Senior Software Engineer (IRL/UK)
Circle is a cutting-edge financial technology company spearheading innovation in the realm of digital monetary transactions. Our forward-thinking technology facilitates the seamless transfer of value across borders in a swift and cost-effective manner. This revolutionary development in the world of finance opens up new realms of possibility for global economic growth and increased accessibility. Through our infrastructure and groundbreaking projects like USDC, we empower businesses, institutions, and developers to capitalize on this transformative shift in the intersection of money and technology.
Company Culture:
At Circle, we prioritize transparency and reliability in all our endeavors. As we expand our presence across diverse geographic regions, we uphold values centered on speed, efficiency, and excellence. Our team embodies key values such as Multistakeholder approach, Mindfulness, Drive for Excellence, and High Integrity. In a remote work environment, our employees are dedicated to continuous growth and collaborative success. By fostering a flexible and inclusive workplace, we encourage innovative thinking and ensure every individual feels a sense of ownership and contribution.
Key Responsibilities:
The Senior Software Engineer plays a crucial role in enhancing Circle's in-house blockchain ecosystem to support widespread digital tokenization. Duties include analyzing, optimizing, and extending existing systems, developing scalable microservices to facilitate secure API interactions across various blockchain and traditional banking protocols, partnering with cross-functional teams to shape features, and ensuring system reliability. Other responsibilities involve troubleshooting system issues, creating developer-friendly APIs for payment system integration, and collaborating with industry-leading organizations for seamless service delivery.
Job Requirements:
To thrive in this role, candidates must possess a minimum of 4 years of professional experience in software development using object-oriented languages, preferably Java. A degree in Computer Science or equivalent field, experience in team leadership, proficiency in payment system operations, RESTful API design understanding, familiarity with Cloud Services, and skill in SQL database development are essential. Additionally, strong focus on coding standards, an inclination towards continuous improvement, effective communication, and the ability to work autonomously in a dynamic environment are required attributes for success.
We are committed to fostering a diverse and inclusive work environment and do not discriminate based on factors like race, religion, gender, or age. Join us at Circle as we embark on an exciting journey towards transforming the global financial landscape.
AI-Native Full-Stack Product Engineer
We are an AI & Blockchain company building the financial infrastructure for the AI age. We have customers in 19 countries, and our team is an international mix of remote talents with two core locations in Singapore and Dubai.
We raised $2.8M in funding and are expanding our team, with new products across SaaS and retail. By joining now, you’ll have the unique opportunity to work directly with founders who have made multiple exits, and build the future of AI and finance.
About You
You are a full-stack product engineer who can turn ideas into products from 0 to 1, using modern agentic coding tools without losing engineering judgment. This is not a simple vibe-coding role. You need to know how to code, reason about systems, identify poor abstractions, avoid AI-generated slop, and ship software that is readable, maintainable, and useful. You should be able to sit with a product idea, identify the core user flow, design the first version, build the front end, wire up the back end, leverage AI tools aggressively, and still have the engineering judgment to know when the code is wrong.
Your Profile
Full-stack engineer with real product taste.
AI-native, but not AI-dependent.
Comfortable shipping across front end, back end, database, infra, and third-party APIs.
Able to use coding agents deeply while maintaining control over architecture and quality.
Good at detecting slop: messy code, fake abstractions, weak tests, security gaps, bad UX, and hidden complexity.
Independent, fast, curious, and comfortable with ambiguity.
Your Work
Build products and tools from scratch.
Use AI coding tools to materially increase shipping speed.
Work across React/Next.js, Node/Python, databases, APIs, authentication, cloud platforms, and similar technologies.
Turn product ideas and UX concepts into useful software with minimal direction.
Chief Technology Officer (CTO) / Senior Full-Stack Developer (Web3)
We are building a next-generation Web3 social platform designed to redefine how digital communities connect, collaborate, and grow.
Backed by years of experience within the cryptocurrency, blockchain, and digital asset ecosystem, our team has developed deep insights into how founders, developers, investors, creators, and communities interact. This understanding inspired us to create a platform that goes beyond financial applications and focuses on empowering meaningful social engagement.
Our mission is to build a transparent, community-driven social network where users can share ideas, collaborate on projects, discover opportunities, and create lasting relationships. We believe the next evolution of social media will be powered by decentralized technologies while maintaining an exceptional user experience, simplicity, and long-term sustainability.
We are seeking an experienced Chief Technology Officer (CTO) or Senior Full-Stack Developer who is passionate about Web3 and capable of leading the technical vision, architecture, and execution of our platform from the ground up.
Responsibilities
Lead the technical strategy and product architecture.
Design and build scalable backend systems and modern frontend applications.
Develop high-performance APIs and real-time features.
Integrate blockchain technologies, wallets, and Web3 authentication where appropriate.
Build secure, reliable, and maintainable infrastructure.
Collaborate closely with product, design, and leadership teams.
Establish engineering best practices, code quality standards, and development workflows.
Mentor engineers and help grow the technical organization.
Evaluate emerging technologies and implement solutions that improve scalability, security, and user experience.
Requirements
5+ years of professional software development experience.
Strong experience with modern JavaScript/TypeScript ecosystems.
Experience with React, Next.js, Node.js, or similar technologies.
Solid understanding of system architecture, cloud infrastructure, databases, and API design.
Experience building scalable consumer-facing products.
Familiarity with blockchain technologies, Web3 infrastructure, wallets, smart contracts, or decentralized applications.
Strong knowledge of security best practices and application performance optimization.
Excellent problem-solving and communication skills.
Ability to work independently in a fast-paced startup environment.
Preferred Qualifications
Experience building Web3 or crypto products.
Understanding of decentralized identity, token ecosystems, or on-chain social applications.
Experience leading engineering teams or serving in a technical leadership role.
Background in DevOps, CI/CD, Docker, Kubernetes, or cloud platforms such as AWS or GCP.
Experience with real-time messaging, social platforms, or community products.
What We Offer
Competitive full-time compensation.
Opportunity to build a product from an early stage with significant technical ownership.
Flexible and remote-friendly work environment.
Collaborative team focused on innovation and long-term impact.
Work on cutting-edge Web3 technologies and help shape the future of digital communities.
Opportunity for career growth and leadership as the platform scales.
If you are excited about building the next generation of Web3 social experiences and want to make a meaningful impact from the earliest stages, we'd love to hear from you.
Backend Engineer with hands-on blockchain experience
Senior Blockchain Engineer (Cosmos SDK & IBC)
Expectations:
Design custom modules (x/staking, x/rewards, x/merkl)
Implement IBC light clients and relayers
Optimize block time and state pruning
Write comprehensive unit & integration tests (Go test)
Build CLI tools for validators and delegators
Monitor node health and network upgrades
Collaborate with the research team on MEV-resistant ordering
Maintain chain upgrades (v1 → v2) with migration scripts
Write technical documentation for external validators
Nice to have:
Experience with Avalanche Subnets or Polkadot Substrate
Knowledge of HSM and key management
Open-source contributions to Cosmos SDK or related repos
Chinese+English language proficiency
Senior Mobile application developer
But specially, candidate should be native in English.
Team communication is very important.
Please bid US only
Thank you