Latest Interviews

A Look Inside Jane Street’s Internship Program 2026

A candidate from an aerospace and computer science background secured an internship at Jane Street by solving a puzzle and demonstrating a collaborative problem-solving approach during interviews. During the role, the intern built a tool for bond desks and optimized GPU memory management using autoencoders, with the resulting code now deployed in active training systems. The experience highlighted a firm culture that values learning from mistakes and adaptability, featuring mentorship in a commodities trading project and social connections through shared hobbies like the Irish fiddle.

8 Figures on a Design Doc

Jacob Baskin

Before launching its "Superstore" system, Jane Street authorized a small team to purchase 10 petabytes of storage appliances for approximately $80 million based solely on a design document. This rapid, high-stakes capital expenditure of eight figures, which starkly contrasts with the centralized allocation processes the decision-maker previously encountered at Google, highlights the firm's unique operational agility. The speaker describes this unprecedented scale of immediate spending as both impressive and nervously significant for an organization of its size.

Building a Data Warehouse From Scratch with Jacob Baskin

Jacob Baskin, Ron

Jacob Baskin's career spans mechanism design research at Brown, building real-time ad exchanges at Google, and attempting to digitize urban parking infrastructure. At Jane Street, he engineered the SuperStore distributed database to replace legacy monoliths and designed the auction-based resource allocation system for the massive Hive compute cluster. His current work focuses on refining these mechanisms by addressing utility gaps in bidding models and implementing scalable data distribution architectures to support large-scale machine learning and simulation tasks.

Jane Street on GPUs, Trading, and Hiring: A Conversation with Dwarkesh

Jane Street, Dwarkesh Patel, Ron Minsky, Dan Pontecorvo

Jane Street executes a multi-tiered trading strategy that balances nanosecond-scale FPGA execution with long-horizon AI models while transitioning to a disaggregated global network featuring a $6 billion compute partnership with CoreWeave. The firm prioritizes model architecture diversity and custom hardware, including ARM and NVIDIA infrastructures, to navigate high-noise financial data without relying on single foundation models. This approach is supported by a hiring strategy focused on scarcity-driven talent acquisition and a human-in-the-loop philosophy that maintains critical judgment during complex market anomalies.

Why Testing Is Hard and How to Fix It with Will Wilson

Will Wilson, Ron Minsky

Antithesis CEO Will Wilson founded the company to solve the non-determinism and state-space explosion challenges that plague traditional testing in complex distributed systems. The platform utilizes hypervisor-level emulation to create deterministic simulations of unmodified software, enabling exhaustive state-space exploration without the need for extensive manual test definitions. This approach has attracted major institutional users like Jane Street, which serves as both a customer and a Series A investor to validate the tool's efficacy in finding critical concurrency bugs and accelerating AI-driven development cycles.

Bryan Cantrill: Andreessen’s Folly - The False Dichotomy of Software and Hardware

Bryan Cantrill, Andreessen, Alan Kay, Jonathan Gruber, Trevor Johnsen, Tred Wansell, Jermaine

Speaker critiques Marc Andreessen's "Software Eating the World" thesis as a false dichotomy while detailing Oxide Computer Company's hardware-software co-design strategy to reclaim stack control. By abandoning proprietary layers like UEFI and Baseboard Management Controllers in favor of custom operating systems and holistic integration with AMD silicon, the company addresses systemic reliability failures that plague commoditized reference designs. This approach has already resolved complex hardware-software interaction bugs and positions the firm to pursue open-source firmware and transparent accelerator partnerships to eliminate vendor lock-in in future data center infrastructure.

The Thermodynamics of Trading with Daniel Pontecorvo

Daniel Pontecorvo, Ron Minsky, Dan Pontecorvo, Mark Mirchandani, David Abelson

Jane Street's physical engineering team manages a complex lifecycle of data centers and offices, prioritizing microsecond-level latency constraints and evolving from traditional air cooling to high-density liquid immersion solutions for AI infrastructure. The organization deploys proprietary monitoring stacks to prevent catastrophic failures while optimizing Power Utilization Efficiency through economizer cycles and rear-door heat exchangers that handle rack densities up to 170 kW. Their human-centric workspace design leverages modular furniture and circadian lighting to sustain collaboration, supported by a hiring strategy that blends industry veterans with graduates to challenge established engineering assumptions.

The Saga of Multicore OCaml

After a nine-year development cycle, Jane Street successfully deployed Runtime 5, a multi-core garbage collector for OCaml that addresses initial performance regressions through a redesigned pacing model and a Mark Delay synchronization patch. The team resolved complex "load-bearing bugs" and floating garbage issues to achieve stable parallelism while maintaining the sequential performance required for high-frequency trading environments. Despite rejecting the ownership model of languages like Rust, Jane Street is now releasing its production-ready OxCamel branch to facilitate researcher experimentation on future parallelism tools and type-level race freedom guarantees.

