The people behind
the systems.

Information theory. The bit. Channel capacity. The proof that a digital signal can be transmitted over a noisy channel with arbitrarily small error if you stay below the channel capacity.

A 1948 paper, a single thinker, an entire field. Shannon also juggled, rode unicycles down Bell Labs hallways, and built mechanical chess-playing machines and a coin-tossing robot. Famously private, almost reclusive in his later years.

The Turing machine. Computability. The Turing test. The architectural model of the stored-program computer (ACE).

His 1936 paper "On Computable Numbers" defined what computation IS. He spent the war breaking Enigma at Bletchley. Persecuted for being gay; pardoned posthumously in 2013.

The von Neumann architecture (program and data in the same memory). Game theory. Cellular automata. Self-replicating systems.

Hungarian polymath who could compute 8-digit divisions in his head as a child. Worked on the EDVAC, the IAS machine, hydrogen bomb math, and von Neumann's ergodic theorem in the same week.

Dijkstra's algorithm (shortest path). The semaphore. Structured programming. The "GOTO considered harmful" letter.

Dutch, opinionated, and unapologetically theoretical. Wrote his EWDs (Edsger W. Dijkstra notes) by hand in numbered, dated essays — over 1300 of them.

TAOCP (still being written). Big-O notation as we use it. TeX (the typesetting system). Literate programming. MMIX. Knuth-Morris-Pratt.

Started TAOCP in 1962. Stopped using email in 1990 to "stay focused". Pays $2.56 ("hexadecimal dollar") for any error found in his books. Plays the organ.

Logical clocks. Byzantine generals. Paxos. TLA+. LaTeX (yes, that LaTeX).

Wrote the foundational papers of distributed systems while also writing the typesetting macros every academic still uses. Calls Paxos "easy" — the field disagrees.

HTTP. HTML. URIs. The first browser (WorldWideWeb on a NeXTSTEP machine). The Web itself.

A 1989 proposal at CERN, written on a NeXT cube under his desk. Refused to patent the Web. His father Conway Berners-Lee independently invented the binary search tree in 1960.

TCP/IP, with Bob Kahn. The protocols that hold the internet together.

Cerf's 1974 paper with Kahn ("A Protocol for Packet Network Intercommunication") is the founding document of the modern internet. Hearing-impaired since birth; became a tireless advocate for accessibility.

DNS. RFC 882 and RFC 883 in 1983. The hierarchical name system that replaced HOSTS.TXT.

Designed DNS to handle a network of "thousands or millions" of hosts at a time when ARPANET had ~300. The decision to push delegation to the leaves is why DNS still works at internet scale.

JavaScript. Wrote the first version in 10 days in May 1995 for Netscape. Co-founded Mozilla; later founded Brave.

JavaScript was supposed to be a "scripting language for designers" subordinate to Java. It became the most-deployed runtime on Earth.

curl and libcurl. The HTTP client running in cars, refrigerators, satellites, every Linux distro.

Started curl in 1996. Twenty-eight years of nights-and-weekends maintenance turned a personal utility into infrastructure on billions of devices. Famously responded to a corporate "we have a curl issue" email by listing the dollar amount his volunteer work was saving them.

Consistent hashing (1997 thesis with collaborators). The Akamai CDN.

Karger's consistent-hashing paper was originally about CDN load distribution. Today the same idea is in every distributed cache, KV store, and shard router.

AWK (the K). The K&R book. "The Practice of Programming". "The Go Programming Language" (with Donovan).

The clearest technical writer in the history of computing. Co-wrote books with Ritchie, Pike, Donovan, Plauger. Coined "Hello, World!" — sort of; the phrase predates him but K&R made it canonical.

Linux (1991). Git (2005, written in 10 days because BitKeeper revoked Linux's license).

Two pieces of infrastructure that hold up most of computing — both written as personal projects. Famously direct on the kernel mailing list; mellowed considerably after a 2018 self-imposed sabbatical.

The Apollo flight software. Coined the term "software engineering". Foundational work on fault-tolerance and priority scheduling — used to recover Apollo 11's landing computer when alarms went off seconds before touchdown.

Photographed standing next to a stack of Apollo source-code printouts taller than she was. The image is the most-shared piece of programming history on the internet.

A-0, the first compiler (1952). FLOW-MATIC, which became COBOL. The argument that programming languages should be human-readable.

Joined the Navy at 37, retired at 79 (the Navy kept calling her back). Carried "nanoseconds" — 11.8-inch lengths of wire — to demonstrate the distance light travels in a billionth of a second. Found the original "computer bug" — a literal moth in the Mark II.

CLU (the first language with abstract data types). The Liskov substitution principle. Distributed-systems work on Argus and Thor.

