Signals and Threads

Jane Street

Listen in on Jane Street’s Ron Minsky as he has conversations with engineers who are working on everything from clock synchronization to reliable multicast, build systems to reconfigurable hardware. Get a peek at how Jane Street approaches problems, and how those ideas relate to tech more broadly. You can find transcripts along with related links on our website at signalsandthreads.com. read less

Our Editor's Take

Signals and Threads is for people working in computer science and software engineering. The podcast explains concepts and technologies used by trading companies, such as Jane Street. It talks about crucial topics in the field, like FPGA design and dependent types. Host Ron Minsky makes sure the information is simple and accessible. This makes the podcast useful for any software developer, even outside financial technologies.

The host of Signals and Threads has been with Jane Street for over two decades. Minsky joined the company in 2003, doing quantitative trading. During his career, the host led some of the most critical advancements in the firm. He was the one to establish a quantitative research group. Later, he facilitated the company's transition to OCaml.

Outside his work with Jane Street, Minsky also writes about programming. He creates tutorials and real-world examples for OCaml uses. Some of his articles appeared in notable publications, like the Journal of Functional Programming. Minsky's vast experience helps him ask the right questions on the podcast, which leads to compelling discussions.

Signals and Threads conducts conversations about every layer of the tech stack. The podcast host interviews hardware designers, software engineers, coders, and developers. They examine topics such as programmable hardware and compiler optimization. There are conversations about the difference between Python and OCaml in machine learning. Other discussions deal with language design, and how it's as much an art as it is a science.

All of the guests on Signals and Threads are Jane Street employees. As they discuss the work they do, they also reveal more about the firm and how it operates. However, the interviewees also share their experiences from other fields. They talk about their academic research and computing problems relevant to the industry.

Signals and Threads is a well-researched and well-produced podcast. The discussions are precise, ensuring that they stay on topic without any tangents. It's a great educational tool for anyone in financial technologies and beyond.

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More Signals & Threads coming soon!

More Signals & Threads coming soon!

Signals & Threads is back, and we have a fun season of topics lined up, including: Building better abstractions for design and user interfaces, the role of writing in a technical organization, the approach that different languages take to memory management...and more. We hope you’ll join us. The first episode drops September 1st.

Episodes

Solving Puzzles in Production with Liora Friedberg

Solving Puzzles in Production with Liora Friedberg

Liora Friedberg is a Production Engineer at Jane Street with a background in economics and computer science. In this episode, Liora and Ron discuss how production engineering blends high-stakes puzzle solving with thoughtful software engineering, as the people doing support build tools to make that support less necessary. They also discuss how Jane Street uses both tabletop simulation and hands-on exercises to train Production Engineers; what skills effective Production Engineers have in common; and how to create a culture where people aren’t blamed for making costly mistakes.You can find the transcript for this episode on our website.Some links to topics that came up in the discussion:More about production engineering at Jane Street, including how to apply.Notes on Site reliability engineering in the wider world.Alarm fatigue and desensitization.Jane Street’s 1950’s era serialization-format of choice,Some games that Streeters have used for training people to respond to incidents.

From the Lab to the Trading Floor with Erin Murphy

From the Lab to the Trading Floor with Erin Murphy

Erin Murphy is Jane Street’s first UX designer, and before that, she worked at NASA’s Jet Propulsion Laboratory building user interfaces for space missions. She’s also an illustrator with her own quarterly journal. In this episode, Erin and Ron discuss the challenge of doing user-centered design in an organization where experts are used to building tools for themselves. How do you bring a command-line interface to the web without making it worse for power users? They also discuss how beauty in design is more about utility than aesthetics; what Jane Street looks for in UX candidates; and how to help engineers discover what their users really want.You can find the transcript for this episode on our website.Some links to topics that came up in the discussion:Erin’s website that shows off her work.Her quarterly journal of sketches and observations.An article about Erin’s design work with NASA JPL.A paper that among other things talks about the user study work that Erin did at JPL.Jane Street’s current UX job opening.

