Principal Security Engineer, Security
Status
Boston, USA
Full time
Remote
Compensation is not specified
Role
Security Engineer
Description
Circle, a cutting-edge financial technology firm, sits at the forefront of the advancing internet of money. Simplifying global value transfer akin to digital data, Circle propels possibilities for seamless payments, commerce, and markets that drive economic prosperity and inclusion worldwide. With its pioneering infrastructure like USDC, a blockchain-based dollar, Circle empowers businesses, institutions, and developers to leverage these breakthroughs amid the evolving intersection of money and technology.
About Your Future Role
Circle upholds transparency and stability as core virtues as it expands its presence in leading global markets. Upholding company values of Multistakeholder approach, mindfulness, excellence-driven culture, and high integrity, the team seeks new members thriving in the remote teamwork environment fuelled by collaboration and diverse perspectives.Presenting a flexible and inclusive work atmosphere, where diverse insights are celebrated and collective ownership is promoted.
Your Responsibilities
Joining the Security Engineering team at Circle, the Principal Security Engineer will spearhead the execution of technical strategies, innovative tools, research, and processes relating to Product and Blockchain Security. Collaborating closely with Engineering, Infrastructure, and IT teams, your role extends to supporting cloud operations, software development, and endpoint security.
Key Responsibilities
- Collaborate with product management and software engineering teams across the software development lifecycle to ensure secure application design and implementation.
- Conduct vulnerability assessments on web3 and web2 applications and their underlying systems using automated tools and manual methods; oversee the resolution of identified issues.
- Recommend code enhancements to mitigate vulnerabilities and ensure application security.
- Implement security automation within the CI/CD pipeline.
- Develop secure coding standards and educational materials to support engineers in crafting secure code.
- Research vulnerabilities specific to blockchain technologies and embed best practices into Circle's security protocols.
- Act as a point of escalation for security incidents to conduct thorough investigations.
- Manage third-party vendors for security-related activities such as penetration testing projects.
- Contribute to the continuous enhancement of the application security program.
- Support additional security team initiatives, including threat modeling, vulnerability scanning, and audits.
Your Core Values
- Multistakeholder: Uphold respect and commitment to customers, shareholders, and the community.
- Mindful: Prioritize active listening, respect, and meticulous attention to detail.
- Driven by Excellence: Relentlessly pursue customer success, excellence, and goal achievement.
- High Integrity: Practice transparency and ethical standards in communication, rejecting dishonesty and manipulation.
Skills & Qualifications You Bring to Circle
- 7+ years of experience in cybersecurity roles, with 4+ years as a lead security engineer driving cybersecurity projects.
- Proficiency in securing software applications, conducting penetration testing, and implementing security features.
- Automation experience in security testing within CI/CD pipelines.
- Familiarity with AWS, GCP, and blockchain technologies like Ethereum, Bitcoin, Solana.
- Knowledge of public and private key cryptography and software defense techniques against common attacks.
- Proven ability to troubleshoot independently, collaborate across teams, and prioritize effectively.
- Financial services or financial technology background is advantageous.
- Bachelor's degree in relevant fields, certifications like CISSP or CEH are preferred.
- Expertise in programming languages like Solidity, Rust, Go, Move, JSON, Python.
- Remote work experience is a plus.
Additional Details
Day-one PERM sponsorship is available for qualified candidates. Annual compensation ranges vary based on factors like experience and organizational needs. The compensation package includes base pay, annual bonus, equity, and benefits like medical coverage, dental, vision, 401(k), discretionary vacation policy, sick leave, and paid holidays. Circle upholds equal opportunity employment principles and values diversity in its workforce.
(Base Pay Range: $200,000 - $257,500)
Skills Required
Circle
Website
www.circle.comCompany size
Not specified
Location
United States
Description
Not specified
Status
George I
Game Studio Hiring: Full-Stack, Mobile & 3D Web Developers
Part time
Remote
About Us
We are an established game studio developing HeroWarrior, a Unity-based web battle game that has been in active development for three years. Our project is supported by GameWorld (Netherlands) and we're currently preparing for version 2.0 with an expanded development team.
Following strategic restructuring in 2022, we're now building a distributed team across Europe and seeking talented developers to join our long-term project.
