Software Engineer (Engineer III to Principal) - Formal Methods
New York, USA +2
Full time
Remote
Compensation is not specified
Role
Software Engineer
Description
** Why Us?**
In a world witnessing tremendous innovation fueled by blockchain technology, ensuring the security and correctness of blockchain code, including protocols and smart contracts, is paramount. CertiK, a leading blockchain security company, is dedicated to securing the digital space by leveraging cutting-edge academic techniques to safeguard blockchain code. Join us in our mission to develop automated analyses for provably secure and correct blockchain applications.
What You Will Do
As a Research Software Engineer at CertiK, you will be responsible for designing and implementing tools that autonomously verify the accuracy of smart contracts and detect security vulnerabilities and bugs in them. Various positions are available at different seniority levels, with titles and responsibilities aligned with experience and background.
Working alongside a diverse team of programming language experts, you will contribute to the creation of tools based on techniques like symbolic model checking, SAT/SMT solving, abstract interpretation, data flow analysis, and deductive verification. You will engage in all aspects of tool development, from conception to enhancements, in a collaborative and supportive environment that encourages continuous learning and professional growth.
About You
You possess a background in programming language theory and automated reasoning and thrive on applying theoretical computer science outcomes to practical solutions. You excel in solving complex computational challenges and have a history of delivering impactful results that enhance user workflows. Collaboration is key to you, as you enjoy exchanging ideas, engaging in group brainstorming, and providing and receiving constructive feedback. You are adaptable and understand the dynamic nature of a startup environment, where versatility is essential.
Responsibilities
- Enhance automated program verification tools and foster the development of new tools
- Refine algorithms for symbolic software model checking, such as BMC, CEGAR, and IC3/PDR
- Develop translators for diverse input languages into optimized models for automated analysis
- Define new security properties for smart contracts and integrate them into verification tools
- Collaborate closely with software engineers to drive tool development and problem-solving efforts
- Engage in the complete software lifecycle, including analysis, design, testing, operations, and customer support
Required Qualifications
- Master's Degree in Computer Science or equivalent experience
- Minimum of 4 years of software development experience
- At least 2 years of experience in model checking, formal verification, SAT/SMT solving, or related fields
- Proficiency in fundamental computer science concepts
Preferred Qualifications
- Ph.D. in automated reasoning or related discipline
- Record of publications in conferences like POPL, CAV, and TACAS
- Familiarity with functional programming languages like OCaml or Haskell
- Strong problem-solving skills and a willingness to learn and collaborate
- Previous experience in a professional software development setting
About the Company
Established in 2018 by Yale University and Columbia University professors, CertiK is a pioneer in blockchain security, utilizing advanced technology to safeguard blockchain protocols and smart contracts. With a commitment to enhancing security across the digital realm, CertiK integrates cutting-edge academic innovations into enterprise solutions, enabling the development of secure and accurate mission-critical applications.
Compensation
The targeted annual base salary for this role in the U.S. ranges from $115,000 to $230,000. The actual salary offered will depend on the candidate's skills and background.
At CertiK, full-time employees receive comprehensive benefits, including medical, vision, and dental insurance, a 401(k) plan with company matching, life insurance, and flexible paid time off. The company also offers a variable commission program for certain roles.
CertiK adheres to federal employment regulations and maintains a commitment to equal opportunity employment, welcoming applicants without bias based on various characteristics.
All CertiK team members are encouraged to actively promote diversity within their teams and the organization as a whole.
Skills Required
CertiK
Website
www.certik.comCompany size
Not specified
Location
United States
Description
Not specified
DeGameVerse
UI/UX Designer
Part time
Remote
About DeGameVerse
DeGameVerse is building a next-generation Web3 gaming ecosystem where developers create games and players explore, play, and earn through a unified platform experience.
We are focused on:
Walletless onboarding
Mobile-first gaming experience
AI-assisted game creation
Clean and accessible Web3 UX
This is an early-stage startup currently building its core founding team.
Role Overview
We are looking for a creative UI/UX Designer who can help shape the visual identity and user experience of DeGameVerse.
You will work closely with the founder and development team to design a smooth, modern, and engaging platform experience for both players and developers.
