexity. Why Perplexity is Different Craftsmanship . We build high quality, tasteful products targeting both AI native and AI curious users. Ownership . You identify the problem, design the solution and ship it. Entrepreneurship . We think like founders, act with urgency, and hustle to deliver for each other and our users. Scholarship . Work among highly talented peers, pursuing knowledge and truth, upleveling ourselves, our teams, and our products. Partnership . We amplify each others’ strengths, break down silos, and give selflessly to help our colleagues deliver excellence. What you'll do Own the personalization and ranking behind key product surfaces to make Perplexity more useful and drive impact on core user and business metrics. Build user modeling that captures intent, preference, and propensity, and powers more relevant, more personalized experiences. Design the decision layer that balances competing objectives to produce the best overall experience for the user. Build the data and evaluation foundations that let these syst

About the Role The Infrastructure team builds and operates the foundational systems behind Perplexity’s products. At Perplexity, infrastructure sits on the critical path of every answer, supporting real-time search, retrieval, model serving, and agent workloads where latency, reliability, and rapid iteration directly shape the user experience. This role is for strong infrastructure engineers whose experience spans multiple domains and who are energized by cross-cutting problems that do not fit neatly within a single platform team. You do not need to be a specialist in every area. Scope ranges from owning major production systems to setting technical direction across teams, leading complex infrastructure programs, and shaping infrastructure strategy across the organization. If a specialized Cloud Infrastructure, Storage Platform, Backend Platform, Data Platform, Connector Platform, or AI Acceleration role clearly matches your expertise and interests, apply directly to it. If your experience spans several infrastructure domains or you are most energized by cross-cutting systems problems, apply here. Submit one application, and we will consider you across the Infrastructure organization. Key Responsibilities Own cross-cutting infrastructure problems that span compute, storage, networking, data, deployment, and reliability, including eliminating bottlenecks across retrieval and serving paths, building shared abstractions across deployment environments, and resolving failure modes that cross platform boundaries. Design, build, and operate distributed infrastructure supporting Perplexity’s consumer, AI, and enterprise workloads, owning systems from architecture through production operation. Identify gaps between existing platforms and build shared abstractions, automation, and tooling that make infrastructure easier and safer to use. Improve system performance, availability, scalability, and cost-efficiency across online request traffic and background workloads. Debug com

Perplexity is seeking top-tier AI Research Scientists and Engineers to advance our AI products and capabilities. We're building the future of AI-powered search and agent experiences through our Sonar models, Deep Research Agent, Comet Agent, and Search products. Join us in creating SOTA experiences that handle hundreds of millions of queries and continue to scale rapidly. Team Structure Depending on your interests and expertise, you'll work on one of three specialized teams: 1. Core Research Team (Horizontal) Focus on generating and improving base models that power all our products. This team works on foundational model capabilities, post-training techniques, building RL infra and infrastructure that benefits the entire organization. 2. Agent Products Team (Vertical) Concentrate on fine-tuning and optimizing models for our Deep Research Agent and Labs/Canvas products. This team bridges research and product, ensuring our agent capabilities deliver exceptional user experiences. 3. Comet Agent Team (Vertical) Dedicated to developing and enhancing our Comet Agent product. This specialized team focuses on the unique requirements and optimizations needed for Comet's specific use cases. Responsibilities Research & Development Post-train SOTA LLMs using the latest supervised and reinforcement learning techniques (SFT/DPO/GRPO) Leverage our rich query/answer dataset to scale model performance across Sonar, Deep Research, Comet, and Search products Stay current with the latest LLM research, especially in model training, optimization, and personalization techniques Implement preference optimization and personalization capabilities to enhance user experience Invent in-house improvements and optimizations to enhance SOTA models Turn research ideas into algorithms and run experiments to launch new models Infrastructure & Implementation Own full-stack data, training, and evaluation pipelines required for model development Build robust and effective training frameworks (on

Perplexity is looking for a technical program manager to be the connective tissue between our model providers, engineering, and product teams, driving our core inference platform forward. Perplexity runs one of the highest-throughput inference stacks in the industry, serving Ask, Computer, and API traffic across a large and constantly shifting portfolio of first-party and third-party models. This role sits at the intersection of product, engineering, and finance: you'll orchestrate across model providers and internal teams to keep new models and capacity moving smoothly into production, while executing the roadmap for the inference platform itself. The ideal candidate has strong technical judgment, thrives coordinating across teams and external partners with competing timelines, and is energized by building the operating model for a function that doesn't have much precedent yet. Our Mission Perplexity's mission is to power curiosity. Curious people are the people who drive change in the world. Driving change is a continuous cycle of learning, building, and integrating. Learn: curious people constantly learn new things by asking more. They question the status quo in their own expertise and they constantly learn outside of it. Research is essential to them and never ending. Build: curious people make and create things, to show the world their new answers to problems no one else ever questioned. They take action on what they've learned. Makers need tools to create their products, their companies, their reality. Integrate: they must interact with the world as it is to drive change and adoption. True leaders do not simply build something and hope. They must have armies of agents and workers who can constantly work in millions of small ways. What You'll Do Execute the roadmap for the inference platform request handling, rate limits and quotas, usage controls, and the reliability and observability surface engineering and product teams depend on Be the connective tissue bet

About Us: AI needs a new infrastructure layer. We're building it at Modal. Every era of computing brought new workloads that previous infrastructure couldn't support: mainframes, databases, and the cloud. Each time, the company that rebuilt the layer underneath defined the decade. AI is no different, except it touches everything instead of one slice, and the window to build the layer underneath it is open right now. Our customers include category-defining companies like Ramp , Cognition, DoorDash, and Suno. They rely on Modal for instant GPU access, sub-second container starts, and native storage, so it's simple to serve low-latency inference, fine-tune models, and access production-ready sandboxes at scale. We've passed $1B in annualized run rate, up 15x from a year ago. In October 2026 we raised a $750M Series D led by Accel at a $15.75B valuation. Our team includes creators of popular open-source projects (e.g., Seaborn , Luigi ), academic researchers, international olympiad medalists, and experienced engineering and product leaders with decades of experience. The Role: Modal’s Inference Runtime team owns the container runtime stack used to run inference and training workloads across our fleet. We work at the boundary of Linux, containers, filesystems, storage, GPU drivers, and distributed systems.Our goal is to make demanding ML workloads start quickly, run efficiently, and remain securely isolated — whether they use a single GPU, hundreds of gigabytes of memory, or multiple GPUs connected with RDMA.We’re looking for a systems engineer who enjoys working deep in the stack. You’ll build production runtime infrastructure in Rust and Go, diagnose difficult Linux and performance problems, and help determine the architecture of Modal’s container platform. You’ll also work closely with maintainers of gVisor and contribute to the runtime itself when the right fix belongs upstream. The Work: Make container startup, checkpoint, and restore dramatically faster for large i