Open Positions
We are actively recruiting for the following roles:
UI/UX Designer
Specialization in gaming interface design
Experience with Unity UI systems preferred
Full-Stack Developers
Backend and frontend development for web platform
Experience with game-related web services preferred
Mobile Developers
Native mobile app development
Cross-platform experience valued
Unity Developers
Gameplay mechanics implementation
3+ years Unity experience required
3D Web Developers
WebGL and Three.js expertise
Browser-based 3D rendering experience
hat We Offer
Project Commitment: We're seeking long-term partnerships, not short-term contractors. This is an opportunity to grow with an established project backed by industry partners.
Compensation Structure:
Flexible payment options: hourly rates, monthly retainers, or milestone-based compensation
Rates negotiable based on experience and role
Initial evaluation period followed by standard employment terms
Work Environment:
Remote-friendly distributed team
Collaborative development process
Opportunity to work on a commercially-backed game project
Application Requirements
Please submit the following:
Portfolio/Resume - Detailed work history and relevant projects
Rate Expectations - Your preferred compensation structure and rates
Code Samples - GitHub repository, portfolio links, or previous work examples
Availability - Expected start date and commitment level
Evaluation Process Acknowledgment - Confirmation of willingness to complete a brief technical assessment
Ideal Candidates
Demonstrated passion for game development
Strong technical skills in relevant technologies
Experience working on long-term projects
Collaborative mindset and professional communication
Interest in building innovative gaming experiences
Next Steps
We are moving quickly to fill these positions. Qualified candidates will be contacted within one week for initial discussions and technical evaluation.
To apply, please send your complete application materials to vlad@gameworldcompany.com
We are an established game studio developing HeroWarrior, a Unity-based web battle game that has been in active development for three years. Our project is supported by GameWorld (Netherlands) and we're currently preparing for version 2.0 with an expanded development team.
Following strategic restructuring in 2022, we're now building a distributed team across Europe and seeking talented developers to join our long-term project.
Open Positions
We are actively recruiting for the following roles:
UI/UX Designer
Specialization in gaming interface design
Experience with Unity UI systems preferred
Full-Stack Developers
Backend and frontend development for web platform
Experience with game-related web services preferred
Mobile Developers
Native mobile app development
Cross-platform experience valued
Unity Developers
Gameplay mechanics implementation
3+ years Unity experience required
3D Web Developers
WebGL and Three.js expertise
Browser-based 3D rendering experience
hat We Offer
Project Commitment: We're seeking long-term partnerships, not short-term contractors. This is an opportunity to grow with an established project backed by industry partners.
Compensation Structure:
Flexible payment options: hourly rates, monthly retainers, or milestone-based compensation
Rates negotiable based on experience and role
Initial evaluation period followed by standard employment terms
Work Environment:
Remote-friendly distributed team
Collaborative development process
Opportunity to work on a commercially-backed game project
Application Requirements
Please submit the following:
Portfolio/Resume - Detailed work history and relevant projects
Rate Expectations - Your preferred compensation structure and rates
Code Samples - GitHub repository, portfolio links, or previous work examples
Availability - Expected start date and commitment level
Evaluation Process Acknowledgment - Confirmation of willingness to complete a brief technical assessment
Ideal Candidates
Demonstrated passion for game development
Strong technical skills in relevant technologies
Experience working on long-term projects
Collaborative mindset and professional communication
Interest in building innovative gaming experiences
Next Steps
We are moving quickly to fill these positions. Qualified candidates will be contacted within one week for initial discussions and technical evaluation.
To apply, please send your complete application materials to vlad@gameworldcompany.com
Payment in Crypto
Target Mafia
Web3 Growth Hacker (Enforcer of Expansion)
Full time
Hybrid
Description
About Target Mafia
Target Mafia is a syndicate of elite media buyers, data scientists, and creative capos dominating gambling, crypto, nutra, and adult niches. We operate on pure performance: if our partners win, we win.
We are expanding our crypto empire and need a Web3 Growth Hacker, our Enforcer of Expansion, to scale projects, grow communities, and execute high-ROI campaigns across Web3 ecosystems.
Working at Target Mafia
This is a fast-paced, results-driven role where strategy meets execution. You’ll identify growth opportunities, implement viral campaigns, and optimize channels to maximize performance. Your work will directly impact revenue and user acquisition across multiple projects.
Role
As a Web3 Growth Hacker, you will drive user acquisition, scale communities, and execute growth strategies that expand Target Mafia’s influence in the crypto space. You’ll combine creative tactics, data analysis, and guerrilla marketing to deliver measurable results.
