Staff Software Security Engineer - Web 3.0 (f/m)
Paris, France
Full time
Office
Compensation is not specified
Role
Security Engineer
Description
We are a pioneering company that is driven by a mission that transcends mere business objectives. Our goal is to establish and safeguard digital ownership in a dynamic world, facilitating true freedom. Embracing innovation, we constantly push the boundaries of what is achievable by merging excellence and pragmatism with ambition and certainty. Within our innovative environment, you will lead the way in shaping the rules of emerging technologies to create products that redefine security in the digital era.
Established in 2014, our organization, Ledger, serves as a global platform for digital assets and Web3 technology. A significant portion of the world's crypto assets are safeguarded through our Ledger Nanos. With our headquarters located in Paris and Vierzon, and additional offices in the UK, the US, Switzerland, and Singapore, our team of over 700 professionals is dedicated to producing a range of products and services. These offerings enable individuals and businesses to securely buy, store, exchange, enhance, and manage cryptocurrency assets. Among our products, the Ledger hardware wallets line has already amassed over 7 million units sold across 200 countries.
The Donjon team leads all product security initiatives at Ledger. As a staff security engineer, your main responsibility will include testing our products and their interconnected ecosystem rigorously to uphold and enhance our standing as an industry leader.
Role Overview
- Explore state-of-the-art offensive security strategies, create tools and exploits for our products, and develop solutions to address identified vulnerabilities,
- Conduct security assessments of Web3 interactions, encompassing smart contracts, secure signing mechanisms, and dApp integrations.
- Collaborate closely with the Product team to outline secure user interactions, lessening risks arising from malicious Web3 interactions.
- Showcase your findings at academic conferences and hacking events worldwide.
Desired Qualifications
- Extensive background in Web3 security.
- Proficiency in DeFi protocols and dApps development.
- Basic understanding of financial services.
- Self-motivated with a keen aptitude for adapting to evolving security landscapes.
Required Technical Skills
- Proficiency in Solidity and Rust, focusing specifically on secure programming in these languages.
- Knowledge in reverse engineering and binary analysis.
- Strong grasp of exploitation techniques and countermeasures against them.
- Substantial experience with static analysis tools and formal verification.
- Ability to devise and document methodologies, protocols, and standards.
Perks & Benefits
- Stock options allow employees to share in the company's success.
- Adopting a hybrid work policy that provides flexibility.
- Annual company outings, frequent social gatherings, as well as complimentary snacks and beverages.
- Comprehensive healthcare coverage including medical, dental, and vision care.
- Personal development opportunities, coaching, and fitness programs with dedicated partners.
- Generous vacation package, with five weeks of paid leave per year accompanied by national holidays and rest & relaxation (RTT) days.
- Access to high-performance office equipment and technology, including Apple products.
- Transportation reimbursement program.
- Employee discounts across all product offerings.
Ledger is committed to ensuring fairness for all candidates during the recruitment process, regardless of gender, ethnic background, religion, sexual orientation, social status, disability, or age.
Skills Required
Ledger
Website
www.ledger.comCompany size
Not specified
Location
United States
Description
Ledger is a leader in security and infrastructure solutions for cryptocurrencies and blockchain applications. We are constantly looking for innovative, talented people to join our team.
Rivalz Network
AI Researcher (mid-level)
Full time
Remote
Rivalz Network
Rivalz Network’s infrastructure abstracts the complexities of connecting AI services and agents to various real-world resources. By orchestrating resource-backed agents, providing a decentralized data layer for secure processing and retrieval, enabling verifiable requests through an AI oracle, mapping both identity and resources seamlessly, and offering an AI x Web3 platform for fast application publishing and monetization, Rivalz empowers teams to bridge digital and physical ecosystems. Our ultimate goal is to unlock the full potential of an agent-centric future, enabling developers and no-code builders alike to harness AI-driven solutions with ease.
Working at Rivalz
We embrace a flexible, globally distributed environment that allows our team members to work from where they’re most comfortable—whether that’s at home or on the move. We leverage virtual collaboration and remote-friendly policies, enabling you to balance your personal life, family commitments, and professional goals. Wherever you are, you’ll be an integral part of our team which is shaping the future of AI, blockchain, and decentralized infrastructures. Join Rivalz’s forward-thinking AI Research team to push machine learning and agent-centric design, delivering impactful AI-Web3 solutions that empower innovators worldwide.
