About Legacy Legacy is an easy-to-use, non-custodial Web3 wallet designed to protect digital assets through beneficiary protection and seamless De Fi access.
Users can swap across chains, earn yield in one click, and safeguard wealth for the next generation.
About the Software Division We are building a portfolio of software products inside the Decentralized Masters ecosystem, including: Legacy Wallet
- a non-custodial Web3 wallet with beneficiary protection and seamless De Fi access Trading Bot
- automated crypto execution tools for serious investors Future fintech and investor infrastructure tools We are now building the retention and lifecycle engine that will power long?

About The Role
You will be the single person responsible for the security of a platform that tracks hundreds of millions in digital assets.
Someone who reads a pull request and catches the injection vulnerability that two senior developers missed.
Your primary responsibilities are security and quality assurance.
You own penetration testing, vulnerability assessments, threat modeling, automated test frameworks, and CI quality gates across every product we ship.
AWS, CI/CD pipelines, monitoring, and incident response.
And because we are a small, senior team, you will write production code when security and QA responsibilities are covered.
driven fintech and crypto companies where a single security failure can destroy user trust overnight.
Security (Primary) Own the security posture across all products: If something gets breached, it is your problem.
If nothing gets breached, it is because of your work Conduct regular penetration testing, vulnerability assessments, and threat modeling aligned with OWASP standards and methodologies Ensure full coverage of the OWASP Top 10 in application security testing,



code reviews, and deployment checks Perform security?focused code reviews across frontend, backend, and infrastructure code, catching what standard code reviews miss Implement and manage secrets management (Vault, AWS Secrets Manager, or KMS), access controls, and least?specific attack vectors: phishing campaigns, wallet exploits, API key compromises, supply chain attacks, and social engineering Manage and coordinate external security audits and penetration tests from third?party firms Quality Assurance & Testing (Primary) Design and implement test strategies across all products: unit tests, integration tests, end?to?end tests, API tests, and regression suites Build and maintain automated testing frameworks and CI quality gates that prevent broken code from reaching production Define and track quality metrics: test coverage, flakiness rate, regression detection latency, and bug escape rate Write and execute security test cases: authentication flows, authorization controls, input validation, API abuse scenarios, and edge cases around financial data Perform both white?box testing, leveraging full codebase access to catch issues that surface?level QA would miss Test across the full stack: frontend UI, backend APIs, database queries, third?chain interactions Infrastructure & Dev Ops (Foundation) Maintain and improve cloud infrastructure on AWS using Infrastructure as Code (Terraform or Cloud Formation)



Own CI/CD pipelines (Git Hub Actions preferred): automated testing, security scanning, linting, and deployment Harden infrastructure: network security, IAM policies, container security, and environment isolation Build logging, monitoring, and alerting across all services (Cloud Watch, Prometheus, Grafana, or equivalent) Ensure audit trails for user actions, system changes, and access events Manage production reliability, incident response, and cost optimization Fullstack Development (When the fortress is secure) Contribute production code across frontend and backend, bringing a security?first mindset to every feature you build Build features, fix bugs, and ship improvements alongside the engineering team Every line you write should make the product better and harder to break: input validation, error handling, authentication, and data protection by default Participate in architecture discussions and code reviews, advocating for testability, reliability, and security in every decision Requirements Required 5+ years in software engineering roles with meaningful, hands?on security and QA experience.
If your security experience is theoretical, this is not the right fit Fullstack development

experience:
you can build and ship features across frontend (React or equivalent) and backend (Node.
Js, Python, Go, or equivalent) Hands?on penetration testing and vulnerability assessment experience across web applications, APIs, and cloud infrastructure Strong working knowledge of OWASP standards, including the OWASP Top 10, OWASP Testing Guide, and OWASP secure coding practices Experience building automated test frameworks and integrating testing into CI/CD pipelines AWS expertise (EC2, ECS/EKS, Lambda, VPC,

📌 Security DevOps Engineer (Barcelona)
🏢 Decentralized Masters
📍 Barcelona