This is a startup builder role with high creative ownership.
Responsibilities
Design user-friendly interfaces for web and mobile
Create UI flows for player dashboard, developer dashboard, and game hub
Build consistent design systems and reusable components
Improve user onboarding and overall UX experience
Design wireframes, mockups, and interactive prototypes
Collaborate closely with developers during implementation
Ensure responsive and modern UI standards
Requirements
Experience with Figma or similar design tools
Strong understanding of UI/UX principles
Ability to create clean, modern, and intuitive interfaces
Good communication and collaboration skills
Startup mindset and problem-solving ability
Bonus Skills
Experience designing gaming or Web3 products
Motion UI / animation knowledge
Basic frontend understanding (HTML/CSS/React concepts)
Experience with mobile-first design systems
What We Offer
Early core team opportunity
Equity-based contribution model
High creative freedom and ownership
Opportunity to help shape a new Web3 gaming ecosystem
Portfolio-level product design experience
⚠️ Important Note
This is an early-stage startup role.
No fixed salary initially. Compensation is equity-based until funding or revenue is secured.
DeGameVerse is building a next-generation Web3 gaming ecosystem where developers create games and players explore, play, and earn through a unified platform experience.
We are focused on:
Walletless onboarding
Mobile-first gaming experience
AI-assisted game creation
Clean and accessible Web3 UX
This is an early-stage startup currently building its core founding team.
Role Overview
We are looking for a creative UI/UX Designer who can help shape the visual identity and user experience of DeGameVerse.
You will work closely with the founder and development team to design a smooth, modern, and engaging platform experience for both players and developers.
This is a startup builder role with high creative ownership.
Responsibilities
Design user-friendly interfaces for web and mobile
Create UI flows for player dashboard, developer dashboard, and game hub
Build consistent design systems and reusable components
Improve user onboarding and overall UX experience
Design wireframes, mockups, and interactive prototypes
Collaborate closely with developers during implementation
Ensure responsive and modern UI standards
Requirements
Experience with Figma or similar design tools
Strong understanding of UI/UX principles
Ability to create clean, modern, and intuitive interfaces
Good communication and collaboration skills
Startup mindset and problem-solving ability
Bonus Skills
Experience designing gaming or Web3 products
Motion UI / animation knowledge
Basic frontend understanding (HTML/CSS/React concepts)
Experience with mobile-first design systems
What We Offer
Early core team opportunity
Equity-based contribution model
High creative freedom and ownership
Opportunity to help shape a new Web3 gaming ecosystem
Portfolio-level product design experience
⚠️ Important Note
This is an early-stage startup role.
No fixed salary initially. Compensation is equity-based until funding or revenue is secured.
DeGameVerse
Game Developer / AI Integration Developer — Startup
Full time
Remote
About DeGameVerse
DeGameVerse is building a next-generation Web3 gaming ecosystem where developers create games and players play, progress, and earn within a unified platform.
We are building:
▫️ AI-assisted game creation tools
▫️ Web-based casual & idle games
▫️ Player-first reward economy
▫️ Walletless onboarding experience
This is an early-stage startup forming its core founding team.
Role Overview
We are looking for a creative and technically strong Game Developer who can also explore AI-driven game generation and integration.
You will help build engaging web-based games and connect them to the DeGameVerse ecosystem.
This is a builder role, not a traditional employment position.
Responsibilities
Develop simple to mid-level web games (JavaScript / Phaser / Unity WebGL)
Design core gameplay mechanics (progression, rewards, loops)
Integrate games into DeGameVerse platform ecosystem
Work on AI-assisted game creation concepts and prototypes
Handle game logic, scoring, and interaction systems
Collaborate with full-stack developer for platform integration
Optimize games for mobile-first web experience
Requirements
Strong understanding of JavaScript or game development frameworks
Experience building browser-based or mobile-friendly games
Good grasp of game mechanics and player engagement loops
Creative mindset for designing fun and scalable gameplay
Bonus Skills
Experience with Phaser / Unity WebGL / Three.js
Exposure to AI tools (GPT APIs, procedural generation, etc.)