About the Role: AI Researcher (Mid-Level)
As a Mid-Level AI Researcher at Rivalz, you will play a key role in advancing our AI capabilities for seamless integration with real-world resources. You’ll spearhead novel research initiatives, publish findings, and architect solutions that drive our decentralized, agent-centric vision. If you’re eager to explore cutting-edge machine learning, deep learning, and blockchain, while seeing your work rapidly deployed in production, this is the perfect opportunity for you.
Key Responsibilities
Innovate & Research: Conduct advanced AI research in ML and DL to address complex challenges.
Design & Prototype: Architect and evaluate novel AI models for decentralized infrastructures.
Collaboration & Deployment: Work with cross-functional teams to develop production-ready AI solutions.
Open-Source & Community: Maintain a strong GitHub presence and engage with the broader AI/Web3 community.
Thought Leadership: Stay current with emerging AI trends to continually refine Rivalz’s infrastructure.
Real-World Integration: Expand AI’s reach into both digital and physical ecosystems for seamless interoperability.
Qualifications
Educational Background: Bachelor’s in Computer Science or related field (Master’s/PhD preferred).
Technical Expertise: Proficiency in Python, ML frameworks, and experience with LLMs/generative AI.
Blockchain Familiarity: Exposure to decentralized systems and their intersection with AI is a bonus.
Research & Publication: Track record in AI research, open-source contributions, or academic publications.
Collaboration & Communication: Strong interpersonal skills for distributed team coordination.
Adaptability & Problem-Solving: Ability to navigate evolving technologies with iterative, data-driven approaches.
Join us at Rivalz and be part of a pioneering team that’s redefining how AI agents interact with the world. Contribute your expertise, collaborate across disciplines, and help shape the agent-centric future.
How to Apply:
Submit your cover letter and resume at humaira@rivalz.ai
Rivalz Network’s infrastructure abstracts the complexities of connecting AI services and agents to various real-world resources. By orchestrating resource-backed agents, providing a decentralized data layer for secure processing and retrieval, enabling verifiable requests through an AI oracle, mapping both identity and resources seamlessly, and offering an AI x Web3 platform for fast application publishing and monetization, Rivalz empowers teams to bridge digital and physical ecosystems. Our ultimate goal is to unlock the full potential of an agent-centric future, enabling developers and no-code builders alike to harness AI-driven solutions with ease.
Working at Rivalz
We embrace a flexible, globally distributed environment that allows our team members to work from where they’re most comfortable—whether that’s at home or on the move. We leverage virtual collaboration and remote-friendly policies, enabling you to balance your personal life, family commitments, and professional goals. Wherever you are, you’ll be an integral part of our team which is shaping the future of AI, blockchain, and decentralized infrastructures. Join Rivalz’s forward-thinking AI Research team to push machine learning and agent-centric design, delivering impactful AI-Web3 solutions that empower innovators worldwide.
About the Role: AI Researcher (Mid-Level)
As a Mid-Level AI Researcher at Rivalz, you will play a key role in advancing our AI capabilities for seamless integration with real-world resources. You’ll spearhead novel research initiatives, publish findings, and architect solutions that drive our decentralized, agent-centric vision. If you’re eager to explore cutting-edge machine learning, deep learning, and blockchain, while seeing your work rapidly deployed in production, this is the perfect opportunity for you.
Key Responsibilities
Innovate & Research: Conduct advanced AI research in ML and DL to address complex challenges.
Design & Prototype: Architect and evaluate novel AI models for decentralized infrastructures.
Collaboration & Deployment: Work with cross-functional teams to develop production-ready AI solutions.
Open-Source & Community: Maintain a strong GitHub presence and engage with the broader AI/Web3 community.
Thought Leadership: Stay current with emerging AI trends to continually refine Rivalz’s infrastructure.
Real-World Integration: Expand AI’s reach into both digital and physical ecosystems for seamless interoperability.