Building Tools for Traders with Ian Henry

Ian Henry, Ron Minsky, Mark Mandelbaum, Mark Mirchandani, David Eastman, Brian Dorsey

Ian Henry, a Jane Street engineer who transitioned from general web development to options trading tools, leverages the firm's custom OCaml ecosystem to build high-density interfaces that eliminate mouse usage and manage complex volatility surfaces. His recent work includes creating Bauble, a live 3D graphics environment in the Janet language that demonstrates how side projects using image-based state serialization and novel macro systems can rapidly inform internal production tooling. Through this process, Henry illustrates how Jane Street bridges the gap between low-latency exchange architecture and expert user needs by prioritizing type safety, extreme information density, and a parallel software universe free from standard web protocols.

The Uncertain Art of Accelerating ML Models with Sylvain Gugger

Sylvain Gugger, Ron Minsky, Jeremy Howard, Mark Mandelmann, Mark Mirchandani, Francesc Campoy, Gabriel Sanchez

Former fast.ai co-author Jeremy Howard discusses his transition from mathematics education to optimizing machine learning infrastructure at Jane Street, highlighting breakthroughs in learning rate schedules and image resizing that previously secured top benchmark placements. He details the development of the Hugging Face Accelerate library, a lightweight tool designed to abstract complex hardware parallelism and eliminate boilerplate code for training across diverse GPUs and TPUs. The discussion further explores the architectural constraints of financial data, the dominance of PyTorch's iterative execution model, and Jane Street's rigorous approach to reproducibility and custom model development for high-frequency trading.

From the Lab to the Trading Floor: Designing for Expert Users with Erin Murphy

Erin Murphy, Ron Minsky

Erin Murphy discusses her evolution from creating data visualization portals at NASA's Jet Propulsion Laboratory to implementing formal UX processes at Jane Street, where she addresses the unique needs of technical experts requiring high information density and keyboard-driven workflows. By prioritizing functional clarity over consumer aesthetics, Murphy leads initiatives that transition complex legacy tools into web-based interfaces while leveraging informal, ad-hoc user observations to maintain design agility within a rapidly scaling engineering environment. Her approach emphasizes recruiting domain-expert designers who can partner with engineers to solve high-complexity problems, ultimately aiming to bridge the gap between graphical usability and the composability of command-line interfaces.

Performance Engineering on Hard Mode with Andrew Hunter

Andrew Hunter, Ron Minsky

This analysis contrasts the performance engineering strategies of hyperscalers, which prioritize broad infrastructure optimization for massive scale, against Jane Street's focus on deterministic latency reduction for specialized trading systems. The discussion details measurement trade-offs between statistical sampling and hardware tracing, while examining how OCaml engineers overcome memory locality gaps through zero-allocation dialects and low-overhead C interop. Ultimately, the presentation advocates for developing mechanical sympathy and accelerating OODA loops to shift optimization discipline from micro-tuning to systemic architectural design.

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

Peter Bogart-Johnson, Ron Minsky

Peter Bogart-Johnson, formerly a D.E. Shaw researcher, joined Jane Street three years ago to formalize program management as the firm expanded to over 2,000 employees, successfully transitioning from ad-hoc engineering coordination to a structured discipline that bridges technical and non-technical workflows. His approach emphasized low-latency communication tools and an "anthropological" onboarding strategy that mitigated early engineer resistance by prioritizing empathy and incremental trust-building over rigid frameworks. These efforts enabled a critical 2023 strategic pivot toward machine learning, where program managers now facilitate rapid infrastructure scaling and high-stakes experimentation while balancing consensus-driven decision-making with the urgent demands of new GPU deployments.

The Future of Programming with Richard Eisenberg

Richard Eisenberg, Ron Minsky

Richard Eisenberg joined Jane Street's tools and compilers team to lead the development of "unbox types" for OCaml, a feature designed to eliminate runtime pointer indirections while retaining garbage collection. Previously an eight-year Haskell ecosystem contributor who chaired the Haskell Foundation, Eisenberg brings extensive experience in type theory and compiler design to address OCaml's memory representation challenges. His work involves a careful trade-off between parametric polymorphism and performance optimization, tested internally before seeking community consensus for upstream integration.

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

Ella Ehrlich, Ron Minsky

Jane Street engineers are modernizing the legacy Gord trading infrastructure by migrating its distribution layer to Kafka, implementing automated release pipelines, and refactoring data normalization to ensure high availability and scalability. These technical upgrades, which include shifting from push to pull-based data delivery and eliminating manual global deployment processes, directly support the system's goal of achieving 24/7 uptime without daily resets. Concurrently, the firm is expanding its engineering pipeline through targeted diversity initiatives like the Insight and InFocus programs, which have successfully raised female intern representation to 25% while establishing long-term relationships with underrepresented minority candidates.