Java Backend Developer Jobs

Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me , Do the Right Thing , and Get Things Done . These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. About the Liquidity Platform The Liquidity Platform provides cutting-edge technology that covers all aspects of crypto trading. We build low-latency connectivity to global crypto venues — across both CeFi and DeFi — strategy services for automated pricing and trading bots, high-frequency data capture and analysis, and state-of-the-art micro frontends for trading management. On top of this infrastructure, we build highly customized strategies to facilitate crypto liquidity. Our engineering teams own the full trading lifecycle, from venue connectivity and execution to strategy, data, risk, and analytics. Our risk solutions are independent of trading logic, decoupled by design, and connected to 20+ trading venues across spot, derivatives, and event-contract markets. If you are a strong technologist excited about the potential of crypto trading and fully-automated systematic trading, we should talk. About the Role We are hiring software engineers across the Liquidity Platform’s engineering teams. You will design, build, and operate the systems that price, execute, monitor, and safeguard our liquidity-providing business 24/7. You will work closely with liquidity managers, product managers, and desk developers — developing strategies, services, and infrastructure using in-hou

About the Team Our team brings OpenAI’s most capable technology to the world through our developer platform: the OpenAI API. As the leading AI development platform, our API is used by millions of developers and the majority of enterprises around the world, and powers the majority of AI applications that you may use on a daily basis. The platform supports everything from simple model calls to stateful, multimodal, tool-using applications through the Responses API, Agents SDK, Realtime API, and more. Our SDKs turn that fast-moving platform into reliable, idiomatic developer experiences across languages. About the Role We are looking for a software engineer to help build the official SDKs that power the OpenAI API. Currently offered in Python, Node.js, Golang, Java, and Ruby – our SDKs are some of the most popular in the world. You will help shape the developer experience for all new API features, as well as all future versions of our APIs. We’re looking for engineers who are deeply immersed in AI-native development: people who actively build with Codex and other coding agents, have developed agentic applications or developer tools, and bring strong, experience-backed opinions about OpenAI’s APIs. You’ll pair that firsthand product intuition with meticulous SDK design to improve how developers build with our platform. Prior experience building SDKs is lovely, but not absolutely necessary. In this role, you will: Define and implement the SDK experience for all new API features, as well as all future versions of our API. Build and experiment with agentic applications, developer tools, and coding-agent workflows using Codex and OpenAI’s APIs, translating firsthand experience into better SDK abstractions, API ergonomics, and developer experiences. Build and maintain our systems to make SDK maintenance and generation streamlined and automated. Contribute to our SDK strategy and roadmap, including which languages to support and what features to support. Collaborate closely w

Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me , Do the Right Thing , and Get Things Done . These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. About the Opportunity You will be responsible for the core architecture design and technical delivery of an enterprise-grade AI Native engineering platform, driving the deep integration of large language models, AI Agents, knowledge capabilities, and the software development lifecycle. The platform will support intelligent capabilities across requirement analysis, solution generation, coding collaboration, test automation, and environment orchestration.This role focuses on engineering-grade AI implementation in complex R&D scenarios. You are expected to turn model capabilities into reusable, scalable, and governable platform capabilities, and continuously drive the evolution of the engineering platform toward an AI Native architecture. What You’ll Be Doing Lead the overall architecture design and core capability development of the AI Agent platform, including task orchestration, tool invocation, context management, memory mechanisms, and multi-agent collaboration. Drive the implementation of AI Native capabilities in engineering workflows , including AI coding, technical solution generation, test case generation, test report generation, and automated environment deployment. Build the knowledge augmentation layer for the platform, including the d

Who we are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me, Do the Right Thing, and Get Things Done. These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more. About the Team The AI Engineering team is responsible for integrating different AI models with different business lines. You'll need to understand how these models function in diverse domains and develop efficient integration solutions. This team is building the company's crawler platform, supporting multiple areas such as Compliance, Trading, Financial Products, and Business Intelligence. What You’ll Be Doing Understand different AI models’ feature Understand different business domains’ feature Provide integration solutions for AI models into the business domain Maintain systems’ high availability and high throughput Improve technology best practices and code reviews for peers Build and maintain various AI infrastructure / platform What We Look For In You Bachelors in Science / Technology / Engineering / Mathematics Experience in AI Agent / RAG engineering solutions Experience in Microservices / API development with Java/SpringBoot/SpringCloud/Python/Langchain Knowledgeable in multi-threading and distributed architecture. Understanding of mainstream messaging frameworks including Kafka etc. Knowledge of different d

OKX will be prioritising applicants who have a current right to work in Singapore, and do not require OKX's sponsorship of a visa About OKX At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me, Do the Right Thing, and Get Things Done. These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more. About the Opportunity The Trading Systems team builds the mission-critical order, execution, position, and risk infrastructure that powers OKX’s global trading platform. We operate at the intersection of high performance, correctness, resilience, and scale—where every design decision matters. We are seeking a Senior C++ Software Engineer to lead the design and evolution of our trading counter and core trading systems. This role is for an engineer who combines deep systems expertise with strong ownership: someone who investigates root causes, raises the quality bar across the engineering lifecycle, and turns individual learning into reusable team capability. What You’ll Be Doing Lead the architecture, design, and development of complex, high-performance C++ trading systems. Design reliable distributed systems, including consistency, fault tolerance, disaster recovery, and resilience strategies across system boundaries. Own work end to end—from technical proposals and design reviews through framew