Qualifications
Educational Background: Bachelor’s in Computer Science or related field (Master’s/PhD preferred).
Technical Expertise: Proficiency in Python, ML frameworks, and experience with LLMs/generative AI.
Blockchain Familiarity: Exposure to decentralized systems and their intersection with AI is a bonus.
Research & Publication: Track record in AI research, open-source contributions, or academic publications.
Collaboration & Communication: Strong interpersonal skills for distributed team coordination.
Adaptability & Problem-Solving: Ability to navigate evolving technologies with iterative, data-driven approaches.
Join us at Rivalz and be part of a pioneering team that’s redefining how AI agents interact with the world. Contribute your expertise, collaborate across disciplines, and help shape the agent-centric future.
How to Apply:
Submit your cover letter and resume at humaira@rivalz.ai
Jack Morty
Junior Recruiter (Startup)
Part time
Remote
Job Title: Junior Recruiter (Startup)
📌 Responsibilities:
Sourcing candidates for various roles (IT, marketing, sales, etc.).
Conducting initial screenings and interviews.
Managing candidate databases and maintaining communication throughout the hiring process.
Posting job openings on different platforms and social media.
Collaborating with department heads to identify hiring needs.
📌 Requirements:
6+ months of experience in recruitment or a strong desire to learn.
Understanding of sourcing techniques and candidate search methods.
Proficiency in job boards, and social media recruitment.
Ability to conduct interviews and assess candidates effectively.
Strong communication and organizational skills.
English at an Intermediate+ level (preferred).
📌 What We Offer:
Flexible schedule (remote).
Opportunity to grow in a dynamic startup environment.
Training and mentorship from the team.
Competitive salary.
📩 Interested? Send us your resume! 🚀
📌 Responsibilities:
Sourcing candidates for various roles (IT, marketing, sales, etc.).
Conducting initial screenings and interviews.
Managing candidate databases and maintaining communication throughout the hiring process.
Posting job openings on different platforms and social media.
Collaborating with department heads to identify hiring needs.
📌 Requirements:
6+ months of experience in recruitment or a strong desire to learn.
Understanding of sourcing techniques and candidate search methods.
Proficiency in job boards, and social media recruitment.
Ability to conduct interviews and assess candidates effectively.
Strong communication and organizational skills.
English at an Intermediate+ level (preferred).
📌 What We Offer:
Flexible schedule (remote).
Opportunity to grow in a dynamic startup environment.
Training and mentorship from the team.
Competitive salary.
📩 Interested? Send us your resume! 🚀
Payment in Crypto
Cy Ward
Full Stack Blockchain Developer
Frisco, USA
Frisco, USA
Full time
Remote
About BlockBlackHole:BlockBlackHole is a startup company founded in 2024, specializing in blockchain-based solutions and consulting services. Our core expertise lies in leveraging the power of blockchain technology to drive innovation and transformation across various industries, including FinTech, E-commerce, Trading, Healthcare, and Logistics.As a leading blockchain consulting company, we provide our clients with a wide range of services, including Blockchain Development, Data Analytics, Software Development, and Cloud Computing. Our team of talented professionals is dedicated to staying at the forefront of blockchain trends and delivering exceptional results that help our clients achieve their business goals.At BlockBlackHole, we are committed to fostering a collaborative and dynamic work environment that encourages innovation and personal development. We offer competitive compensation packages and opportunities for career advancement, making us an attractive destination for ambitious and skilled professionals who share our passion for blockchain technology.If you are excited about the potential of blockchain and eager to be part of a dynamic startup that is redefining the way businesses operate, we invite you to explore the exciting opportunities at BlockBlackHole.Job Description:As a Senior Full Stack JavaScript Developer with Blockchain Experience, you will play a crucial role in developing cutting-edge blockchain-powered applications and solutions for our clients. You will be responsible for leading the development of both client-side and server-side functionalities, ensuring seamless integration and a delightful user experience across the full stack.Key Responsibilities:- Design and implement user interfaces and server-side logic that interact with the backend systems.- Collaborate with backend developers to integrate front-end and back-end systems, ensuring smooth data flow and functionality.- Optimize web applications for performance and scalability, leveraging your expertise in modern JavaScript frameworks and tools.