Java Developer Jobs

MongoDB’s mission is to empower innovators to create, transform, and disrupt industries by unleashing the power of software and data. We enable organizations of all sizes to easily build, scale, and run modern applications by helping them modernize legacy workloads, embrace innovation, and unleash AI. Our industry-leading developer data platform, MongoDB Atlas, is the only globally distributed, multi-cloud database and is available in more than 115 regions across AWS, Google Cloud, and Microsoft Azure. Atlas allows customers to build and run applications anywhere—on premises, or across cloud providers. With offices worldwide and over 175,000 new developers signing up to use MongoDB every month, it’s no wonder that leading organizations, like Samsung and Toyota, trust MongoDB to build next-generation, AI-powered applications. Atlas Search is a multi-cloud service that allows users to execute complex full text and vector search queries using the MongoDB Query Language . Our users are free to focus on relevance and data retrieval instead of the machinery needed to search data at scale. Our team builds and maintains the instances and supporting infrastructure powering Atlas Search. This platform deploys and monitors search deployments, providing a highly scalable yet observable system for customers and engineers. The Atlas Search product is quickly gaining traction with customers and we are shipping core infrastructure components that enable this growth. This role is based in San Francisco, CA with an in-office or hybrid work model. Successful candidates will have the following qualities: 2+ years of hands-on experience designing, building, testing, and maintaining industrial-strength backend software and automation in complex codebases Experience developing distributed systems and multithreaded applications Familiarity with public cloud platforms, distributed infrastructure, and metric-based development Experience with at least one modern statically typed program

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 Team The DEX Token Markets team at OKX Web3 builds real-time market tracking and analysis tools across 40+ chains and hundreds of thousands of trading pairs — charts, trade feeds, watchlists, alerts, and screeners trusted by millions of traders navigating DeFi, including the fast-moving meme coin markets driving much of today's on-chain volume. What You'll Be Doing Build and maintain the market tracking platform, including systems tuned for meme coin-style volume spikes and liquidity swings. Develop high-throughput, low-latency backend systems that keep data accurate and reliable under bursty load. Troubleshoot issues to ensure service stability and quality. Ship features on time with clean, well-tested, maintainable code. Collaborate with product and engineering to keep integrations running smoothly. What We Look For In You Bachelor's/Master's in CS, Software Engineering, or related (or strong STEM background). 3-5+ years building high-

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 team: OKX data team is responsible for the whole data scope of OKG, from techincal selection, architecture design, data ingestion, data storage, ETL, data visualization to business intelligence and data science. We are data engineers, data analysts and data scientists. The team has end-to-end ownership of most of the data at OKx throughout the whole data lifecycle including data ingestion, data ETL, data warehouse and data services. As a data engineer of the team, you will work with the team to leverage data technologies to empower evidence-based decision-making and improve the quality of the company's products and services. Responsibilities: Proficient in mainstream cloud computing and big data technologies such as Hadoop, Hive, Flink, YARN, Elasticsearch (ES), Kafka , etc. Expert in real-time big data processing using Flink , with solid experience in Flink SQL development . Build and optimize offline and real-time data pipeline

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 team The Growth Team at OKX is a dynamic group of professionals dedicated to accelerating OKX’s expansion through innovative strategies, data-driven insights, and continuous optimization. By tackling intricate business logic at scale, tapping into emerging DeFi growth opportunities, and addressing globalization and localization challenges, the team drives impactful user acquisition, engagement, and retention across global markets Responsibilities Collaborate with Product, Design, and Marketing teams to deliver rapid, cross-functional innovation Architect and maintain high-performance, highly available distributed services Explore emerging opportunities in DeFi to promote growth and bridge centralized and decentralized solutions Solve complex business logic challenges and drive improvements for global user experiences Provide guidance on best practices, conduct peer code reviews, and champion continuous improvement Requirements Bachelor’s degree in Science, Techn

MongoDB is bolstering its hiring, focusing on creating tools that guide customers in transitioning their applications from relational databases to MongoDB. As businesses evolve their application development frameworks, they're increasingly drawn to the versatility of the document model. The Relational Migrator team, already instrumental in this area, aids developers in making the shift from relational databases to MongoDB. Now, they're broadening their toolkit and are keen on refining code using a mix of AI and traditional text processing. MongoDB is seeking a Software Engineer with solid software engineering skills and a machine learning background. Joining this team, you'll be pivotal in a product engineering group dedicated to helping users navigate code conversion challenges with AI's support. This role will be based out of North America in the PST and MST zones only. The ideal candidate for this role will have 2+ years of professional software development experience in Java or another programming language Experience with generative AI and specifically LLMs is highly desirable Experience with text processing engines such as ANTLR is highly desirable Strong understanding of software engineering, system design, data engineering and/or cloud architecture Have experience with compiler design, code parsing or related areas Familiarity with concepts like abstract syntax trees (AST), lexical analysis, and syntax analysis Curiosity, a positive attitude, and a drive to continue learning Actively engages in emerging trends and research relevant to product features Excellent verbal and written communication skills Position Expectations Collaborate with stakeholders to define and implement a code modernisation strategy, ensuring that transformed code aligns with modern software practices while preserving original functionality Develop and maintain a robust code parser to accurately interpret legacy code structures, converting them into a standardised format like an abstract

