light table

Matt Kulukundis explains how Google designed SwissTable, a fast, cache-friendly hash table, step by step from std::unordered_map. The talk covers open addressing, SIMD probing and the tradeoffs of changing a fundamental data structure.

Lee Byron of Facebook explains how persistent immutable data structures work and how to use them in React apps with Immutable.js. He covers memoization benefits and avoiding coupling through shared mutable state.

Matt Kulukundis reviews two years of Abseil's Swiss table hashtable, covering post-release optimizations, lessons from rolling it out across Google, design choices, and what global monitoring revealed.

Malte Skarupke's C++Now 2018 talk on hash table performance, explaining why std::unordered_map is slow and memory hungry and presenting faster designs, including his bytell hash map.

Juan Pedro Bolivar Puente explains immutable and persistent data structures in C++ and how they support value semantics. He presents the Immer library, rrb-trees, and a prototype text editor that opens a huge file instantly.

A PyCon 2013 block of Friday evening lightning talks. It includes the debut of Hy, a Lisp dialect that compiles to Python AST, and Solomon Hykes's first public talk on Docker.

A 2007 Google Tech Talk in which Cliff Click of Azul Systems presents a lock-free concurrent hash table that scales to 768 CPUs. He explains why it is correct by reasoning in a different way than usual happens-before and memory-order arguments.

JPL's David Cummings presents at the 2025 Flight Software Workshop how the team diagnosed and fixed the 2023 Voyager 1 anomaly from billions of miles away. It walks through the flight computer and the memory fix.

Tom7 explains how he built a SIGBOVIK 2017 paper made only of printable ASCII bytes that is also a valid DOS executable. He writes a C compiler targeting printable x86 without self-modifying code and solves the puzzles the constraint creates.

Nina Teicholz, author of The Big Fat Surprise, speaks at Low Carb Gold Coast 2017 about the history and health implications of vegetable and seed oils. She covers the political and institutional forces behind dietary fat advice.

A Ropecon 2019 talk by a lighting designer and a software engineer on how the Odysseus larp spaceship was built, using over ten IT systems, hundreds of lights and dozens of speakers. It covers the lessons learned.

A five-minute lightning talk from React.js Conf 2016 by Elie Rotenberg on protecting the DOM from tampering. It shows how React tree obfuscation (react-armor) can shuffle class names, tags and tree structure to defeat CSS-selector-based ad blocking.

Justine Tunney presents Redbean, a web server distributed as a single actually portable executable that runs on multiple operating systems. It embeds Lua, SQLite and MbedTLS in a fork-based server.

A collection of lightning talks from the Surge 2015 conference on scalable systems, hosted by Geir Magnusson. HN mostly points to one segment, a Bryan Cantrill talk touching on madvise semantics.

David Nolen reviews the first five years of ClojureScript, documenting its landmarks and looking ahead to the next five. It is a history-and-roadmap talk from the Clojure community.

Timothy Baldridge presents Pixie, a lightweight Lisp built on RPython, at Strange Loop 2015. It covers C interop, immutable data structures, fast startup and async-by-default IO.

Inventor Mary Lou Jepsen demonstrates using red light and sound to see inside the body and brain, aiming at tumor detection and neural activity measurement, and potentially a cheaper wearable MRI replacement.

A Google Tech Talk by the author of Kilim, a Java library for lightweight actor-style message passing. It argues that message passing can replace shared-memory concurrency and claims performance competitive with or better than Erlang for huge numbers of actors.

Ted Young of LightStep proposes trace testing, using distributed tracing data to unify testing and observability. The KubeCon-era talk argues for testing against trace data rather than treating tests and monitoring separately.

Richard Feldman's elm-conf talk on designing models so that bugs from impossible application states cannot occur, using Elm's compiler and types. It demonstrates techniques for making invalid states unrepresentable.

Rich Hickey's JaxConf 2012 keynote examines what values are and why immutable values matter as information systems grow more complex and data gets bigger. It contrasts places with values and builds the case for immutability.

