Ninety Eight is looking for a Senior DeFi Smart Contract Developer to join our core blockchain engineering team.
You’ll play a critical part in building secure and scalable DeFi products such as DEX Aggregators, liquidity protocols, and yield strategies.
In this role, you will design, implement, and optimize DeFi smart contracts on EVM- compatible blockchains (e.g. Ethereum, Arbitrum, Base, BSC).
JOB RESPONSIBILITIES
Stay up- to- date with emerging trends in blockchain and DeFi (e.g., MEV, L2 scaling, account abstraction, zk- rollups).
Design and develop secure, gas- efficient smart contracts on EVM- compatible blockchains for DeFi applications (e.g. DEX Aggregators, Liquidity Pools, Yield Farming).
Conduct thorough testing and auditing, addressing vulnerabilities and collaborating with external auditors and security partners.
Architect and document smart contract systems, ensuring scalability, modularity, and security.
Collaborate cross- functionally with product managers, frontend/backend engineers, and DevOps to deliver high- quality software.
Integrate external DeFi protocols, research new technologies, and write detailed technical documentation.
Mentor junior developers and contribute to establishing smart contract best practices and internal standards.
JOB REQUIREMENTS
Must Have
Strong proficiency in Solidity, with solid understanding of gas optimization, reusable libraries, and best practices.
Good command of written and spoken English, especially for reading technical documentation.
Knowledge of common smart contract vulnerabilities and mitigation techniques (e.g. reentrancy, overflow, flash loan, MEV).
Experience with development frameworks and tools such as Hardhat, Foundry, OpenZeppelin, Slither, MythX.
Deep understanding of DeFi protocols (AMMs, DEXs, lending, staking, liquidity mining), familiarity with protocol math is a strong plus.
Strong background in software architecture, design patterns, and clean code principles.
Excellent problem- solving skills, strong ownership mindset, and ability to perform under high- pressure deadlines.
3+ years of proven experience developing and deploying secure, production- ready smart contracts on EVM- compatible blockchains.
Nice to Have
Experience building or integrating with Layer 2 solutions (Optimism, Arbitrum, Base, zkSync, etc.).
Familiarity with MEV protection strategies and advanced on- chain analytics.
Experience mentoring or leading small technical teams.
Experience with smart contract auditing or formal verification.
WHAT WE ARE OFFERING
At Ninety- Eight, we believe in providing a comprehensive and rewarding benefits package to our valued employees. We prioritize the well- being and satisfaction of our team members and strive to create a positive and fulfilling work environment. Here are the benefits we offer:
Full- paid compulsory insurance according to Vietnam Labor Law
13th- month salary & performance bonus
Semiannual performance- salary review.
Premium Healthcare Insurance
100% official salary during the probation period.
12 days annual leave & other leaves, as below:
Unlimited potential for career growth; budget for training and self- development
Working hours: 8 hours x 5 days/week (Monday to Friday)
Fantastic working environment with friendly and talented colleagues
Charity Leave: Contribute to charitable organizations with 2 days of paid leave per year for volunteer work.
Birthday Leave: Enjoy 1 day of paid leave to celebrate your birthday with loved ones.
Provision of Macs/Laptops and other necessary work equipment
Yearly company trips and team- bonding activities
Well- being Leave: you have 2 days of paid leave to prioritize your physical, mental, and emotional health
Allowances for transportation, lunch, coffee, and team- bonding
ABOUT US
We&039;re committed to building a diverse and inclusive workplace, where employees are encouraged to grow and learn new skills. The company values creativity, collaboration, and a strong work ethic, and is always looking for talented individuals who are passionate about blockchain technology and want to be a part of a fast- growing industry.
If your CV is suitable for the position, we will send an email to notify you of the next round within 7 days. Due to the number of received applications, only shortlisted candidates shall be contacted. Thank you for your understanding.
Ninety- Eight is a software company focused in blockchain- technology based in Vietnam. We provide a wide range of services related to the blockchain industry, including trading platforms, wallet services, and decentralized finance (DeFi) products. Our mission is to promote the adoption of blockchain technology and make it more accessible to people around the world.