Performance Engineering on Hard Mode with Andrew Hunter

Performance Engineering on Hard Mode with Andrew Hunter

Andrew Hunter makes code really, really fast. Before joining Jane Street, he worked for seven years at Google on multithreaded architecture, and was a tech lead for tcmalloc, Google’s world-class scalable malloc implementation. In this episode, Andrew and Ron discuss how, paradoxically, it can be easier to optimize systems at hyperscale because of the impact that even miniscule changes can have. Finding performance wins in trading systems—which operate at a smaller scale, but which have bursty, low-latency workloads—is often trickier. Andrew explains how he approaches the problem, including his favorite profiling techniques and tools for visualizing traces; the unique challenges of optimizing OCaml versus C++; and when you should and shouldn’t care about nanoseconds. They also touch on the joys of musical theater, and how to pass an interview when you’re sleep-deprived.You can find the transcript for this episode on our website.Some links to topics that came up in the discussion:“Profiling a warehouse-scale computer”Magic-traceOODA loop

A Poet's Guide to Product Management with Peter Bogart-Johnson

A Poet's Guide to Product Management with Peter Bogart-Johnson

Peter Bogart-Johnson was one of Jane Street’s first program managers, and helped bring the art of PMing—where that “P” variously stands for “project,” “product,” or some blend of the two—to the company at large. He’s also a poet and the editor of a literary magazine. In this episode, Peter and Ron discuss the challenge of gaining trust as an outsider: how do you teach teams a new way of doing things while preserving what’s already working? The key, Peter says, is you listen; a good PM is an anthropologist. They also discuss how paying down technical debt isn’t something you do instead of serving customers; what Jane Street looks for in PM candidates; and how to help teams coordinate in times of great change.You can find the transcript for this episode on our website.Some links to topics that came up in the discussion:LIT Magazine (more recently here)How to be a PM that engineers don’t hate and How to be an engineer that PMs don’t hate

The Future of Programming with Richard Eisenberg

The Future of Programming with Richard Eisenberg

Richard Eisenberg is one of the core maintainers of Haskell. He recently joined Jane Street’s Tools and Compilers team, where he hacks on the OCaml compiler. He and Ron discuss the powerful language feature that got him into PL design in the first place—dependent types—and its role in a world where AIs can (somewhat) competently write your code for you. They also discuss the differences between Haskell and OCaml; the perils of trying to make a language that works for everybody; and how best a company like Jane Street can collaborate with the open source community.You can find the transcript for this episode on our website.Some links to topics that came up in the discussion:Dependent typesGHCUnboxed types in OCamlLanguage extensions in Haskell

Swapping the Engine Out of a Moving Race Car with Ella Ehrlich

Swapping the Engine Out of a Moving Race Car with Ella Ehrlich

Ella Ehrlich has been a developer at Jane Street for close to a decade. During much of that time, she’s worked on Gord, one of Jane Street’s oldest and most critical systems, which is responsible for normalizing and distributing the firm’s trading data. Ella and Ron talk about how to grow and modernize a legacy system without compromising uptime, why game developers are the “musicians of software,” and some of the work Jane Street has done to try to hire a more diverse set of software engineers.You can find the transcript for this episode on our website.Some links to topics that came up in the discussion:EG, The League of Legends team that Ella is a huge fan of.Apache Kafka, the message bus that Gord migrated to.Some of the various sources of symbology you have to deal with when normalizing trading data. (Really, there are too many sources to list here!)A list of Jane Street’s recruiting Programs and Events, including INSIGHT, which focuses on women, and IN FOCUS, which focuses on historically underrepresented ethnic or racial minorities.

State Machine Replication, and Why You Should Care with Doug Patti

State Machine Replication, and Why You Should Care with Doug Patti

Doug Patti is a developer in Jane Street’s Client-Facing Tech team, where he works on a system called Concord that undergirds Jane Street’s client offerings. In this episode, Doug and Ron discuss how Concord, which has state-machine replication as its core abstraction, helps Jane Street achieve the reliability, scalability, and speed that the client business demands. They’ll also discuss Doug’s involvement in building a successor system called Aria, which is designed to deliver those same benefits to a much wider audience.You can find the transcript for this episode on our website.Some links to topics that came up in the discussion:Jane Street’s client-facing trading platformsA Signals and Threads episode on market data and multicast which discusses some of the history of state-machine replication in the markets.The FIX protocolUDP multicastReliable multicastKafka

