YC W’21 founder of Chorus Sleep; built and led the technology org from zero to acquisition by Sleep Reset (2026)
20 years in industry, 14 leading engineering — hiring, mentoring, and growing managers and senior/principal talent
Architected and built Luna, a memory-informed agentic AI sleep coach with novel prompt + eval pipelines
Transformed engineering, product, and operations into AI-first orgs — agentic coding, extensive automation, and rigorous evals
Latest resume/cv #
A two-page resume with the full rundown of roles, impact, and technologies — available as HTML or PDF for a printable version.
Warren Runk
Engineering Leader
Something lighter #
Weew, sorry for the corp-speak
I'm also a normal human being just trying to raise great kids, have fun at work, and enjoy a lot of hockey. Also, I have become quite obsessed with Claude Code!
I have a deep curiosity and (sometimes annoying) predilection toward rabbit hole diving, and this has only become worse with LLMs and their endless provisioning of said holes. Audiobooks, wikipedia, hackernews, regular books, and ClaudeResearch really aren’t helping this problem at all
Apologies, but back to the formal stuff:
Experience #
- Co-Founded and led Chorus Sleep (YC W’21) from zero to acquisition by Sleep Reset (May 2026). Backed by Y Combinator, Precursor Ventures, and Goat Capital.
- Grew Chorus to 100k+ paid users across 26 countries, with 80% month-1 / 50–60% month-6 cohort retention, and clinically meaningful outcomes – 30% faster sleep onset, 30% fewer awakenings, 20% better daytime functioning.
- Architected and built Luna, a memory-informed agentic AI sleep coach – real-time conversational reasoning, novel prompt + eval pipelines that operate safely over personal health and behavior data, and personalized, multi-step interventions tuned to each user.
- Transformed engineering, product, and operations into AI-first orgs starting in late 2022 – agentic coding (~90% AI-written code under rigorous evals), agent-driven content + ops workflows, and automation replacing hand-written code and manual processes; created ~5 FTEs of equivalent capacity on a lean team.
- Shipped at AI-leveraged startup velocity – full platform internationalization across mobile, web, and content library in 6 weeks (12 languages) for a major B2B partner; near-fully-automated audio, written, and image content pipelines.
- Product-obsessed, customer-first – weekly mom-test style calls with users, deep analytics + A/B experimentation, and white-glove B2B onboarding designed to scale without ballooning team workload.
- Co-led B2B sales and the full M&A process through acquisition. Comfortable across the table from C-suites, boards, investors, and high-net-worth individuals; ran dozens of such conversations with calm, professional partnership.
- Operated as a true business co-owner – co-led capital planning, P&L, fundraising, vendor/partner contracts, and the cross-functional decisions (HR, legal, ops) typically out-of-scope for leaders at larger companies.
- Built and led engineering from zero – hired, mentored, and leveled up engineers across backend (Go, Postgres), native mobile (Swift, Flutter, React Native), web, and ML; personally architect and scale the end-to-end cloud-native platform.
- Led an engineering team across backend, frontend, product/eng leads, and QA for an online publication serving millions of monthly customers – hired and developed engineers across all levels; team described by the COO as "the most effective engineering team I’ve ever seen."
- Owned and architected the AWS-to-Google-Cloud re-platform (Go, Postgres, App Engine) – eliminated entire classes of infra complexity, cut hosting cost by over 50%, and unlocked materially faster product iteration.
- Rebuilt the core CMS backend from PHP/Laravel to Go, used daily by hundreds of editorial staff – ~90% hosting cost reduction, eliminated all lost-work scenarios, and replaced a 12+ hour, nightly, fully-static publish pipeline with delta-based, CDN-backed publishes under strict verification.
- Led design and build of a novel multi-retailer shopping app with same-day, automated courier delivery – full transactional backend (users, carts, orders, messaging), ingestion of hundreds of thousands of product webpages daily, and single-checkout integrations across retailers.
- Deep cross-functional partner across product, editorial, social, D2C, marketing, HR/ops, data science, and exec leadership – drove the affiliate program rebuild using ML product classification and personalization, content syndication to Google/Apple News, third-party platform integrations, and supported the company’s sale and asset transition to Dotdash.
- Co-architected the API services, security infrastructure, and engineering roadmap from day one at a fintech startup building frictionless in-store and online checkout – Go, AWS, Postgres; the underlying technology generated multiple US patents for the company.
- Built, mentored, and led engineering team across backend, iOS, Android, frontend, ops, and contractors.
- Partnered with the CEO on enterprise sales, translating complex technical material for executive audiences and helping negotiate and close Toyota Financial and other strategic accounts.
- Owned and led "The Great Migration" – ported 3+ billion records of core site data from a ~15-year-old Oracle/Java platform onto Google Cloud; affected and enhanced service for ~300M+ registered users, millions of invitations per year – the de facto digital invitation platform of the era.
- Promoted 3 times across 4.5 years from software engineer to Director of Engineering – co-led entire engineering org; hired, mentored, and grew engineers across frontend, backend, DevOps, and QA; ran performance reviews, retention, technical growth, and leadership training and opportunity.
- Designed and built REST APIs, internal tools, and data pipelines serving five+ client applications across web, native mobile, and partner integrations – high-volume, on-prem infrastructure handling heavy event/holiday traffic spikes.
- Operated and scaled core on-prem distributed systems – an SRE-like role spanning MySQL clusters, Memcached, NoSQL stores, heavy background task/queue processing, and personally built zero-downtime deployment, provisioning, and traffic-splitting tooling.
- Built backend services and webapps in C++, Python, and Perl for a large-scale, pre-cloud MMO virtual world (There.com, VirtualMTV) – thousands of on-prem Linux servers (~300 per cluster).
- Foundational experience in large distributed systems, production Linux ops, and large MySQL clusters – all self-managed infrastructure with no cloud services to fall back on.
- Shipped into 20+ live production releases against a 7M+ line codebase – learned disciplined release engineering, code review, and structured QA at industrial scale early in career.
Education #
Y Combinator – Elite startup accelerator and investor; Batch Winter 2021.
University of California, Riverside (2006) – B.S. Computer Science.