- Write comprehensive tests and documentation for both client-side and server-side code, ensuring maintainability and reliability.- Participate in code reviews and provide constructive feedback to team members, contributing to the overall quality and development process.- Stay up-to-date with the latest trends and technologies in the blockchain and JavaScript ecosystems, and proactively share your knowledge with the team.Key Requirements:- 5 years of professional software development experience- 2 years of experience in the EVM ecosystem- 1-2 years of professional Rust experience and solidity experience- 3-4 years of professional TypeScript experience and Typescript libraries (Reactjs, Nextjs, Nodejs, Express.js)- 3-4 years of professional experiences about the SQL database (MySQL, PostgreSQL)- Familiarity with Rust and Typescript Ethereum libraries (ethers, alloy, foundry, subgraph)- Entrepreneurial, self-motivated, and driven- Strong work ethic and team playerBenefits:- Competitive salary range of $75,000 to $85,000 USD annually, depending on experience and qualifications.- Comprehensive benefits program, including health insurance, retirement plans, and paid time off.- Flexible and remote work environment, allowing you to maintain a healthy work-life balance.- Opportunity to work at the intersection of blockchain and cutting-edge technologies, shaping the future of decentralized applications.- Professional development and growth opportunities, including access to industry events and conferences.- Be part of a dynamic and innovative team that is passionate about blockchain and its transformative potential.If you meet the qualifications and are excited about the prospect of joining our team, we encourage you to apply. Together, let's push the boundaries of what's possible in the blockchain space and create innovative solutions that will redefine the way businesses operate.
Everyvote
Backend Developer
New York, USA
New York, USA
Full time
Remote
About Us:
GP Vote is an innovative startup dedicated to transforming the democratic process through a cutting-edge voting platform integrated with blockchain technology. Our mission is to empower individuals to voice their opinions and shape collective decisions in a secure and transparent environment. We believe that every voice matters, and our platform fosters inclusivity by allowing users to propose titles and suggestions.
We are seeking a talented Frontend Developer with a strong background in React and TypeScript. The ideal candidate will have experience in Web3 and blockchain technologies, enabling them to contribute to our mission of delivering high-quality digital products.
Key Responsibilities:
Lead the migration of our backend systems from Express.js to ASP.NET.
Design, develop, and maintain scalable and secure backend services.
Collaborate with front-end developers to integrate user-facing elements using server-side logic.
Implement data storage solutions and ensure data integrity.
Develop and maintain APIs for mobile and web applications.
Optimize applications for maximum speed and scalability.
Monitor and troubleshoot issues in the production environment.
Stay updated with emerging technologies and trends in backend development, Web3, and Blockchain.
Required Qualifications:
Proven experience as a Backend Developer or similar role.
Strong proficiency in ASP.NET and C#.
Deep knowledge of backend development principles and best practices.
Proficient in database management (SQL, NoSQL).
Understanding of RESTful APIs and microservices architecture.
Experience with version control systems (e.g., Git).
Preferred Qualifications:
Experience with Web3 technologies (e.g., Ethereum, smart contracts).
Familiarity with Blockchain concepts and decentralized applications (dApps).
Knowledge of containerization technologies (Docker, Kubernetes).
Familiarity with CI/CD pipelines and DevOps practices.
Understanding of security best practices in backend development.
Benefits:
Competitive salary and performance-based bonuses.
Flexible working hours and remote work options.
Generous vacation policy and paid time off.
Health, dental, and vision insurance.
Professional development opportunities and access to online courses.
Collaborative and inclusive company culture.
Opportunities to work on cutting-edge technology in the Web3 and Blockchain space.
Team-building activities and company retreats.
How to Apply:
If you are excited about the opportunity to work with a forward-thinking company and have the skills we’re looking for, please send your resume and a cover letter to larry@everyvote.xyz.
Join us in shaping the future of voting technology!
GP Vote is an innovative startup dedicated to transforming the democratic process through a cutting-edge voting platform integrated with blockchain technology. Our mission is to empower individuals to voice their opinions and shape collective decisions in a secure and transparent environment. We believe that every voice matters, and our platform fosters inclusivity by allowing users to propose titles and suggestions.
