Senior Java Engineer - Layer-1 Blockchain I'm working with a Layer-1 blockchain company building its core systems from the ground up. The team is small and senior, and this role will have a direct impact on the architecture and performance of the network. Responsibilities You may be doing all of the following: Inventing new protocols, data structures, and algorithms to solve novel problems Designing and writing low-latency, high-throughput Java systems from scratch Tuning memory usage to the byte and measuring performance to the nanosecond Writing parsers, interpreters, and other core infrastructure from first principles Mentoring engineers and leading complex technical initiatives Creating tools and profilers to measure and improve execution across the stack Making design decisions that affect the correctness of a public ledger Moving between system-level design and single-instruction-level optimization Building tests and harnesses that ensure long-term stability Requirements 10 years of professional software development experience Deep expertise in Java and the JVM (memory model, threading, GC, profiling) Experience with parsers, interpreters, compilers, or other language tooling Proven ability to write and optimize high-performance code with minimal dependencies Strong foundation in algorithms, data structures, and concurrency Significant experience building systems where performance and correctness are critical Ability to build from scratch with just an IDE and the JDK Hands-on with tools such as JMH, PBJ, async-profiler, JFR, Solo, YourKit, or similar Passion for code quality, system design, and correctness Master's degree in Computer Science (or equivalent experience) Nice to have Experience in distributed systems and/or blockchain Knowledge of cryptographic primitives (hashes, public/private keys) Familiarity with Web3 tools or smart contract platforms (especially EVM) Background in event-driven architectures or high-frequency trading systems Understanding of test-driven development and CI practices Note This is a challenging role. It requires engineers who enjoy solving deep technical problems and building systems where every line of code matters. If this is you - and you live in US, Europe, or main centres then send me a CV which fits the above JD to simon@cryptorecruit.com If your CV is a fit - I'll be in touch!