Responsibilities
Plan and execute growth campaigns across Telegram, Discord, Twitter, and other Web3 channels.
Build partnerships and collaborations with crypto communities and influencers.
Track, analyze, and optimize campaigns for maximum ROI.
Identify viral trends and implement them to boost engagement and user acquisition.
Work closely with media buyer dons and creative capos to align growth efforts with marketing strategies.
Skills Required
Growth Hacking & Performance Marketing
Social Media Strategy & Community Building
Crypto & Web3 Knowledge
Influencer & Partnership Management
Data Analysis & Campaign Optimization
Guerrilla Marketing & Viral Campaign Execution
Creativity & Fast Problem Solving
Reasons to Join Our Team
Lead high-impact campaigns in trending Web3 and crypto markets
Work with an elite, performance-driven mafia of media buyers
Performance-based compensation in stablecoins, with bonuses for growth wins
Hands-on experience scaling high-stakes projects
Flexible, dynamic, and rewarding environment for top-tier talent
About Target Mafia
Target Mafia is a syndicate of elite media buyers, data scientists, and creative capos dominating gambling, crypto, nutra, and adult niches. We operate on pure performance: if our partners win, we win.
We are expanding our crypto empire and need a Web3 Growth Hacker, our Enforcer of Expansion, to scale projects, grow communities, and execute high-ROI campaigns across Web3 ecosystems.
Working at Target Mafia
This is a fast-paced, results-driven role where strategy meets execution. You’ll identify growth opportunities, implement viral campaigns, and optimize channels to maximize performance. Your work will directly impact revenue and user acquisition across multiple projects.
Role
As a Web3 Growth Hacker, you will drive user acquisition, scale communities, and execute growth strategies that expand Target Mafia’s influence in the crypto space. You’ll combine creative tactics, data analysis, and guerrilla marketing to deliver measurable results.
Responsibilities
Plan and execute growth campaigns across Telegram, Discord, Twitter, and other Web3 channels.
Build partnerships and collaborations with crypto communities and influencers.
Track, analyze, and optimize campaigns for maximum ROI.
Identify viral trends and implement them to boost engagement and user acquisition.
Work closely with media buyer dons and creative capos to align growth efforts with marketing strategies.
Skills Required
Growth Hacking & Performance Marketing
Social Media Strategy & Community Building
Crypto & Web3 Knowledge
Influencer & Partnership Management
Data Analysis & Campaign Optimization
Guerrilla Marketing & Viral Campaign Execution
Creativity & Fast Problem Solving
Reasons to Join Our Team
Lead high-impact campaigns in trending Web3 and crypto markets
Work with an elite, performance-driven mafia of media buyers
Performance-based compensation in stablecoins, with bonuses for growth wins
Hands-on experience scaling high-stakes projects
Flexible, dynamic, and rewarding environment for top-tier talent
VaultChain
Assistant in Financial Technology and Trading Strategies (with Training)
Berlin, Germany
Berlin, Germany
Part time
Remote
Description
We are offering an opportunity to join our team and learn about cross-market trading strategies, focusing on identifying price differences of assets across multiple platforms. This role provides hands-on experience in financial technology, data analysis, and trading support.
As part of this position, you will:
Gain practical knowledge of market analysis and trading workflows
Learn how to recognize and evaluate opportunities across different platforms
Develop your skills in risk management and decision-making
Work with a mentor who will guide you step by step through the learning process
What we provide:
Comprehensive training program designed for beginners
Ongoing mentorship and professional support
Flexible schedule (approx. 1 hour a day required for study and practice)
Remote work setup with the possibility to grow into a larger role over time
This is a part-time, entry-level opportunity suitable for candidates with little or no prior experience. What matters most is your willingness to learn and apply new knowledge in practice.
Compensation: Competitive monthly pay structure with opportunities for progression as skills develop
We are offering an opportunity to join our team and learn about cross-market trading strategies, focusing on identifying price differences of assets across multiple platforms. This role provides hands-on experience in financial technology, data analysis, and trading support.
As part of this position, you will:
Gain practical knowledge of market analysis and trading workflows
Learn how to recognize and evaluate opportunities across different platforms
Develop your skills in risk management and decision-making
Work with a mentor who will guide you step by step through the learning process
What we provide:
Comprehensive training program designed for beginners
Ongoing mentorship and professional support
Flexible schedule (approx. 1 hour a day required for study and practice)
Remote work setup with the possibility to grow into a larger role over time
This is a part-time, entry-level opportunity suitable for candidates with little or no prior experience. What matters most is your willingness to learn and apply new knowledge in practice.