We are seeking a talented Frontend Developer with a strong background in React and TypeScript. The ideal candidate will have experience in Web3 and blockchain technologies, enabling them to contribute to our mission of delivering high-quality digital products.
Key Responsibilities:
Lead the migration of our backend systems from Express.js to ASP.NET.
Design, develop, and maintain scalable and secure backend services.
Collaborate with front-end developers to integrate user-facing elements using server-side logic.
Implement data storage solutions and ensure data integrity.
Develop and maintain APIs for mobile and web applications.
Optimize applications for maximum speed and scalability.
Monitor and troubleshoot issues in the production environment.
Stay updated with emerging technologies and trends in backend development, Web3, and Blockchain.
Required Qualifications:
Proven experience as a Backend Developer or similar role.
Strong proficiency in ASP.NET and C#.
Deep knowledge of backend development principles and best practices.
Proficient in database management (SQL, NoSQL).
Understanding of RESTful APIs and microservices architecture.
Experience with version control systems (e.g., Git).
Preferred Qualifications:
Experience with Web3 technologies (e.g., Ethereum, smart contracts).
Familiarity with Blockchain concepts and decentralized applications (dApps).
Knowledge of containerization technologies (Docker, Kubernetes).
Familiarity with CI/CD pipelines and DevOps practices.
Understanding of security best practices in backend development.
Benefits:
Competitive salary and performance-based bonuses.
Flexible working hours and remote work options.
Generous vacation policy and paid time off.
Health, dental, and vision insurance.
Professional development opportunities and access to online courses.
Collaborative and inclusive company culture.
Opportunities to work on cutting-edge technology in the Web3 and Blockchain space.
Team-building activities and company retreats.
How to Apply:
If you are excited about the opportunity to work with a forward-thinking company and have the skills we’re looking for, please send your resume and a cover letter to larry@everyvote.xyz.
Join us in shaping the future of voting technology!
Payment in Crypto
DynamicX
Full Stack Engineer
Baiern, Germany
Baiern, Germany
Full time
Remote
About Us
At DynamicX, we're revolutionizing the way sports enthusiasts invest in their passions. Founded by Nicolas Weiner, Tristan Reinthaler, and Gerd Weiner, our innovative platform merges the excitement of sports with cutting-edge financial technology.
Our mission is to empower sports fans to turn their enthusiasm into smart investments, transforming the traditional sports industry landscape. We believe that by combining sports enthusiasm with strategic financial markets, we can create new opportunities for both fans and athletes alike.
Our journey began with a simple idea: what if sports fans could invest in the very athletes and teams they cheer for? This sparked a movement to democratize access to sports investment and create a more engaging, interactive experience for sports enthusiasts worldwide.
At DynamicX, we're committed to innovation, transparency, and community engagement. Our team of passionate technologists, financial experts, and sports enthusiasts works tirelessly to develop cutting-edge solutions that bridge the gap between sports enthusiasm and smart investing.
Join us in shaping the future of sports investment and turning your passion into a career-defining opportunity.
Job Summary
We're looking for a talented Full Stack Engineer who excels in creating robust, scalable, and efficient web applications. You will play a crucial role in developing and maintaining our core platform, working closely with our cross-functional team to deliver high-quality features and improvements. Your expertise in both front-end and back-end technologies will be invaluable in shaping the future of sports investment.
Responsibilities
Design, develop, test, and deploy full-stack web applications using modern technologies
Collaborate with product managers, designers, and other engineers to understand requirements and create solutions
Implement scalable backend services using Node.js, Express, or similar frameworks
Develop responsive and performant front-end interfaces using React, Vue.js, or similar libraries
Integrate third-party APIs and services effectively
Optimize application performance and maintain high code quality standards
Participate in code reviews and contribute to improving team processes
Troubleshoot production issues and implement bug fixes promptly
Stay up-to-date with industry trends and emerging technologies
Requirements
Bachelor's degree in Computer Science or related field (or equivalent experience)
Minimum 3 years of experience in full-stack development
Proficiency in JavaScript (ES6+) and TypeScript
Experience with modern front-end frameworks (React, Vue.js, or similar)
Strong understanding of backend technologies (Node.js, Express, etc.)