Martin Kleppmann argues that databases are global shared mutable state and proposes treating them as an ever-growing log of immutable facts. Derived data such as caches, indexes and views is then built by stream processors like Apache Samza. The talk draws on Kafka and LinkedIn's experience with commit logs.

Python core developer Raymond Hettinger explains how Python's dictionary implementation evolved into the compact, ordered dict in Python 3.6. He uses pictures and small bits of pure Python, and covers key-sharing, compaction and versioning.

Cardiologist James O'Keefe argues in a TEDx talk that moderate running confers the best longevity benefits, while extreme endurance training can damage the heart. He draws on data and his own experience as a lifelong runner.

David Nolen presents Om Next, the redesign of the ClojureScript Om library, drawing on Relay, Netflix's JSONGraph and Datomic. He covers the tradeoffs in handling the client-server boundary over immutable data.

Bruce Waggoner of the Voyager team describes how engineers diagnosed Voyager 1's 2023 loss of telemetry and patched its flight software from 15 billion miles away. The talk covers the spacecraft's architecture and the scarcity of old documentation.

Bobby Powers presents Mesh, a drop-in malloc replacement that eliminates memory fragmentation in unmodified C/C++ programs by compacting memory. The talk covers how it works despite C's fixed object addresses, and its benefits for programs like Redis.

Aaron Hsu shows how to manipulate and transform tree data in APL using arrays and inverted tables instead of pointers. He claims much smaller code, better performance and easier parallelisation.

An excerpt from an RSA event in which physicist David Deutsch makes the case for optimism as a driver of progress in the 21st century. It is a short highlight of a longer discussion.

Go runtime contributor Dmitry Vyukov looks inside the Go scheduler, explaining how goroutines and channels are implemented. He covers the main scheduler components and overall operation, then goes into details such as preemption and stacks.

Paul Irish's Chrome Dev Summit 2016 talk surveys the state of the art in Chrome DevTools debugging. It covers workspaces, diffs, CSS coverage, Node debugging, editor improvements and Lighthouse.

Max Brunsfeld of GitHub presents Tree-sitter, a parsing system for programming tools that supports incremental, error-tolerant parsing. He demos its integration into GitHub.com and Atom for syntax highlighting and code navigation.

Ramesh Raskar presents femto-photography, a technique that captures a trillion frames per second, fast enough to show light itself moving through a scene. He discusses possible uses such as cameras that see around corners or inside the body.

Rick Houlihan's AWS re:Invent 2018 deep dive on advanced DynamoDB design patterns. It covers index overloading, GSI sharding, composite keys, graph processing and transactions.

Destin Sandlin of Smarter Every Day gives a talk to an aerospace audience, comparing how Apollo was engineered and managed with NASA's Artemis program. He raises concerns about unresolved details, the number of launches and in-orbit fuel transfer needed to reach the Moon, and the loss of institutional knowledge.

Scott Wlaschin's NDC talk on using statically typed functional programming, F# in particular, to model a business domain. Types are used to represent the domain precisely and to encode business rules so that illegal states cannot be built, with the compiler acting as an instant unit test.

Richard Feldman explains how pure functional languages can match or beat imperative ones on performance. Compilers can turn immutable code into in-place mutation, avoiding naive copying. The talk draws on his work on the Roc language.

Rich Hickey's talk on time, state, identity and values, arguing that mutable object-oriented modeling fits the world poorly. It lays out the thinking behind Clojure's approach to data and change.

Rich Hickey, creator of Clojure and designer of Datomic, gives a JaxConf 2012 talk that takes apart traditional database architecture. He presents a different way to think about databases and explains the reasoning behind Datomic's fact-based design.

An AWS re:Invent 2019 session for advanced DynamoDB users on design patterns used by large customers, including Amazon retail. It covers GSI sharding, index overloading, graph processing, composite keys and transactional workflows.