Interest in Web3 gaming or digital economies
Experience with casual or idle game development
What We Offer
Early founding team position in DeGameVerse ecosystem
Equity-based contribution model
Opportunity to publish games under a shared ecosystem
High creative freedom in game design and experimentation
Direct collaboration with core product founder
Important Note
This is an early-stage startup role.
There is no fixed salary at this stage. Compensation is based on equity and long-term ecosystem growth.
How to Apply
Send:
Portfolio / GitHub / game demos
Short intro about your experience
Why you want to build Web3 games
Any previous projects (if available)
DeGameVerse is building a next-generation Web3 gaming ecosystem where developers create games and players play, progress, and earn within a unified platform.
We are building:
▫️ AI-assisted game creation tools
▫️ Web-based casual & idle games
▫️ Player-first reward economy
▫️ Walletless onboarding experience
This is an early-stage startup forming its core founding team.
Role Overview
We are looking for a creative and technically strong Game Developer who can also explore AI-driven game generation and integration.
You will help build engaging web-based games and connect them to the DeGameVerse ecosystem.
This is a builder role, not a traditional employment position.
Responsibilities
Develop simple to mid-level web games (JavaScript / Phaser / Unity WebGL)
Design core gameplay mechanics (progression, rewards, loops)
Integrate games into DeGameVerse platform ecosystem
Work on AI-assisted game creation concepts and prototypes
Handle game logic, scoring, and interaction systems
Collaborate with full-stack developer for platform integration
Optimize games for mobile-first web experience
Requirements
Strong understanding of JavaScript or game development frameworks
Experience building browser-based or mobile-friendly games
Good grasp of game mechanics and player engagement loops
Creative mindset for designing fun and scalable gameplay
Bonus Skills
Experience with Phaser / Unity WebGL / Three.js
Exposure to AI tools (GPT APIs, procedural generation, etc.)
Interest in Web3 gaming or digital economies
Experience with casual or idle game development
What We Offer
Early founding team position in DeGameVerse ecosystem
Equity-based contribution model
Opportunity to publish games under a shared ecosystem
High creative freedom in game design and experimentation
Direct collaboration with core product founder
Important Note
This is an early-stage startup role.
There is no fixed salary at this stage. Compensation is based on equity and long-term ecosystem growth.
How to Apply
Send:
Portfolio / GitHub / game demos
Short intro about your experience
Why you want to build Web3 games
Any previous projects (if available)
DeGameVerse
Full Stack Developer (Core Builder) — Startup
Full time
Remote
About DeGameVerse
DeGameVerse is building a next-generation Web3 gaming platform where developers can create games and players can play, progress, and earn inside a unified ecosystem.
We are focused on:
Walletless onboarding
AI-assisted game creation
Player-first game economy
Mobile-friendly gaming experiencesexperiences
This is an early-stage startup currently building its core founding team.
Role Overview
We are looking for a passionate Full Stack Developer to help build the core infrastructure of DeGameVerse.
You will work directly with the founder to develop the platform architecture, user systems, game hub, and Web3 integrations.
This is not a traditional job position. We are building with a startup mindset and long-term vision.
Responsibilities
Build responsive frontend interfaces using React / Next.js
Develop backend APIs and database systems
Implement authentication and user management
Integrate MPC wallet / Web3 onboarding systems
Create scalable game hub architecture
Optimize platform performance and security
Collaborate on product decisions and feature planning
Requirements
Strong knowledge of React / Next.js
Experience with backend development (Node.js, Firebase, Supabase, etc.)
Understanding of REST APIs and databases
Basic understanding of Web3 concepts
Strong problem-solving skills
Ability to work independently in a startup environment
Bonus Skills
Wallet integration experience
Web3 or blockchain project experience
Multiplayer or gaming platform experience
AI tool integration experience
What We Offer
Early core team position
Equity-based opportunity
Direct impact on product direction
Opportunity to help build a large-scale Web3 gaming ecosystem from the ground up
Important
This is an early-stage startup role.
No fixed salary initially. Compensation will be equity-based until funding or revenue is secured.
DeGameVerse is building a next-generation Web3 gaming platform where developers can create games and players can play, progress, and earn inside a unified ecosystem.