MongoDB is bolstering its hiring, focusing on creating tools that guide customers in transitioning their applications from relational databases to MongoDB. As businesses evolve their application development frameworks, they're increasingly drawn to the versatility of the document model. The Relational Migrator team, already instrumental in this area, aids developers in making the shift from relational databases to MongoDB. Now, they're broadening their toolkit and are keen on refining code using a mix of AI and traditional text processing. MongoDB is seeking a Software Engineer with solid software engineering skills and a machine learning background. Joining this team, you'll be pivotal in a product engineering group dedicated to helping users navigate code conversion challenges with AI's support. This role will be based out of North America in the PST and MST zones only. The ideal candidate for this role will have 2+ years of professional software development experience in Java or another programming language Experience with generative AI and specifically LLMs is highly desirable Experience with text processing engines such as ANTLR is highly desirable Strong understanding of software engineering, system design, data engineering and/or cloud architecture Have experience with compiler design, code parsing or related areas Familiarity with concepts like abstract syntax trees (AST), lexical analysis, and syntax analysis Curiosity, a positive attitude, and a drive to continue learning Actively engages in emerging trends and research relevant to product features Excellent verbal and written communication skills Position Expectations Collaborate with stakeholders to define and implement a code modernisation strategy, ensuring that transformed code aligns with modern software practices while preserving original functionality Develop and maintain a robust code parser to accurately interpret legacy code structures, converting them into a standardised format like an abstract

About the job Senior Backend Engineer |100% Remote We are searching for a seasoned Sr Backend Engineer who will be responsible for developing and maintaining our backend systems, ensuring their efficiency, scalability, and reliability. The ideal candidate has a strong background in PHP and Java, with optional experience in Golang and Node.js. You should be well-versed in working with databases such as MongoDB, Redis, and Postgres, and have a solid understanding of cloud technologies, specifically AWS. Responsibilities Design, develop, and maintain backend systems and APIs to support our application's functionality. Collaborate with cross-functional teams, including front-end developers, product managers, and designers, to deliver high-quality solutions. Write clean, scalable, and well-documented code that adheres to industry best practices and coding standards. Perform code reviews and provide constructive feedback to peers to ensure code quality and consistency. Optimize and improve the performance of existing backend systems. Troubleshoot and debug production issues, providing timely resolutions. Stay up-to-date with emerging technologies and industry trends, identifying opportunities for innovation and improvement. Collaborate with DevOps teams to ensure smooth deployment and operation of backend services in the AWS cloud environment. Requirements Bachelor's degree in Computer Science, Engineering, or a related field (or equivalent work experience). 5-10 years of professional experience as a Backend Engineer. Strong proficiency in Java/Golang is a must. Experience with Node js is a plus. In-depth knowledge of database technologies, including MongoDB, Redis, and Postgres. Solid understanding of cloud computing platforms, particularly AWS. Familiarity with containerization technologies such as Docker and orchestration tools like Kubernetes. Proficiency in writing efficient and optimized SQL queries. Experience with version control systems, such as Git. Excellent pr

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. The Data Access team within Infra / Storage builds EaaS (Entities-as-a-Service), Roblox’s large-scale managed OLTP access and management platform powering tens of millions of QPS across thousands of services. EaaS abstracts the complexity of distributed databases and caching systems behind a consistent and productive developer experience, enabling teams across Roblox to safely build and operate stateful systems at massive scale without requiring deep database expertise. The team operates at the intersection of distributed systems engineering, reliability engineering, and platform architecture — solving hard infrastructure problems that directly impact Roblox-wide scale and stability. As a Senior Software Engineer you will work on some of Roblox’s hardest backend infrastructure challenges around scalability, reliability, workload governance, adaptive flow control, and distributed systems. You Will Build and evolve EaaS, Roblox’s managed OLTP access platform powering tens of millions of QPS across hundreds of services. Design infrastructure that abstracts distributed databases and caching systems behind a consistent, safe, and highly productive developer experience. Drive reliability and scal

