Li, a senior data scientist at Netflix who previously worked at Spotify and DoorDash, argues that practical data science at scale rewards the unglamorous: repeatable infrastructure, interpretable forecasting models, and expertise in the manual work before any automation. He makes the same case for careers. What got him into Netflix was not a tactic but a rare combination of skills, ads plus forecasting, at the moment Netflix needed it.
Scale versus zero-to-one. The host frames Li's work as Spotify's ad business of over a hundred million dollars a year and Netflix's billion-dollar supply-and-demand forecasting. Li says zero-to-one work, like starting Spotify's podcast ads, is hacky and fast. Scale demands naming conventions, reusable frameworks, and model auditing and alerting. Li explains that Spotify bought Megaphone, alongside big exclusive deals and Anchor for small creators, to own the whole podcast value chain.
Forecasting basics and pitfalls. Li describes most time-series models as linear regression adapted for autocorrelation: ARMA, exponential smoothing, and Prophet, which decomposes a series into trend, seasonality and error. The technical rookie error is a random train-test split. He uses expanding-window or sliding-window cross-validation instead. The bigger pitfall is reaching for LSTMs and transformers when stakeholders need to know why a forecast says what it does. The host says that in his 2016–2019 deep learning courses, finance students never beat simple statistical methods with deep nets. Li says the M forecasting competitions were long won by univariate methods, and that hybrid ensembles of tree-based, deep learning and univariate models now perform best. The edge from complex models may matter to a quant chasing 1.1% more accuracy, he adds, but rarely at work.
Foundation models. His team tested time-series foundation models including Chronos and TimesFM, and none beat its simple approaches. He would switch for significantly better accuracy and a business case, but explainability remains a barrier. He splits forecasting into operational uses, where accuracy rules and deep learning can fit, and strategic uses such as FP&A, where assumptions must be visible. He credits this split to a forecasting course he took.
Getting hired. The briefcase technique, a detailed pain-points doc for the hiring manager, got him into DoorDash. The host worries that such docs now look like AI spam, citing the 30-page outreach PDFs he receives weekly. Li answers that genuine specificity still lands. Netflix rejected him multiple times before its new ads business needed his ads-plus-forecasting mix. His advice is to persist and to build a niche at an overlap of skills.
Dating and AI. His former startup yourmove.ai, which the host says has over 10,000 users, began in the GPT-2 era. It grew from Li's 2019 model that auto-swiped profiles based on his own swipes. He says its suggestions helped but couldn't be fully automated, and that AI-generated photos still read as fake and count against you. He sees a shift toward in-person meeting and notes he met his girlfriend through skiing; she filtered dating apps for men 6 feet and over, and he is 5'9". The host relays news that Match Group's share price fell as post-pandemic dating-app activity dropped, with apps betting on AI.
Automation and agents. His failed ad-creative automation taught him to master a workflow manually first. He says he spent about $200 of API credits learning to prompt image models. He softens his "agents are just Python scripts" tweet: let the LLM decide whether to trigger, and keep execution deterministic.
Tools and mental models. AI has made him favour monorepos, because coding agents find context in one place more easily. His stack at the time of recording: Wispr Flow for dictating rich prompts (he writes specs by hand to think them through), Claude Code, Cursor's new Composer 1 model, Gemini's Nano Banana for images that keep his face intact, and v0 for front ends. He says the best tool for a job changes "week to week". He borrows mental models from Charlie Munger, including asymmetric upside, such as going to parties with interesting people, and activation energy.