Lithic is the modern card issuing and processing platform empowering ambitious financial companies to build the future of payments. Our infrastructure powers card programs for 100+ innovative clients, from fintechs reimagining credit and digital banking to platforms transforming disbursements and spend management. Companies like Mercury, Flex, and Novo rely on Lithic's developer-friendly APIs, direct network connections, and flawless reconciliation to launch and scale card programs in weeks, not years. We're building a future where access to better financial products materially improves people's lives, free from the constraints of 30-year-old mainframes and legacy processors. We're proud to be backed by world-class investors who share that vision, including Bessemer Venture Partners, Index Ventures, Spark Capital, Stripes, and Mastercard, along with many others. We're a team of 170+ across 26 states and 7 countries, headquartered in New York City. Position: Senior Software Engineer, Processing Location: Remote We are hiring a Senior Software Engineer for our Processing team to lead Lithic’s next phase of growth. The Processing team builds and maintains the real-time interfaces between Lithic and external payment networks. Every card authorization, clearing message, and settlement file flows through systems this team owns. The team manages both online and batch transaction flows across Mastercard, Visa, and Amex, along with transaction enrichment, disputes processing, and network compliance. The systems we maintain have strict latency and uptime requirements, because they sit on the critical path for every card transaction. The team also manages the physical network peering with card network partners, so infrastructure and networking expertise are important. The team primarily uses Java, Python, and Kotlin on AWS. What you'll do: Ensure high reliability, low latency, and correctness for Lithic's transaction processing interfaces and related services Devel

OKX will be prioritising applicants who have a current right to work in Hong Kong, and do not require OKX's sponsorship of a visa. Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me , Do the Right Thing , and Get Things Done . These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more. About The Team Own the account backbone of a CeFi platform trusted by millions — login, registration, account security, MFA, Passkey — where a single security regression is measured in real user funds. The more senior you are, the more you set the technical direction others build on. What You'll Be Doing Own account-system subsystems end-to-end — authentication, MFA, Passkey/WebAuthn, session & device trust, account registration and recovery — including architecture, tradeoffs, and long-term evolution. Design flows that are secure and low-friction at millions-of-DAU scale — the hardest tradeoff in this space. Partner with risk & security teams to turn threat models into shipped mobile defenses. Build our AI-native engineering practice — design automated development workflows and harness systems (agents, evals, guardrails, CI integration) that let AI do real engineering work, while safeguarding delivery quality and efficiency . Raise the bar t

OKX will be prioritising applicants who have a current right to work in Hong Kong, and do not require OKX's sponsorship of a visa. Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me , Do the Right Thing , and Get Things Done . These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more. About The Team Own OKX's in-app messaging end to end — from a fully in-house IM engine to a messaging platform powering community chat, payments, VIP service, and user-to-agent (AI) chat for millions. The more senior you are, the more you set the technical direction others build on. What You'll Be Doing Build our multi-platform unified IM SDK — unify the logic core across platforms and push performance and stability as a lever for growth. Platformize the engine — turn it into a platform that product teams build business scenarios on (community chat, payments, VIP service). Build user-to-agent (AI) chat — the conversational AI surface on top of IM, from real-time delivery to the agent interaction experience. Own delivery end-to-end — real-time WebSocket long-connection and offline push across overseas + China vendor channels — so messages reach users whether the app is open or not. Push latency, reliability, and battery/memory to their limits under rea

OKX will be prioritising applicants who have a current right to work in Singapore, and do not require OKX's sponsorship of a visa. Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me , Do the Right Thing , and Get Things Done . These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more. About The Opportunity We are building the foundational data infrastructure that powers one of the world's leading crypto exchanges. As a Big Data Platform Engineer , you will design, build, and evolve the core platform services that enable hundreds of data engineers and analysts to move fast and ship reliable pipelines. You will be at the forefront of our AI agent initiative — embedding LLM-driven capabilities directly into the platform layer so that scheduling, cost optimization, and incident response increasingly run autonomously. What You’ll Be Doing Platform Core: Design and operate large-scale distributed data systems Own the big data compute and storage infrastructure (MaxCompute/ODPS, Hologres, Spark) Build and maintain multi-site task orchestration that dynamically selects engines and enforces policy Drive reliability and performance improvements across batch and real-time pipelines AI Integration: Build the AI-native platform layer Develop an

OKX will be prioritising applicants who have a current right to work in Singapore, and do not require OKX's sponsorship of a visa. Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me , Do the Right Thing , and Get Things Done . These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more. About The Opportunity As a Technical Expert, you will lead the development of the company’s core security engineering and DevSecOps capabilities, with a strong focus on security product development, platform engineering, and SDK /Agent development . The ideal candidate should demonstrate deep security expertise, broad technical coverage, strong hands-on engineering capability, and exceptional influence in driving security governance across business teams . What You’ll Be Doing Lead the architecture and core development of the company’s end-to-end DevSecOps platform, security products, and SDKs/Agents , covering code, build, artifacts, images, deployment, and runtime security. Own the design and development of RASP / Java Agent runtime protection , leveraging ASM, ByteBuddy, and Java Instrumentation for bytecode enhancement, runtime hooks, detection and blocking engines, while continuously improving performance, stability, and compatibility.

