Senior Software Engineer, Machine Learning Infrastructure - Generative AI

Job description

<div class="content-intro"><p><img style="display: none; max-width: 100%;" src="https://click.appcast.io/greenhouse-te8/a31.png?ent=34&amp;e=22630&amp;t=1701374353806" width="1px"> <img style="display: none; max-width: 100%;" src="https://track.jobadx.com/v1/i.gif?utm_pixel=224e990b-8ff4-4287-8d5d-2ff09647f181&amp;utm_ptz=EST&amp;utm_rqt=track" alt="" width="1"></p></div><h2><strong>About the Team</strong></h2> <p>DoorDash’s GenAI Platform team sits within Machine Learning Platform and builds the shared infrastructure that helps DoorDash, Wolt, and Deliveroo teams safely bring GenAI-powered products, agents, automation, and personalization to production. Our mission is to increase the velocity of business impact from GenAI. A central pillar of that work is running frontier open-weight LLMs and VLMs (such as GLM, Qwen, Kimi, and DeepSeek) ourselves — real-time GPU serving, high-throughput batch inference, and fine-tuning on autoscaling GPUs — delivering large cost and latency wins (for example, a billion embeddings produced roughly 20× cheaper and visual models served roughly 72% cheaper). We also own core platform surfaces including the LLM Gateway, Agent Gateway, evals infrastructure, guardrails, and cost attribution.</p> <h2><strong>About the Role</strong></h2> <p>You will join a small, high-leverage team building production infrastructure for Generative AI at DoorDash, leading the design and architecture of our open-weights model platform spanning inference and fine-tuning: real-time GPU serving, high-throughput batch inference, and model fine-tuning. You’ll set technical direction across model serving and inference engines, fine-tuning and training pipelines, GPU autoscaling and utilization, batch pipelines, backend services, and observability, and mentor engineers as you go. This role is ideal for a senior engineer who enjoys owning ambiguous, high-impact systems and pushing the cost/performance frontier of GPU inference and fine-tuning in a fast-moving technical area where product needs, model capabilities, vendor ecosystems, and cost/performance tradeoffs are evolving quickly.</p> <h2><strong>You’re excited about this opportunity because you will…</strong></h2> <ul> <li>Lead the design of infrastructure that helps DoorDash teams move GenAI ideas from prototype to production, increasing the velocity of business impact from AI across the company.</li> <li>Own and evolve our open-weights serving stack — real-time GPU endpoints, high-throughput batch inference, and fine-tuning (SFT/DPO/LoRA) — alongside the LLM Gateway, Agent Gateway, evals infrastructure, guardrails, and cost attribution.</li> <li>Architect scalable, high-performance systems for model serving, batch inference, GPU autoscaling, and fine-tuning that power real customer and internal automation use cases</li> <li>Push the cost and latency frontier of GPU inference — turning batch jobs that took days into hours and cutting inference cost by multiples — while giving product teams a clean choice across open-weight and closed-source models with reliability, fallback, observability, and cost controls built in.</li> <li>Build platforms that support rapid experimentation while meeting production standards for latency, scale, monitoring, SLOs, playbooks, and operational excellence.</li> <li>Partner closely with — and raise the technical bar for — ML engineers, product engineers, data scientists, and platform teams across DoorDash, Wolt, and Deliveroo to turn emerging GenAI capabilities into durable platform primitives.</li> <li>Set technical direction for the future of DoorDash’s centralized GenAI platform — including emerging directions such as reinforcement learning (RLHF/RLVR), agent optimization, and other post-training and agentic techniques — enabling the next generation of AI-powered products, agents, automation, and personalization.</li> </ul> <h2><strong>We’re excited about you because…</strong></h2> <ul> <li>B.S., M.S., or PhD. in Computer Science or equivalent</li> <li>6+ years of industry experience in software engineering</li> <li>Deep backend engineering fundamentals, especially in Python and distributed systems.</li> <li>Track record of designing and owning production services, APIs, data pipelines, or ML infrastructure at scale.</li> <li>Experience operating systems in production, including observability, debugging, reliability, incident response, and performance/cost optimization.</li> <li>Deep hands-on experience with LLM inference and/or fine-tuning of open-weight models in production — serving (latency, throughput, batching, autoscaling, GPU utilization) and/or fine-tuning (SFT/DPO/LoRA).