Decentralized finance (DeFi) continues to evolve, providing new opportunities for automated financial services. However, with innovation comes risk, and security vulnerabilities in smart contracts can lead to financial losses and reputational damage. At softstack, we specialize in comprehensive blockchain security audits, ensuring that protocols maintain the highest levels of security, efficiency, and compliance.
Service
multiple smart contract audits
One of our recent engagements involved working with fija, a crypto earn product offering automated and tokenized investment strategies. Since June 2023, we have conducted four independent security audits for fija, focusing on its core protocol, vault mechanisms, and key DeFi integrations.
This article outlines our audit methodology, key findings, and how we helped fija strengthen its smart contract security.
fija is a Munich, Liechtenstein and Czech Republic-based fintech company specializing in automated and tokenized DeFi yield strategies. fija is transforming how people earn interest on their crypto assets with a compliant, transparent, and easy-to-use “Crypto Earn” product. By offering MiCAR and MiFID compliant crypto yield products, fija enables users to earn yield while maintaining compliance with financial regulations. In doing so, fija bridges the gap between traditional and decentralized finance, making DeFi more accessible, sustainable, and integrated into the broader financial ecosystem.
At its core, fija enables automated investment strategies by integrating with leading DeFi protocols, including:
fija’s architecture is highly complex, efficiently allocating assets across multiple DeFi protocols to optimize returns while managing risk. The protocol employs a smart contract whitelisting system to ensure security and prevent unauthorized access to user funds.
Given the technical complexity and the financial stakes involved, fija required a rigorous audit process to verify the security of its vaults, investment strategies, and transaction mechanisms.
The four audits conducted by softstack covered the following components of the fija protocol:
To assess the security of these components, we applied a multi-layered approach, including:
Throughout the audits, we identified over 50 vulnerabilities across various components. While no critical security risks were found, several medium and low-severity issues were reported and addressed.
All identified vulnerabilities were resolved and also integrated into unit tests to prevent future issues.
Learn more about the audit findings → Read the full report on GitHub
A smart contract audit isn’t just about finding vulnerabilities—it’s about ensuring long-term security and resilience. fija actively collaborated with our audit team, promptly addressing each finding and implementing all recommended improvements.
Key enhancements from our partnership include:
fija’s proactive approach to security ensures that users can interact with fija’s earn products confidently, knowing their assets are protected.
With the continued expansion of decentralized finance, security remains a critical concern for enterprise clients, institutional investors, and DeFi developers. A single smart contract vulnerability can lead to millions in losses, making regular security assessments essential.
For DeFi protocols, smart contract audits provide:
At softstack, we help businesses, financial institutions, and DeFi platforms strengthen their security posture through deep technical expertise and real-world attack simulations.
fija’s commitment to security sets a benchmark for responsible DeFi development. By undergoing extensive audits and implementing industry best practices, they have reinforced trust in their earn product and ensured the integrity of their investment strategies.
As DeFi continues to evolve, strong security frameworks and proactive risk mitigation will be essential for long-term success. Whether you are a startup or an established protocol, ensuring the security of your smart contracts is critical for maintaining investor confidence and regulatory compliance.
Want to strengthen your DeFi security? softstack offers top-tier smart contract audits and risk assessments to help you stay protected.
To learn more about our security services or schedule an audit, contact us at hello@softstack.io.
