Senior Application Security Engineer

RootstockLabs; København; Remote; DKK 900,000 - 1,300,000; Full time

Benefits offered by this job

100% Remote Work

Paid vacation and sick leave

Training sponsorship

Global coworking access

Job summary

RootstockLabs is seeking an Application Security Engineer to secure our Bitcoin-secured DeFi infrastructure. You will review code, smart contracts, and protocol changes, and build security automation across the development lifecycle.

You will model threats with dev teams and coordinate bug bounties and audits with external parties. You will research attack techniques in EVM/bridges/p2p and translate findings into defenses, while supporting incident investigations and CI security gates.

Qualifications

• 3+ years of experience in Application Security or Security Engineering.
• Solid grasp of common vulnerability classes (OWASP Top 10) and secure code review in Java plus at least one of TypeScript/JavaScript, Python, Go, or Rust.
• Hands-on experience with blockchain security: smart contract auditing (Solidity/EVM) or protocol/node-level security.
• Experience building and operating security automation, AI-assisted workflows (LLM-based triage, code review, or scanning), SAST/DAST, dependency and secret scanning, and CI/CD security gates.
• Fluent English

Responsibilities

• Perform security reviews of source code, smart contracts, and protocol changes across RootstockLabs projects.
• Participate in design and architecture reviews; threat-model new products and features with development teams.
• Triage and validate bug bounty reports; assess severity and coordinate remediation with engineering.
• Collaborate on external security audits: scope engagements and work with third-party auditors through to the resolution of findings.
• Build and operate security automation, including AI-assisted code review, scanning, and findings-triage pipelines.
• Research attack techniques relevant to the ecosystem (EVM, bridges, p2p) and turn findings into concrete defenses: monitoring alerts, CI security checks, and hardening changes.
• Support incident investigations when application-layer issues arise

Skills

Security engineering

OWASP Top 10

Secure code review

Threat modeling

CI/CD security gates

English fluency

Tools

Solidity/EVM auditing

SAST/DAST

CI/CD tooling

Job description

About The Role

As anApplication Security Engineerat RootstockLabs, you will help secure our Bitcoin-secured DeFi infrastructure by reviewing code, smart contracts, and protocol changes, and by building the security automation that keeps our development lifecycle safe. You will work closely with development teams on threat modeling and architecture reviews, manage our bug bounty program end to end, and coordinate external security audits with third-party auditors. You will also research attack techniques relevant to our ecosystem (EVM, bridges, p2p) and translate them into concrete defenses, and support incident investigations when application-layer issues arise.

Key Responsibilities

• Perform security reviews of source code, smart contracts, and protocol changes across RootstockLabs projects
• Participate in design and architecture reviews; threat-model new products and features with development teams
• Triage and validate bug bounty reports; assess severity and coordinate remediation with engineering
• Collaborate on external security audits: scope engagements and work with third-party auditors through to the resolution of findings
• Build and operate security automation, including AI-assisted code review, scanning, and findings-triage pipelines
• Research attack techniques relevant to the ecosystem (EVM, bridges, p2p) and turn findings into concrete defenses: monitoring alerts, CI security checks, and hardening changes
• Support incident investigations when application-layer issues arise

What You Bring

• 3+ years of experience in Application Security or Security Engineering
• Solid grasp of common vulnerability classes (OWASP Top 10) and secure code review in Java plus at least one of TypeScript/JavaScript, Python, Go, or Rust
• Hands-on experience with blockchain security: smart contract auditing (Solidity/EVM) or protocol/node-level security
• Experience building and operating security automation, AI-assisted workflows (LLM-based triage, code review, or scanning), SAST/DAST, dependency and secret scanning, and CI/CD security gates
• Fluent English

NICE TO HAVE

• Experience in bug bounty triage or vulnerability disclosure programs
• Experience mitigating network-level attacks (p2p, eclipse, DoS) or analyzing consensus-level attack scenarios
• Offensive security background (pentesting, red team, CTFs, exploit development)
• Public security research: CVEs, bug bounty track record, audit reports, conference talks
• Knowledge of C/C++ (for node/client codebases)
• Experience with fuzzing (smart contracts or native code)

Rooties Benefits

At RootstockLabs, we don't just offer a job, we offer a community. Here's what you can expect when you join us:

• Competitive compensation package and unique benefits designed to support your growth and well-being.
• 100% Remote Work working within a Central European to Argentinian time-zone window (UTC-3 to UTC+2, with about an hour's flexibility either side), and with access to global coworking spaces.
• Work-Life Balance: Paid vacation and sick leave days
• Continuous Learning: Access to training programs, language courses, and learning sponsorship annually.
• Unique Projects: Work with cutting-edge blockchain technology in a global, diverse team.

About Rootstocklabs

RootstockLabs is a key contributor to Rootstock, Bitcoin's Financial Infrastructure for lending, yield, and onchain capital markets. We build and commercialize the institutional infrastructure that turns Bitcoin into productive capital.

• What we do: Develop and commercialize Bitcoin-backed lending, tokenized real-world assets, and onchain financial strategies
• Who we work with: Leading custodians, asset managers, and financial institutions
• Why it matters: Rootstock is secured by 80%+ of Bitcoin's hash power and has run with 100% uptime since 2018 (bringing Ethereum-style programmability to the world's hardest money).
• Proof it works: 200+ dApps live on Rootstock, from BTCFi protocols like Sushiswap and Oku to institutional names like Mercado Bitcoin, Animoca Brands, and Paystand