MongoDB is looking for an outstanding person to join our newly created Forward Deployed Engineering team and take on a key role in our extended R&D organization. Forward Deployed Engineering is linking the work of teams engaged on application modernization roles with our Product and Engineering teams. We are looking to speak to candidates who are based in Dublin or Cork for our hybrid working model. Many organizations have built up large estates of legacy applications. Lack of scalability and resilience, long development times, operating cost, and inability to run on cloud are common issues with these applications. To address these issues, organizations are engaging in large transformational Application Modernisation programs. MongoDB is recognized as the developer data platform of choice for transactional systems that provide the best scalability, resiliency and developer experience in the cloud as well as on premises. Organizations are continuously migrating workloads from these legacy applications to new platforms, often based on microservices, using MongoDB. Such transformations are time intensive and often risky. Tooling based on generative AI promises to accelerate these transformations in a way never seen before. Forward Deployed Engineering is responsible for exploring the possibilities of Generative AI technologies and providing invaluable feedback to MongoDB’s R&D teams to drive future capabilities of MongoDB and the MongoDB ecosystem. Application Modernization Engineers will work alongside project teams that are executing Application Modernisation projects with customers. The successful candidate will be responsible for evaluation, build, and applying tools in modernization projects, facilitating the usage of such tools and processes across the different project teams, identifying opportunities for tooling deployment, selecting potential 3rd party tools, contributing to the development of tooling prototypes and helping to shape t

Who we are At Twilio, we’re shaping the future of communications, all from the comfort of our homes. We deliver innovative solutions to hundreds of thousands of businesses and empower millions of developers worldwide to craft personalized customer experiences. Our dedication to remote-first work , and strong culture of connection and global inclusion means that no matter your location, you’re part of a vibrant team with diverse experiences making a global impact each day. As we continue to revolutionize how the world interacts, we’re acquiring new skills and experiences that make work feel truly rewarding. Your career at Twilio is in your hands. . Hiring and how we work We use Artificial Intelligence (AI) to help make our hiring process efficient. That said, every hiring decision is made by real Twilions! Also, while we are a remote-first company, you may be asked to report in person on an ad-hoc basis for team gatherings, functional off-sites or customer meetings. . See yourself at Twilio Join the team as Twilio’s next Senior Software Engineer. About the job This position is needed to design, build, and optimize the core signalling infrastructure that powers real-time video communications for our customers. You will play a key role in ensuring high performance, reliability, and scalability of our video platform, enabling seamless and secure video experiences. Responsibilities In this role, you’ll: Design, implement, and maintain video signalling protocols and server components for real-time video calls (e.g., WebRTC, SIP, RTCP/RTP) in a highly scalable distributed system. Collaborate with cross-functional distributed teams and various stakeholders to deliver high-performance, low-latency media experiences. Ensure secure transmission and compliance with industry best practices (e.g., end-to-end encryption, privacy standards). Contribute to architectural decisions and code reviews, mentoring junior engineers as needed. Stay current with

About Appier Appier is an AI-native Agentic AI as a Service (AaaS) company that uses artificial intelligence (AI) to power business decision-making. Founded in 2012 with a vision of democratizing AI, Appier’s mission is turning AI into ROI by making software intelligent. Appier now has 17 offices across APAC, Europe and U.S., and is listed on the Tokyo Stock Exchange (Ticker number: 4180). Visit www.appier.com for more information. About the role Appier's Playable Ads team ( https://www.appier.com/en/blog/what-is-playable-ads ) builds AI-powered playable and video ad experiences that drive dramatically higher engagement and conversion for the world's leading apps and games. We're looking for a Senior Backend Developer with deep expertise in distributed systems and modern backend architecture to design and build the scalable, high-performance services behind these experiences — from creative generation pipelines to the infrastructure that brings our ML models to production. You'll work across microservices, messaging systems, data persistence layers, and system performance optimization, while partnering with ML scientists on MLOps workflows to continuously ship and serve new model versions to end users. You'll also collaborate closely with frontend engineers and product managers to deliver seamless, cross-functional outcomes. If you're passionate about building backend systems that operate at scale, thrive in cross-functional teams, and want your code to directly power AI-driven ad experiences reaching millions of users, we'd love to talk. What You'll Work On Architect and develop robust, scalable backend services and APIs using ASP.NET Core, owning sizable projects from system design through production operation. Design efficient database schemas and optimize data access logic across SQL and NoSQL data stores. Implement message-driven communication with high reliability and fault tolerance. Partner with ML scientists to build and maint

