Principal Software Engineer - Blockchain Wallet Infrastructure

Location: Remote - Location: European Union (remote-first, office optional) Paris/ France is always preferred. Or as close as possible.

Compensation: $145K - $240K

Join a stellar team of leaders and experts building the backbone of blockchain wallet infrastructure for the next financial era, specializing in cryptography, security, and distributed systems. Our client is seeking a Principal Software Engineer to lead the design, development, and scaling of their core backend systems. This is a high-impact, leadership role focused on making key architectural decisions and ensuring their platform is fast, resilient, and secure under the high-stakes demands of financial workflows.

You will own mission-critical projects end-to-end, acting as a technical leader who drives engineering standards and the long-term vision. This role involves deep technical execution alongside strategic collaboration with product, security, and executive leadership to align technical roadmap with business goals.

Responsibilities:

Platform Engineer (Backend)

Location: London, New York

Onsite | Full-time

Compensation: Competitive

Our client is an elite team of builders and a high-growth software development company at the forefront of the fintech and digital asset sectors. The organization is a primary contributor to one of the largest and most active crypto social networks globally, a platform that has generated over $600 million in revenue since early 2024. Operating at the intersection of high-scale social coordination and decentralized finance, the firm is dedicated to redefining the infrastructure of the future.

The organization is seeking a Platform Engineer to join a high-performance environment characterized by talent density and rapid execution. This role is critical in ensuring the security, scalability, and integrity of a platform attracting significant global attention. The successful candidate will bridge the gap between backend engineering and infrastructure security, implementing robust controls across a complex cloud and blockchain ecosystem.

Key Responsibilities

Backend Software Engineer - Payments & Digital Money

Location: New York (Hybrid)

Compensation: $150K - $180K

We are a lean and mighty team of passionate builders, funded by top investors in fintech and crypto, focused on empowering the next generation of money and financial products globally. We are seeking a Backend Software Engineer to join us at the cutting edge intersection of real-world payments and digital money, where you will deliver massive impact within a small, quickly growing company.

You will be a critical part of defining our technical and product roadmap, contributing directly to our core backend infrastructure. This role involves rapid feature shipping, large-scale system scaling, and integrating with diverse third-party services and smart contracts across multiple chains. You will have the freedom to explore ideas, impact the company's vision, and grow into the role that best aligns with your personal goals.

What You'll Do:

Staff Backend Engineer

Location: London or New York City

Onsite | Full-time

Compensation: competitive

Our client is a high-performance technology development firm responsible for building and operating the infrastructure behind the world’s largest and most active digital asset launchpads. Processing approximately $1B in daily volume, the platform operates at the bleeding edge of crypto scale, requiring systems designed for ultra-low latency, high throughput, and constant high-concurrency load.

The organization is seeking a Lead Backend Engineer to own the most complex technical challenges across the system. This is a high-stakes, high-impact role within an intense, in-person environment. The team is composed of high-agency builders who value speed, immediate impact, and rigorous engineering judgment. This position is ideal for an engineer who thrives under pressure and is motivated by the opportunity to solve ambiguous, cross-cutting problems that others cannot.

Key Responsibilities

Overview 

We’re looking for a Mobile Engineer passionate about creating high-quality, user-focused applications that connect people through performance, movement, and data especially within sports and wearable technology ecosystems. 

Job Overview 

You will design, build, and maintain React Native applications for both Android and iOS. You’ll develop tools and experiences that connect users through sports and activity platforms, integrating with wearables and real-time data systems to deliver seamless tracking, analytics, and engagement. 

You’ll collaborate closely with backend developers, product managers, and designers to turn complex data and operational flows into intuitive, reliable mobile experiences. 

Key Responsibilities 

We’re looking for a remote Full Stack Developer based in Jordan or Egypt passionate about modern architectures, seamless user experiences, and scalable backend systems to join our growing engineering team.  

Job Overview  

As a Full Stack Developer, you will design and build serverless and microservice-based applications leveraging AWS technologies. You’ll work across the stack from creating intuitive React interfaces to developing scalable Node.js APIs ensuring performance, reliability, and maintainability across our platforms.  

Key Responsibilities  

• Design and develop serverless and microservice architectures using AWS Lambda, API Gateway, and related services.  

• Build responsive, high-quality front-end interfaces using React.  

• Develop and maintain robust back-end APIs using Node.js.  

• Collaborate with cross-functional teams to deliver scalable, high-performance solutions.  

• Implement and maintain CI/CD pipelines for smooth deployment and updates.  

• Ensure system reliability, security, and scalability through clean and efficient code.  

Qualifications  

Senior Infrastructure Engineer - Blockchain Wallet Backbone

Location: Remote - United States

Compensation: $180K - $300K

Join a stellar team of leaders and experts in blockchain technology, cryptography, and security. Our client is seeking a Senior Infrastructure Engineer to design, operate, and scale systems at the intersection of blockchain, cybersecurity, and distributed infrastructure, preparing them to meet the demands of a trillion-dollar industry.

This role goes beyond maintenance—you will be an architect, automator, and security expert. You will embed best-in-class DevOps and SRE practices into their workflows, ensuring their services are highly reliable, secure, and cost-efficient. You will collaborate across engineering, product, and security to translate complex requirements into scalable infrastructure.

Key Responsibilities:

Full Stack Engineer - Payments & FinTech Web Applications

Location: Remote - Based in EST or GMT+1

Compensation: $120K - $150K

We are a high-growth technology company building a robust FinTech and payments platform. We are seeking an experienced Full Stack Engineer with strong product sense and deep technical expertise to design and build the secure, scalable, and high-performing web applications that power our platform. This role requires translating complex backend financial systems into intuitive, reliable user experiences.

You will own the development lifecycle of web applications from design through release, working across the full stack with an emphasis on the frontend user experience. You will collaborate closely with backend teams, ensuring that all features prioritize performance, security, and scalability. You will be expected to treat UI components and APIs as products, maintaining high standards for code quality and architectural clarity.

What You'll Do:

Senior Full Stack Engineer - (Platform)

Location: Remote - Preference for NYC - Or Remote USA or Tel Aviv (classed as Europe) to work EST hours

Remote | Full-time

Compensation: $144K - $164K

Our client is a pioneer in automated, on-chain economic security, providing a sophisticated system that enables crypto protocols to optimize risk management and capital efficiency. By analyzing protocol mechanics and scenario implications through world-class custom EVM simulations, the platform provides actionable insights trusted by leading decentralized finance (DeFi) protocols to manage and secure billions of dollars in assets.

The organization is seeking a proactive and results-driven Senior Full Stack Engineer to join the team. Reporting directly to the Platform Team Lead, the successful candidate will play a critical role in building data-driven dashboards and tools to support complex risk analysis. This role involves close collaboration with research and protocol teams to deliver high-quality frontend and backend components that power essential security insights.

Key Responsibilities

Senior/Lead Backend Engineer - FinTech & Crypto Innovation

Location: Remote - Fully remote across Europe - they can do B2B or hire through EoR.

Compensation: $120K - $140K

We are seeking a Senior/Lead Backend Engineer to help us revolutionize the FinTech and crypto industry. This is a fast-paced environment where you will solve complex banking and crypto problems, translating them into elegant, efficient, and resilient architectural solutions. Your ability to deliver high-quality code makes you a pillar of our engineering team.

You will work directly with the product team, owning the design, development, and deployment of mission-critical services that power our next-generation financial platform. Your focus will be on building highly scalable and resilient backend systems that handle core banking functions, blockchain integrations, and serve data to our applications.

What You'll Be Working On: