Senior Engineer, Custody Engineering (C++, L1 Onboarding)

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: Custody Engineering

The Custody Engineering Team builds the critical systems that safeguard user assets, architecting secure and compliant infrastructure for the entire lifecycle of funds. Our technical scope is broad, spanning blockchain development, smart contracts, oracles, and the full-stack systems that power them. We operate with a high degree of autonomy and ownership over mission-critical infrastructure, bridging the gap between cutting-edge blockchain technology and institutional-grade stability.

What You’ll Do

• Library Architecture: Architect and maintain high-performance, reusable C++ libraries and services that form the backbone of the platform.

• Blockchain Integration: Build core custody solutions that interface directly with public blockchains for secure asset management.

• Performance Engineering: Drive continuous optimization for latency, throughput, and system resource usage.

• System Hardening: Diagnose and resolve low-level system bottlenecks and stability challenges while enforcing high code quality standards.

• Technical Ownership: Lead end-to-end feature development and resolve complex reliability issues in a high-concurrency environment.

What You’ll Bring

• Industry Experience: 5+ years of software engineering experience building production systems (e.g., FinTech, HFT, or Systems Programming).

• Language Mastery: Deep technical command of modern C++ (C++11/17+), including STL, Boost libraries, and template metaprogramming.

• Systems Knowledge: Deep understanding of Linux internals, multi-threading, concurrency patterns, and inter-process communication (IPC).

• Operational Excellence: Commitment to rigorous unit testing, performance benchmarking, and debugging low-level system failures.

• Autonomous Operation: Demonstrated ability to operate independently with minimal guidance in a high-stakes, fast-paced environment.

• Communication: The ability to articulate architectural decisions and low-level trade-offs to both technical and non-technical stakeholders across global teams.

• Education: Bachelor’s degree in Computer Science, Engineering, or a related field (or equivalent professional experience).

Nice To Haves

• Engineering experience within the finance, high-frequency trading, or high-security sectors

• Familiarity with private or public blockchain architecture and digital asset custody patterns

• Exposure to smart contract development or interaction

• Applied knowledge of cryptography primitives and security protocols

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.