OKX will be prioritising applicants who have a current right to work in Hong Kong, and do not require OKX's sponsorship of a visa. Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me , Do the Right Thing , and Get Things Done . These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more.\ About The Opportunity As a mobile software engineer, you will build and maintain a core OKX app with millions of daily active users. You will work cross-functionally with design, product and other engineering teams to identify customer needs, and ship high-quality new features through fast iterations. This is an opportunity to learn the full life cycle of crypto mobile applications including pro/retail trading, asset management and wallet. Join us in building the next generation of mobile-first Web3 experiences, empowering millions of users to seamlessly interact with digital assets, decentralized applications, and blockchain-powered services through secure and intuitive products. What You’ll Be Doing Part of a global mobile team, developing new features for the all-in-one iOS and Android apps. Strive for performance optimization and maximize customer satisfaction. Stay on top of industry trends, and evaluate new solutions to address our unique and fast-growing bu

OKX will be prioritising applicants who have a current right to work in Singapore, and do not require OKX's sponsorship of a visa. Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me , Do the Right Thing , and Get Things Done . These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more. About The Opportunity As a mobile software engineer, you will build and maintain a core OKX app with millions of daily active users. You will work cross-functionally with design, product and other engineering teams to identify customer needs, and ship high-quality new features through fast iterations. This is an opportunity to learn the full life cycle of crypto mobile applications including pro/retail trading, asset management and wallet. Join us in building the next generation of mobile-first Web3 experiences, empowering millions of users to seamlessly interact with digital assets, decentralized applications, and blockchain-powered services through secure and intuitive products. What You’ll Be Doing Part of a global mobile team, developing new features for the all-in-one iOS and Android apps. Strive for performance optimization and maximize customer satisfaction. Stay on top of industry trends, and evaluate new solutions to address our unique and fast-grow

OKX will be prioritising applicants who have a current right to work in Singapore, and do not require OKX's sponsorship of a visa. Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me , Do the Right Thing , and Get Things Done . These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more. About the Opportunity You will be responsible for the core architecture design and technical delivery of an enterprise-grade AI Native engineering platform, driving the deep integration of large language models, AI Agents, knowledge capabilities, and the software development lifecycle. The platform will support intelligent capabilities across requirement analysis, solution generation, coding collaboration, test automation, and environment orchestration.This role focuses on engineering-grade AI implementation in complex R&D scenarios. You are expected to turn model capabilities into reusable, scalable, and governable platform capabilities, and continuously drive the evolution of the engineering platform toward an AI Native architecture. What You’ll Be Doing Lead the overall architecture design and core capability development of the AI Agent platform, including task orchestration, tool invocation, context management, memory mechanisms, and multi-agent colla

Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me , Do the Right Thing , and Get Things Done . These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more. Key Responsibilities Design and optimize high throughput order execution systems with sub-millisecond latency targets Build real time market data pipelines aggregating order books and price feeds from multiple exchanges Implement position tracking with exchange reconciliation, risk limits, and multi account support Develop exchange connectivity using FIX 5.0+, WebSocket, and HTTP/2 protocols Profile and eliminate latency hotspots using garbage free coding and lock free concurrency Implement pre-trade risk controls, circuit breakers, and rate limiters Qualifications Solid STEM (Science/Technology/Engineering/Mathematics) education background. 5-8 years software development experience, preferably in trading/oms/latency sensitive systems Strong Java 17+ proficiency with understanding of JVM internals and GC behavior Hands-on experience with FIX 5.0+, WebSocket, and HTTP/2 protocols Solid multi-threaded programming and concurrent systems knowledge Understanding of order lifecycle and market microstructure basics Strong problem solving skills and attention to detail Excellent co

Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves. Across our multiple offices globally, we are united by our core principles: We Before Me , Do the Right Thing , and Get Things Done . These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more. About the Opportunity You will join our Data & Analytics team, which owns two core data domains end to end: • Public market data — trades, quotes, funding, and full order-book data continuously captured from global crypto exchanges at petabyte scale. • Proprietary trading data — orders, fills, positions, balances, and settlement activity streamed from internal desks and systems. We are one team rather than separate engineering and analytics functions. The same people build pipelines, model data, validate its correctness, and answer the business questions it supports. You will see data problems through end to end: from the exchange connection or internal source through to the analysis produced from it. This is an exciting time to join. We are rebuilding the platform on ClickHouse, Apache Iceberg, and Kafka while continuing to support live trading. The work combines substantial platform design with hands-on ownership of business-critical data. What You’ll Be Doing • Build and operate pipelines that bring market and trading data into our platform, including ingestion, pars