Memory Management with Stephen Dolan

Memory Management with Stephen Dolan

Stephen Dolan works on Jane Street’s Tools and Compilers team where he focuses on the OCaml compiler. In this episode, Stephen and Ron take a trip down memory lane, discussing how to manage computer memory efficiently and safely. They consider trade-offs between reference counting and garbage collection, the surprising gains achieved by prefetching, and how new language features like local allocation and unboxed types could give OCaml users more control over their memory.You can find the transcript for this episode on our website.Some links to topics that came up in the discussion:Stephen’s command-line JSON processor, jqStephen’s Cambridge dissertation, “Algebraic Subtyping”, and a protoype implementation of mlsub, a language based on those ideas.A post from Stephen on how to benchmark different memory allocators.A Jane Street tech talk on “Unboxed Types for OCaml”, and an RFC in the OCaml RFC repo.A paper from Stephen and KC Sivaramakrishnan called “Bounding Data Races in Space and Time”, which is all about a new and better memory model for Multicore OCaml.Another paper describing the design of OCaml’s multicore GC.The Rust RFC for Higher-ranked trait bounds.

What Is an Operating System? with Anil Madhavapeddy

What Is an Operating System? with Anil Madhavapeddy

Anil Madhavapeddy is an academic, author, engineer, entrepreneur, and OCaml aficionado. In this episode, Anil and Ron consider the evolving role of operating systems, security on the internet, and the pending arrival (at last!) of OCaml 5.0. They also discuss using Raspberry Pis to fight climate change; the programming inspiration found in British pubs and on Moroccan beaches; and the time Anil went to a party, got drunk, and woke up with a job working on the Mars Polar Lander.You can find the transcript for this episode on our website.Some links to topics that came up in the discussion:Ron, Anil, and Jason Hickey’s book, “Real World OCaml”Anil’s personal website and Google Scholar pageThe MirageOS library operating systemCambridge University’s OCaml LabsNASA’s Mars Polar LanderThe Xen Project, home to the hypervisorThe Tezos proof-of-stake blockchainThe Coq Proof Assistant system

Building a UI Framework with Ty Overby

Building a UI Framework with Ty Overby

Ty Overby is a programmer in Jane Street’s web platform group where he works on Bonsai, our OCaml library for building interactive browser-based UI. In this episode, Ty and Ron consider the functional approach to building user interfaces. They also discuss Ty’s programming roots in Neopets, what development features they crave on the web, the unfairly maligned CSS, and why Excel is “arguably the greatest programming language ever developed.”You can find the transcript for this episode on our website.Some links to topics that came up in the discussion:Jane Street’s Bonsai libraryThe 3D design system OpenSCADMatt Keeter’s libfive design toolsTry .NET in-browser replJane Street’s Incr_dom libraryThe Elm Architecture “pattern for architecting interactive programs”React JavaScript libraryThe Houdini proposalSvelte UI toolkit

Writing, Technically with James Somers

Writing, Technically with James Somers

James Somers is Jane Street’s writer-in-residence, splitting his time between English and OCaml, and helping to push forward all sorts of efforts around knowledge-sharing at Jane Street. In this episode, James and Ron talk about the role of technical writing in an organization like Jane Street, and how engineering software relates to editing prose.You can find the transcript for this episode on our website.Some links to topics that came up in the discussion:mdx, the modified Markdown format that supports executing OCaml code blocksMore on the 4 types of technical writing that James referencesDonald Knuth’s original book on Literate ProgrammingMore on John McPhee’s use of KEDITPeter Seibel’s Coders at WorkDavid Goodsell’s The Machinery of LifeScott Huler’s Defining the WindSome of James’s writing on our tech blog

More Signals & Threads coming soon!

More Signals & Threads coming soon!

Signals & Threads is back, and we have a fun season of topics lined up, including: Building better abstractions for design and user interfaces, the role of writing in a technical organization, the approach that different languages take to memory management...and more. We hope you’ll join us. The first episode drops September 1st.

An inside look at Jane Street's tech internship with Jeanne Van Briesen, Matt Else, and Grace Zhang

An inside look at Jane Street's tech internship with Jeanne Van Briesen, Matt Else, and Grace Zhang

In this week's episode, the season 1 finale, Ron speaks with Jeanne, Matt, and Grace, three former tech interns at Jane Street who have returned as full-timers. They talk about the experience of being an intern at Jane Street, the types of projects that interns work on, and how they've found the transition to full-time work.You can find the transcript for this episode along with links to things we discussed on our website.