First American woman to earn a PhD in computer science (Stanford 1968). Her LSP — "if S is a subtype of T, then objects of T may be replaced with objects of S without altering correctness" — is one of the few principles every working OO programmer can name.

A library of widely-cited engineering essays — on processor design, latency, hiring, "computer latency: 1977-2017", "the empirical case against branch prediction performance papers".

A working hardware engineer who blogs at danluu.com and quietly changed how a generation of engineers think about benchmarking, hiring, and "what does the data actually say?".

Erlang and OTP (1986). The "let it crash" philosophy of fault tolerance. Process supervision trees that have run telecom switches for decades at nine-nines availability.

Designed Erlang to keep AXD301 phone switches running through hardware faults, software bugs, and live upgrades. The patterns he formalised — supervisors, GenServers, hot code reload — show up in every modern actor framework, from Akka to Elixir.

The first algorithm intended for execution on a machine — a Bernoulli-number computation for Babbage's Analytical Engine, written in 1843.

In annotated notes on a French paper about the Analytical Engine, Lovelace went well beyond the source: she described conditional branching, loops, and the machine's potential for non-numeric computation ("composing music"). The Engine was never built; her algorithm is older than electricity-powered computing by a century.

Docker (2013). Took kernel features that had existed for years (cgroups, namespaces, union mounts) and wrapped them in a Dockerfile and a CLI normal humans could use. Containerised the industry in roughly 18 months.

Demoed Docker for the first time at PyCon 2013 in a five-minute lightning talk. The talk now has its own folklore status; many engineers remember exactly where they were when they first ran "docker run". Left Docker Inc. in 2018, building Dagger now.

Kubernetes (2014). Took everything Google had learned about Borg over a decade, redesigned it to be open-source, declarative, and CRD-extensible, and gave it away. Re-shaped what "infrastructure" means at most engineering orgs.

Three engineers at Google in 2013, an internal pitch deck called "Project 7" (after Star Trek's Seven of Nine — the friendliest Borg), and a bet that the industry would eventually want this. Open-sourced 1.0 in 2015. By 2020 it was the second-largest open-source project on Earth.

Redis (2009). The argument that a single-threaded in-memory data structure server, written in C, would beat sharded clusters at most things people actually wanted from a key-value store. He was right.

Wrote Redis in his spare time to power a real-time analytics product nobody used. Open-sourced it because the analytics product wasn't working. Stepped down in 2020 to focus on writing fiction; came back to Redis in 2024 because no one else was going to keep adding the data types.

Lucene (1999, search). Nutch (2002, web crawler). Hadoop (2006, with Mike Cafarella) — an open-source clone of Google's GFS + MapReduce papers that powered a decade of "big data" infrastructure.

Read Google's 2003 GFS paper and the 2004 MapReduce paper, then proceeded to spend the next two years implementing them in his garage office, named the project after his son's stuffed elephant. The name has outlasted the technology.

MapReduce (2004), Bigtable (2006), Spanner (2012), the TPU. The pair-programming partnership that built most of Google's internal infrastructure and, by extension, the playbook for "hyperscale".

They share an office and write papers together; the joke at Google is that they share a brain. The "Jeff Dean facts" meme — "Jeff Dean compiles and runs his code before submitting, but only to check for compiler bugs" — exists because the underlying productivity is unreasonable.

Node.js (2009) — JavaScript on the server with non-blocking I/O. Deno (2018) — Node.js with all the things he wished he'd done differently the first time.

Built Node in a few months in 2009 because nginx + JavaScript should have been a thing. Stepped away in 2012, came back in 2018 with a JSConf EU talk titled "10 Things I Regret About Node.js", then shipped Deno. Rare rebooter who didn't fork his own community.

The Signal Protocol — X3DH key exchange, the Double Ratchet algorithm, sealed sender, prekey bundles. The crypto layer underneath Signal, WhatsApp, Skype, and Google Messages. End-to-end encryption for several billion humans.

Lived on a sailboat for several years while building Signal. Rejected the idea of decentralisation for messaging — wrote a viral 2022 essay arguing centralised services are the only way to ship usable crypto. Stepped down as Signal CEO in 2022 but stayed on the board.

Backpropagation in practice (Hinton, 1986). Convolutional neural networks (LeCun, 1989). Modern deep learning, AlexNet (with Krizhevsky and Sutskever, 2012), the architectures that became GPT and everything after.

Spent thirty years working on neural networks while the field considered them dead. Got the last laugh in 2012 when AlexNet won ImageNet by a margin so large the field instantly pivoted. Hinton resigned from Google in 2023 to "speak freely" about AI risk; LeCun runs Meta AI; Bengio runs Mila in Montréal.