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 Join our Retail Trading team and you will be working alongside a high-performing team to deliver comprehensive and timely market information to millions of retail users. You will leverage your expertise to design and build easy-to-use applications with distinguishable precision, speed, and insights. In this role, you’ll also contribute to the evolution of our architectural foundations, ensuring that our solutions remain reliable, scalable, and adaptable in a rapidly evolving market. What You’ll Be Doing Design, develop, and maintain high-quality backend systems for market analysis in a fast-paced, dynamic environment. Collaborate closely with product managers, frontend engineers, and infrastructure teams to deliver scalable and efficient solutions. Continuously improve system reliability, scalability, and maintainability through thoughtful design and engineering best practices. Actively participate in code reviews, architecture design discussion

Backend - Technical Lead About Us: Paytm is India’s largest digital payments and financial services platform, leading the mobile QR revolution. We power millions of businesses and individuals, and we’re building scalable, resilient systems to serve half a billion Indians and beyond. About the Role: 1) As a Technical Lead, you’ll not just write code — you’ll design scalable architectures, coach engineers, and lead technology-first projects. 2) You'll drive backend systems that support 100M+ DAUs, optimize APIs to sub-50ms latencies, and be a champion of engineering excellence. 3) We expect you to actively use AI tools to accelerate architecture design, code reviews, prototyping, and developer productivity. What We're Looking For: 1) 4 to 6 ears of hands-on backend engineering experience — Java/Nodejs. 2) Proven ownership of high-scale distributed systems. Deep knowledge of microservices, messaging systems, caching, storage optimization, and cloud scalability. 3) Clear architectural thinking; you can design systems for billions of transactions, not just millions. 4) An AI-first mindset — you should know how to augment yourself with GPT and other AI coding tools to move 2x faster. 5) Strong leadership skills — mentoring, code reviewing, pushing for engineering best practices. Why You Should Join Us: 1) Massive ownership and real-world system building opportunities. 2) Work with AI, not against it — code smarter, architect smarter, and build smarter. 3) We are a pure tech-driven team inside Paytm — no unnecessary meetings, no bureaucracy. 4) You’ll work on critical platforms, live user-impacting systems, and future-proof engineering. Preferred Qualifications : Bachelor's/Master's Degree in Computer Science or equivalent

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 Service team is the backbone of our exchange's industry-leading trading product, which is utilized by millions of users. We are responsible for the core order and position management systems, enabling a full spectrum of trading products, including manual, automatic, and social trading, as well as brokerage services. Our platform supports diverse financial instruments such as spot, margin, futures, options, and perpetuals. Join our elite Trading Service team as a Senior Staff Software Engineer, where you will be a pivotal technical leader shaping the future of our ultra-low latency, high-throughput trading platform. This is a highly impactful individual contributor role for an exceptional engineer with a deep passion for financial markets and cutting-edge technology. You will own and drive the architectural direction for critical system components, solve the most complex technical challenges across multiple teams, and significantly in

Backend - Technical Lead About Us: Paytm is India’s largest digital payments and financial services platform, leading the mobile QR revolution. We power millions of businesses and individuals, and we’re building scalable, resilient systems to serve half a billion Indians and beyond. Here at Paytm, technology isn't just about keeping up, it's about building the future. We believe the next generation of engineers must not only scale systems to billions but also leverage AI and GPT tools to accelerate innovation About the Role: 1) As a Technical Lead, you’ll not just write code — you’ll design scalable architectures, coach engineers, and lead technology-first projects. 2) You'll drive backend systems that support 100M+ DAUs, optimize APIs to sub-50ms latencies, and be a champion of engineering excellence. 3) We expect you to actively use AI tools to accelerate architecture design, code reviews, prototyping, and developer productivity. What We're Looking For: 1) 4 to 6 years of hands-on backend engineering experience — Java, Spring Boot, AWS.) 2) Proven ownership of high-scale distributed systems. Deep knowledge of microservices, messaging systems, caching, storage optimization, and cloud scalability. 3) Clear architectural thinking; you can design systems for billions of transactions, not just millions. 4) An AI-first mindset — you should know how to augment yourself with GPT and other AI coding tools to move 2x faster. 5) Strong leadership skills — mentoring, code reviewing, pushing for engineering best practices. Why You Should Join Us: 1) Massive ownership and real-world system building opportunities. 2) Work with AI, not against it — code smarter, architect smarter, and build smarter. 3) We are a pure tech-driven team inside Paytm — no unnecessary meetings, no bureaucracy. 4) You’ll work on critical platforms, live user-impacting systems, and future-proof engineering. Ideal Profile 1) Obsessed with system scale, performance, and reliability. 2) Already