Familiarity with databases (MongoDB, MySQL, etc.) and ORM tools
Knowledge of RESTful APIs and GraphQL
Experience with cloud platforms (AWS, Azure, or Google Cloud)
Version control experience with Git
Strong problem-solving skills and attention to detail
Excellent communication and teamwork abilities
Preferred Qualifications
Experience with blockchain technologies
Knowledge of sports-related APIs or platforms
Familiarity with cryptocurrency trading systems
Experience with automated trading systems
Understanding of tokenization concepts
Certification in cloud computing or DevOps
What We Offer
Competitive salary
Comprehensive health insurance package
Flexible hybrid remote work arrangement
Generous PTO policy (20 days annual leave + 10 paid holidays)
Professional development opportunities
Stock options in a growing startup
Access to cutting-edge technologies and tools
Collaborative and dynamic work environment
Opportunities for career growth and advancement
At DynamicX, we're revolutionizing the way sports enthusiasts invest in their passions. Founded by Nicolas Weiner, Tristan Reinthaler, and Gerd Weiner, our innovative platform merges the excitement of sports with cutting-edge financial technology.
Our mission is to empower sports fans to turn their enthusiasm into smart investments, transforming the traditional sports industry landscape. We believe that by combining sports enthusiasm with strategic financial markets, we can create new opportunities for both fans and athletes alike.
Our journey began with a simple idea: what if sports fans could invest in the very athletes and teams they cheer for? This sparked a movement to democratize access to sports investment and create a more engaging, interactive experience for sports enthusiasts worldwide.
At DynamicX, we're committed to innovation, transparency, and community engagement. Our team of passionate technologists, financial experts, and sports enthusiasts works tirelessly to develop cutting-edge solutions that bridge the gap between sports enthusiasm and smart investing.
Join us in shaping the future of sports investment and turning your passion into a career-defining opportunity.
Job Summary
We're looking for a talented Full Stack Engineer who excels in creating robust, scalable, and efficient web applications. You will play a crucial role in developing and maintaining our core platform, working closely with our cross-functional team to deliver high-quality features and improvements. Your expertise in both front-end and back-end technologies will be invaluable in shaping the future of sports investment.
Responsibilities
Design, develop, test, and deploy full-stack web applications using modern technologies
Collaborate with product managers, designers, and other engineers to understand requirements and create solutions
Implement scalable backend services using Node.js, Express, or similar frameworks
Develop responsive and performant front-end interfaces using React, Vue.js, or similar libraries
Integrate third-party APIs and services effectively
Optimize application performance and maintain high code quality standards
Participate in code reviews and contribute to improving team processes
Troubleshoot production issues and implement bug fixes promptly
Stay up-to-date with industry trends and emerging technologies
Requirements
Bachelor's degree in Computer Science or related field (or equivalent experience)
Minimum 3 years of experience in full-stack development
Proficiency in JavaScript (ES6+) and TypeScript
Experience with modern front-end frameworks (React, Vue.js, or similar)
Strong understanding of backend technologies (Node.js, Express, etc.)
Familiarity with databases (MongoDB, MySQL, etc.) and ORM tools
Knowledge of RESTful APIs and GraphQL
Experience with cloud platforms (AWS, Azure, or Google Cloud)
Version control experience with Git
Strong problem-solving skills and attention to detail
Excellent communication and teamwork abilities
Preferred Qualifications
Experience with blockchain technologies
Knowledge of sports-related APIs or platforms
Familiarity with cryptocurrency trading systems
Experience with automated trading systems
Understanding of tokenization concepts
Certification in cloud computing or DevOps
What We Offer
Competitive salary
Comprehensive health insurance package
Flexible hybrid remote work arrangement
Generous PTO policy (20 days annual leave + 10 paid holidays)
Professional development opportunities
Stock options in a growing startup
Access to cutting-edge technologies and tools
Collaborative and dynamic work environment
Opportunities for career growth and advancement
Payment in Crypto