Compensation: Competitive monthly pay structure with opportunities for progression as skills develop
Сrypto.com
Head of Custody Security
Madrid, Spain
Madrid, Spain
Full time
Hybrid
Responsibilities
Conduct, design, and execute testing of security controls encompassing identity management, key management, and infrastructure (network and cloud) configurations.
Assist client assurance activities, including addressing Requests for Proposals (RFPs), Requests for Information (RFIs), and Due Diligence Questionnaires (DDQs).
Identify and analyze trends in client inquiries, offering feedback to internal teams to enhance documentation and control readiness.
Engage in security due diligence and continuous monitoring for Web3/blockchain vendors, evaluating control maturity, reviewing SOC reports and security documentation, and pinpointing residual risks.
Coordinate external audit activities, such as walk-throughs, evidence collection, and response tracking.
Recognize and evaluate gaps in existing and new processes, subsequently formulating and monitoring remediation recommendations to completion (e.g., onboarding flow).
Develop and sustain comprehension of applicable financial regulatory security requirements, ensuring control alignment.
Research and share information security best practices, emerging threats, and mitigation strategies with internal teams.
Evaluate and suggest next-generation security tools, automation, and technologies to enhance overall security posture.
Review blockchain network or protocol upgrades for potential security impacts on the platform.
Requirements
Minimum of 8 years of pertinent experience in security assurance, audit, compliance, or cloud security engineering.
Demonstrated proficiency in testing and validating security controls regarding IAM, key management, and network/cloud environments.
Solid understanding of Identity and Access Management (IAM) principles.
Knowledge of cryptographic key management, HSMs, and KMS systems.
Proficient in cloud and network security architecture and configuration.
Proven track record in supporting SOC 1, SOC 2, ISO 27001, PCI DSS, or equivalent external audits and assessments.
Exposed to major cloud platforms (AWS, GCP, Azure) and infrastructure-as-code.
Experience in preparing client assurance materials, RFP/RFI/DDQ responses, and evidence documentation.
Familiarity with blockchain platforms or digital asset custody systems considered a plus.
Capable of working autonomously and effectively under pressure.
Excellent verbal and written communication skills.
Pragmatic and solution-oriented approach, capable of balancing security requirements with operational feasibility and business needs.
Conduct, design, and execute testing of security controls encompassing identity management, key management, and infrastructure (network and cloud) configurations.
Assist client assurance activities, including addressing Requests for Proposals (RFPs), Requests for Information (RFIs), and Due Diligence Questionnaires (DDQs).
Identify and analyze trends in client inquiries, offering feedback to internal teams to enhance documentation and control readiness.
Engage in security due diligence and continuous monitoring for Web3/blockchain vendors, evaluating control maturity, reviewing SOC reports and security documentation, and pinpointing residual risks.
Coordinate external audit activities, such as walk-throughs, evidence collection, and response tracking.
Recognize and evaluate gaps in existing and new processes, subsequently formulating and monitoring remediation recommendations to completion (e.g., onboarding flow).
Develop and sustain comprehension of applicable financial regulatory security requirements, ensuring control alignment.
Research and share information security best practices, emerging threats, and mitigation strategies with internal teams.
Evaluate and suggest next-generation security tools, automation, and technologies to enhance overall security posture.
Review blockchain network or protocol upgrades for potential security impacts on the platform.
Requirements
Minimum of 8 years of pertinent experience in security assurance, audit, compliance, or cloud security engineering.
Demonstrated proficiency in testing and validating security controls regarding IAM, key management, and network/cloud environments.
Solid understanding of Identity and Access Management (IAM) principles.
Knowledge of cryptographic key management, HSMs, and KMS systems.
Proficient in cloud and network security architecture and configuration.
Proven track record in supporting SOC 1, SOC 2, ISO 27001, PCI DSS, or equivalent external audits and assessments.
Exposed to major cloud platforms (AWS, GCP, Azure) and infrastructure-as-code.
Experience in preparing client assurance materials, RFP/RFI/DDQ responses, and evidence documentation.
Familiarity with blockchain platforms or digital asset custody systems considered a plus.
Capable of working autonomously and effectively under pressure.