</li> <li>Demonstrated technical leadership: leading design across ambiguous, fast-moving technical areas, mentoring engineers, and turning customer use cases into reusable platform capabilities</li> <li>Proficiency in using AI coding tools (e.g., Claude Code, Codex, Cursor) in the full software development lifecycle, including designing, generating code, testing, monitoring and releasing software</li> </ul> <h3><strong>Nice To Haves</strong></h3> <ul> <li>Experience with LLM inference engines and serving frameworks (e.g., vLLM, SGLang, TensorRT-LLM) in production</li> <li>Experience with distributed/multi-node fine-tuning and training pipelines (SFT, DPO/RLHF, LoRA), including data preparation and evaluation</li> <li>GPU performance work — multi-node/distributed inference, KV-cache/memory optimization, quantization (FP8/INT8/AWQ/GPTQ), or cold-start/throughput tuning</li> <li>Experience with Kubernetes, cloud infrastructure (AWS/GCP), GPUs, serverless/elastic GPU platforms (e.g., Modal), or high-throughput batch systems</li> <li>Experience with LLM gateways, model routing, vendor abstraction, or cost attribution</li> <li>Experience building developer platforms, internal platforms, or self-serve infrastructure</li> <li>Experience building and deploying AI agents or MCP servers in production</li> <li>Experience with eval systems, LLM observability, tracing, RAG, search, or vector databases</li> </ul> <p>&nbsp;</p> <p data-renderer-start-pos="553"><strong data-renderer-mark="true">Notice Regarding Use of AI and Automated Tools:&nbsp;</strong>To streamline our hiring process, DoorDash utilizes an automated recruitment tool called Gem.</p> <p data-renderer-start-pos="696"><strong data-renderer-mark="true">How it works: </strong>Gem assists our recruiting team by evaluating job related qualifications and characteristics in connection with hiring. The tool is designed and used to support - rather than replace - human decision-making; trained personnel make final decisions with meaningful human review and oversight, and DoorDash does not use Gem or other AI-enabled tool&nbsp; in a manner that has the effect of subjecting applicants or employees to discrimination based on any protected characteristic or proxy or for engaging in any protected activity under applicable law.</p> <p data-renderer-start-pos="1257"><strong data-renderer-mark="true">Data Retention, Privacy &amp; Bias Audit:</strong> Data collected during this process is retained in accordance with our <a class="_ymio1r31 _ypr0glyw _zcxs1o36 _mizu194a _1ah3dkaa _ra3xnqa1 _128mdkaa _1cvmnqa1 _4davt94y _4bfu18uv _1hms8stv _ajmmnqa1 _vchhusvi _kqswh2mm _ect4ttxp _2rkolb4i _syaz13af _1a3b18uv _4fpr8stv _5goinqa1 _f8pj13af _9oik18uv _1bnxglyw _jf4cnqa1 _30l313af _1nrm18uv _c2waglyw _1iohnqa1 _9h8h12zz _10531ra0 _1ien1ra0 _n0fx1ra0 _1vhv17z1" href="https://help.doordash.com/en-us/legal/article/ax-privacy-notice" data-renderer-mark="true" data-is-router-link="false" data-testid="link-with-safety"><u data-renderer-mark="true">Candidate Privacy Policy</u></a> and applicable state laws. In compliance with New York City Local Law 144, the independent bias audit summary for Gem is publicly available for review at our <a class="_ymio1r31 _ypr0glyw _zcxs1o36 _mizu194a _1ah3dkaa _ra3xnqa1 _128mdkaa _1cvmnqa1 _4davt94y _4bfu18uv _1hms8stv _ajmmnqa1 _vchhusvi _kqswh2mm _ect4ttxp _2rkolb4i _syaz13af _1a3b18uv _4fpr8stv _5goinqa1 _f8pj13af _9oik18uv _1bnxglyw _jf4cnqa1 _30l313af _1nrm18uv _c2waglyw _1iohnqa1 _9h8h12zz _10531ra0 _1ien1ra0 _n0fx1ra0 _1vhv17z1" href="https://careersatdoordash.com/wp-content/uploads/2026/06/Gem-BABL-Bias-Audit-Results-2-1.pdf" data-renderer-mark="true" data-is-router-link="false" data-testid="link-with-safety"><u data-renderer-mark="true">Careers Page</u></a>.&nbsp;</p><div class="content-pay-transparency"><div class="pay-input"><div class="description"><p><span style="font-size: 32px;"><strong>Compensation<br></strong></span></p> <p>The successful candidate's starting pay will fall within the pay range listed below and is determined based on job-related factors including, but not limited to, skills, experience, qualifications, work location, and market conditions.&nbsp; Base salary is localized according to an employee’s work location. Ranges are market-dependent and may be modified in the future.</p> <p>In addition to base salary, the compensation for this role includes opportunities for equity grants. Talk to your recruiter for more information.</p> <p>DoorDash cares about you and your overall well-being. That’s why we offer a comprehensive benefits package to all regular employees, which includes a 401(k) plan with employer matching, 16 weeks of paid parental leave, wellness benefits, commuter benefits match, paid time off and paid sick leave in compliance with applicable laws (e.g. Colorado Healthy Families and Workplaces Act). DoorDash also offers medical, dental, and vision benefits, 11 paid holidays, disability and basic life insurance, family-forming assistance, and a mental health program, among others.</p> <p>To learn more about our benefits, visit our careers page <a href="https://careers.doordash.com/">here</a>.</p> <p>See below for paid time off details:</p> <ul> <li><strong>For salaried roles:</strong> flexible paid time off/vacation, plus 80 hours of paid sick time per