About Bullish

Bullish is an institutionally focused global digital asset platform that provides market infrastructure and information services. These include: Bullish Exchange – a regulated and institutionally focused digital assets spot and derivatives exchange, integrating a high-performance central limit order book matching engine with automated market making to provide deep and predictable liquidity. Bullish Exchange is regulated in Germany, Hong Kong, and Gibraltar. CoinDesk Indices – a collection of tradable proprietary and single-asset benchmarks and indices that track the performance of digital assets for global institutions in the digital assets and traditional finance industries. CoinDesk Data - a broad suite of digital assets market data and analytics, providing real-time insights into prices, trends, and market dynamics. CoinDesk Insights – a digital asset media and events provider and operator of Coindesk.com, a digital media platform that covers news and insights about digital assets, the underlying markets, policy, and blockchain technology.

Reports to:

Engineering Organization & Culture

At Bullish, we are engineering the institutional standard for the digital asset industry. Our mission is to build a platform where security and compliance are the foundational core, requiring a commitment to technical excellence that goes beyond simply delivering code. We operate as a global engineering organization, setting a high bar in a demanding environment for those driven to do the best work of their careers alongside world-class peers.

We value engineers who treat development as a craft and own the outcome from concept to deployment. You will be expected to navigate the unknown, bring structure to ambiguity, and help shape the frameworks and processes that drive our global teams forward. We refuse to compromise on quality and seek problem solvers who thrive on high-impact technical challenges.

The Team: Trading Platform Engineering

The Trading Platform Engineering team is responsible for designing and optimizing the high-performance, mission-critical foundation that powers our trading activities. Operating at the intersection of software and hardware, the team builds low-latency systems that demand expert-level proficiency in Linux kernel internals, networking pipelines, and distributed systems architecture. The team focuses on architectural excellence, reliability, determinism, and the relentless elimination of tail latency.

What You’ll Do

• High-Performance Service Development: Design, build, and optimize high-performance systems using C and Java.

• Kernel & User Space Engineering: Engineer performance-critical components across user space and kernel interfaces, focusing on memory, scheduling, I/O, and networking paths.

• Advanced Networking: Develop and tune networking pipelines (multicast/unicast UDP and TCP) and implement kernel-bypass or fast-path networking (e.g., DPDK, XDP).

• Kernel Optimization: Interact with and optimize Linux kernel subsystems, including memory management, schedulers, device drivers, and filesystems (VFS).

• Latency & Determinism: Optimize systems for deterministic latency through CPU isolation, thread pinning, NUMA locality, cache awareness, and lock contention reduction.

• Distributed Systems: Apply distributed systems patterns, such as sequencer (virtual synchrony), for total ordering and consistency.

• Profiling & Debugging: Use tools like perf, strace, eBPF, and flame graphs to identify and eliminate system bottlenecks.

• Operational Excellence: Collaborate cross-functionally to deliver robust production systems with clear SLOs, reproducible performance tests, and actionable runbooks.

What You’ll Bring

• Language Mastery: Expert-level proficiency in Java

• Linux Internals: Deep understanding of Linux kernel internals, including memory management, driver models, and scheduler tuning.

• Low-Latency Expertise: Practical experience in end-to-end latency optimization, jitter reduction, and techniques like lock-free or wait-free programming.

• Networking Depth: Experience with socket options, buffer sizing, epoll, io_uring, RSS, and NIC queue configuration.

• Distributed Systems Knowledge: Understanding of sequencer-based total order broadcast, partial order broadcast and the tradeoffs between latency, throughput, and availability.

• Concurrency & Systems: Solid understanding of concurrency, synchronization primitives, and memory models.

• Analytical Mindset: A focus on measurement over assumption, using benchmarks and profiles to drive decisions and communicate complex tradeoffs.

• Collaborative Craftsmanship: Commitment to high code quality through rigorous reviews, mentoring, and clear documentation.

Nice To Haves

• Trading Infrastructure: Experience in financial markets (e.g., market data, order routing, or FIX/exchange-native protocols).

• Time Synchronization: Familiarity with PTP or other high-precision time synchronization for low-latency environments.

• Observability: Experience using eBPF and tracing for observability in production.

• Hardware Interfacing: Knowledge of RDMA, NIC offloads (TSO, LRO), or experience maintaining kernel modules and device drivers.

• JVM Tuning: Experience with low-latency JVM practices and deterministic GC tuning for Java-based systems.

• Advanced Benchmarking: Deep knowledge of benchmarking methodology, including workload design and variance analysis.

Bullish is proud to be an equal opportunity employer. We are fast evolving and striving towards being a globally-diverse community. With integrity at our core, our success is driven by a talented team of individuals and the different perspectives they are encouraged to bring to work every day.