Excellent verbal and written communication skills.
Pragmatic and solution-oriented approach, capable of balancing security requirements with operational feasibility and business needs.
Сrypto.com
Head of Custody Security
Dublin, Ireland
Dublin, Ireland
Full time
Hybrid
Responsibilities
Conduct, create, and execute testing of security controls across identity management, key management, and infrastructure (network and cloud) setups.
Assist with client assurance tasks, including addressing Requests for Proposals (RFPs), Requests for Information (RFIs), and Due Diligence Questionnaires (DDQs).
Recognize and assess trends in client inquiries and offer feedback to internal teams for enhancing documentation and control readiness.
Perform security due diligence and continuous monitoring for Web3/blockchain vendors, by evaluating their control maturity, reviewing SOC reports and security documents, and identifying any remaining risks.
Coordinate external audit activities, such as walkthroughs, gathering evidence, and tracking responses.
Pinpoint and study gaps in current and new processes, and then create and monitor remediation suggestions to completion (e.g., onboarding processes).
Develop and sustain knowledge of pertinent financial regulatory security requirements and guarantee control alignment.
Investigate and distribute details on information security best practices, emerging risks, and mitigation approaches with internal teams.
Evaluate and suggest next-generation security tools, automation, and technologies to enhance overall security stance.
Review potential security impacts on the platform resulting from blockchain network or protocol upgrades.
Requirements
Minimum of 8 years of suitable experience in security assurance, audit, compliance, or cloud security engineering.
Demonstrated proficiency in testing and affirming security controls within IAM, key management, and network/cloud environments.
Deep comprehension of Identity and Access Management (IAM) principles.
Familiarity with cryptographic key management, HSMs, and KMS systems.
Strong understanding of cloud and network security architecture and configuration.
Proven track record supporting SOC 1, SOC 2, ISO 27001, PCI DSS, or similar external audits and evaluations.
Exposure to leading cloud platforms (AWS, GCP, Azure) and infrastructure-as-code practices.
Experience in preparing client assurance materials, RFP/RFI/DDQ responses, and evidence documentation.
Knowledge of blockchain platforms or digital asset custody systems is advantageous.
Ability to work autonomously and handle demanding situations effectively.
Outstanding verbal and written communication skills.
Pragmatic and solution-driven mindset, capable of harmonizing security requirements with operational viability and business demands.
Conduct, create, and execute testing of security controls across identity management, key management, and infrastructure (network and cloud) setups.
Assist with client assurance tasks, including addressing Requests for Proposals (RFPs), Requests for Information (RFIs), and Due Diligence Questionnaires (DDQs).
Recognize and assess trends in client inquiries and offer feedback to internal teams for enhancing documentation and control readiness.
Perform security due diligence and continuous monitoring for Web3/blockchain vendors, by evaluating their control maturity, reviewing SOC reports and security documents, and identifying any remaining risks.
Coordinate external audit activities, such as walkthroughs, gathering evidence, and tracking responses.
Pinpoint and study gaps in current and new processes, and then create and monitor remediation suggestions to completion (e.g., onboarding processes).
Develop and sustain knowledge of pertinent financial regulatory security requirements and guarantee control alignment.
Investigate and distribute details on information security best practices, emerging risks, and mitigation approaches with internal teams.
Evaluate and suggest next-generation security tools, automation, and technologies to enhance overall security stance.
Review potential security impacts on the platform resulting from blockchain network or protocol upgrades.
Requirements
Minimum of 8 years of suitable experience in security assurance, audit, compliance, or cloud security engineering.
Demonstrated proficiency in testing and affirming security controls within IAM, key management, and network/cloud environments.
Deep comprehension of Identity and Access Management (IAM) principles.
Familiarity with cryptographic key management, HSMs, and KMS systems.
Strong understanding of cloud and network security architecture and configuration.
Proven track record supporting SOC 1, SOC 2, ISO 27001, PCI DSS, or similar external audits and evaluations.
Exposure to leading cloud platforms (AWS, GCP, Azure) and infrastructure-as-code practices.
Experience in preparing client assurance materials, RFP/RFI/DDQ responses, and evidence documentation.
Knowledge of blockchain platforms or digital asset custody systems is advantageous.
Ability to work autonomously and handle demanding situations effectively.
Outstanding verbal and written communication skills.
Pragmatic and solution-driven mindset, capable of harmonizing security requirements with operational viability and business demands.