Building a functional email server with Dominick LoBraico

Building a functional email server with Dominick LoBraico

Despite a steady trickle of newcomers, email still reigns supreme as the chief communication mechanism for the Information Age. At Jane Street, it’s just as critical as anywhere, but there’s one difference: the system at the heart of our email infrastructure is homegrown. This week, Ron talks to Dominick LoBraico, an engineer working on Jane Street’s technology infrastructure, about how and why we built Mailcore, an email server written and configured in OCaml. They delve into questions around how best to represent the configuration of a complex system, when you should build your own and when you shouldn’t, and the benefits of bringing a code-focused approach to solving systems problems.You can find the transcript for this episode along with links to things we discussed on our website.

Language design with Leo White

Language design with Leo White

Equal parts science and art, programming language design is very much an unsolved problem. This week, Ron speaks with Leo White, from Jane Street's Tools & Compilers team, about cutting-edge language features, future work happening on OCaml, and Jane Street's relationship with the broader open-source community. The conversation covers everything from the paradox of language popularity, to advanced type system features like modular implicits and dependent types. Listen in, no programming languages PhD required!You can find the transcript for this episode along with links to things we discussed on our website.

Clock synchronization with Chris Perl

Clock synchronization with Chris Perl

Clock synchronization, keeping all of the clocks on your network set to the “correct” time, sounds straightforward: our smartphones sure don’t seem to have trouble with it. Next, keep them all accurate to within 100 microseconds, and prove that you did -- now things start to get tricky. In this episode, Ron talks with Chris Perl, a systems engineer at Jane Street about the fundamental difficulty of solving this problem at scale and how we solved it.You can find the transcript for this episode along with links to things we discussed on our website.

Python, OCaml, and Machine Learning with Laurent Mazare

Python, OCaml, and Machine Learning with Laurent Mazare

A conversation with Laurent Mazare about how your choice of programming language interacts with the kind of work you do, and in particular about the tradeoffs between Python and OCaml when doing machine learning and data analysis. Ron and Laurent discuss the tradeoffs between working in a text editor and a Jupyter Notebook, the importance of visualization and interactivity, how tools and practices vary between language ecosystems, and how language features like borrow-checking in Rust and ref-counting in Swift and Python can make machine learning easier.You can find the transcript for this episode along with links to things we discussed on our website.

Compiler optimization with Greta Yorsh

Compiler optimization with Greta Yorsh

It’s a software engineer’s dream: A compiler that can take idiomatic high-level code and output maximally efficient instructions. Ron’s guest this week is Greta Yorsh, who has worked on just that problem in a career spanning both industry and academia. Ron and Greta talk about some of the tricks that compilers use to make our software faster, ranging from feedback-directed optimization and super-optimization to formal analysis.You can find the transcript for this episode along with links to things we discussed on our website.

Multicast and the markets with Brian Nigito

Multicast and the markets with Brian Nigito

Electronic exchanges like Nasdaq need to handle a staggering number of transactions every second. To keep up, they rely on two deceptively simple-sounding concepts: single-threaded programs and multicast networking. In this episode, Ron speaks with Brian Nigito, a 20-year industry veteran who helped build some of the earliest electronic exchanges, about the tradeoffs that led to the architecture we have today, and how modern exchanges use these straightforward building blocks to achieve blindingly fast performance at scale.You can find the transcript for this episode along with links to things we discussed on our website.

Build systems with Andrey Mokhov

Build systems with Andrey Mokhov

Most software engineers only think about their build system when it breaks; and yet, this often unloved piece of software forms the backbone of every serious project. This week, Ron has a conversation with Andrey Mokhov about build systems, from the venerable Make to Bazel and beyond. Andrey has a lot of experience in this field, including significant contributions to the replacement for the Glasgow Haskell Compiler’s Make-based system and Build Systems à la carte, a paper that untangles the complex ecosystem of existing build systems. Ron and Andrey muse on questions like why every language community seems to have its own purpose-built system and, closer to home, where Andrey and the rest of the build systems team at Jane Street are focusing their efforts.You can find the transcript for this episode along with links to related work on our website.