Full-Stack Web & Application Development
Modern React-based front-ends and production-grade backend systems designed for growth, speed, and maintainability.
Secure Systems. Enterprise Reliability. Premium Execution.
I architect and deliver secure systems at enterprise scale.
Leandros Holleman, founder of LnL Labs. Builder of Keypact, CTO of GenWealth, and operator of one of Cardano's most reliable stake pools. Now delivering secure, scalable software solutions for US clients through B2B contracts via Cyprus LLC.
Open to 1-2 high-impact US B2B contracts via my Cyprus LLC • Starting Q3/Q4 2026 • Strictly max 40 hours/week
About
Meet Leandros Holleman
I'm the full-stack engineer behind Keypact (post-quantum secure key infrastructure), CTO and lead developer of GenWealth (the leading inheritance and recovery platform bridging digital assets with real-world compliance), and SPO of The Brothership Pool (BSP) - a high-uptime, large-stake Cardano infrastructure operation with 957+ delegators and 28M+ ADA secured.
With 4+ years shipping production-grade systems on complex architectures, I specialize in turning ambitious ideas into robust, secure, user-friendly applications. My experience spans secure multi-signature systems, recovery protocols, high-availability infrastructure, React front-ends, DevOps/CI-CD pipelines, and cloud optimization.
After delivering GenWealth, I'm selectively taking on US-based clients who want premium development talent without the crypto volatility - delivering the stability and income needed to build lasting value (including my own dream house).
All client engagements are handled through RILUTA LIMITED (Cyprus) for clean billing and maximum simplicity.
Services
What I Deliver
Secure Systems Architecture & Key Management
Defense-in-depth architecture for sensitive workflows, secure key handling, and resilient operational controls.
Fintech & Wealth-Tech Solutions
Inheritance, recovery, and compliant asset workflow platforms with user trust, reliability, and regulatory awareness in mind.
DevOps & Cloud Infrastructure
CI/CD pipelines, scalable cloud hosting, observability, and validator-grade reliability for mission-critical systems.
Custom Smart Contract / Backend Logic
Specialized automation and backend business logic, implemented only where it creates clear operational and financial value.
End-to-End Project Consulting & Management
From architecture decisions to launch execution, with clear communication, realistic planning, and accountable delivery.
B2B Engagement
Engaging via RILUTA LIMITED (Cyprus)
All projects are delivered professionally through my Cyprus LLC for straightforward B2B engagement.
- • Simple USD invoicing (Wise, ACH, Stripe)
- • W-8BEN-E form provided
- • Clear Statements of Work with max 40 hours/week
- • Net-15/30 payment terms
- • NDA-friendly
Portfolio
Selected Work
Case Study 01
Keypact
Post-quantum cryptography infrastructure and secure key management systems engineered for high-assurance operational environments.
- Hardened key workflows for high-assurance reliability
- Lower operational risk through resilient architecture patterns
- Built for long-term scalability and audit-ready trust
Case Study 02
GenWealth (in final development)
Full-stack inheritance and recovery platform with real-world asset integration and legal compliance frameworks.
- Reliable multi-layer user and asset recovery flows
- Compliance-aware architecture for sensitive financial workflows
- Production-focused delivery balancing UX and operational safety
Case Study 03
BSP (The Brothership Pool)
Mission-critical infrastructure operation managing 28M+ ADA with 99.9%+ uptime and dependable operational performance.
- 99.9%+ uptime operations for mission-critical infrastructure
- Stable performance under sustained network and load demands
- Proven trust and reliability across a large active delegator base
Trust Signals
Trusted by high-stakes infrastructure projects and next-gen fintech platforms.
"Thanks for stepping in to clean up critical code before release. Strong support under pressure."
"Leandros helped us stabilize a complex fintech workflow and delivered with exceptional clarity."
"Premium execution, no drama, and architecture decisions we could trust from day one."
Contact
Ready for stable, high-impact collaboration?
If you are building in fintech, wealth tech, secure SaaS, or enterprise software and need dependable execution, let's discuss your roadmap.
US time zones preferred • Remote • High-impact B2B contracts via Cyprus LLC