We are focused on:
Walletless onboarding
AI-assisted game creation
Player-first game economy
Mobile-friendly gaming experiencesexperiences
This is an early-stage startup currently building its core founding team.
Role Overview
We are looking for a passionate Full Stack Developer to help build the core infrastructure of DeGameVerse.
You will work directly with the founder to develop the platform architecture, user systems, game hub, and Web3 integrations.
This is not a traditional job position. We are building with a startup mindset and long-term vision.
Responsibilities
Build responsive frontend interfaces using React / Next.js
Develop backend APIs and database systems
Implement authentication and user management
Integrate MPC wallet / Web3 onboarding systems
Create scalable game hub architecture
Optimize platform performance and security
Collaborate on product decisions and feature planning
Requirements
Strong knowledge of React / Next.js
Experience with backend development (Node.js, Firebase, Supabase, etc.)
Understanding of REST APIs and databases
Basic understanding of Web3 concepts
Strong problem-solving skills
Ability to work independently in a startup environment
Bonus Skills
Wallet integration experience
Web3 or blockchain project experience
Multiplayer or gaming platform experience
AI tool integration experience
What We Offer
Early core team position
Equity-based opportunity
Direct impact on product direction
Opportunity to help build a large-scale Web3 gaming ecosystem from the ground up
Important
This is an early-stage startup role.
No fixed salary initially. Compensation will be equity-based until funding or revenue is secured.
Bitrefill
Senior Data Scientist / ML Engineer – Crypto Payments & Lightning Network
Stockholm, Sweden
Stockholm, Sweden
Full time
Remote
About Bitrefill
Bitrefill is the world's leading crypto lifestyle platform. We enable millions of users globally to pay for gift cards, mobile phone refills, and everyday goods using Bitcoin, Lightning Network, and other digital assets. Our long-term goal is to provide everyone with the tools to use crypto as real "digital money" daily — without needing to register for additional services or log into a web platform.
We are now actively building a new product: the Bitrefill crypto card for paying for goods and services in everyday life.
The Role
We are looking for a Senior DS/ML Engineer to help us make data-driven decisions across fraud detection, Lightning Network liquidity optimization, user behavior modeling, and risk scoring for the crypto card.
You won't just build models — you'll help shape the ML infrastructure of a fast-growing crypto-payments startup.
What You'll Do
Fraud & Risk ML — Develop anomaly detection models, transaction scoring for withdrawals, and real-time predictive rules to flag suspicious activity.
Lightning Network optimization — Build models to optimize payment routing, channel liquidity management, and predict channel health.
Crypto card infrastructure — Create credit risk models and user scoring for card issuance without traditional credit history.
LTV & churn prediction — Forecast user behavior to improve retention and conversion, especially in low-crypto-adoption countries.
Product & growth analytics — Develop ML-driven hypotheses for A/B testing and recommendation systems (e.g., which gift cards to offer).
Data pipeline & MLOps — Help build pipelines for training and deploying models to production (alongside engineers).
Requirements
5+ years of experience in Data Science / Machine Learning, ideally in fintech, payments, crypto, or high-throughput transactional systems.
Strong experience building anti-fraud models, time series forecasting (for transactions), LTV predictions, or classification/clustering models.
Python — solid proficiency (pandas, scikit-learn, xgboost/lightgbm; PyTorch/TensorFlow is a plus).
SQL — advanced level.
Experience with Airflow, dbt, or similar ETL/ML pipeline tools.
Understanding of Lightning Network basics (or strong willingness to dive deep within 1–2 weeks).
English — sufficient to discuss ML metrics and business problems fluently.
Big Pluses
Experience with graph models (Node2Vec, GNNs) for transaction chain detection.
Familiarity with blockchain analytics (on-chain data, addresses, transactions).
Experience in credit scoring without traditional credit history.
MLOps skills (Docker, Kubeflow, MLflow, or at least deploying models via FastAPI).
Personal experience using Bitrefill or crypto as a payment tool.
We Offer
Fully remote work from anywhere in the world (with ~4–6 hours overlap with Stockholm time zone).
Opportunity to build an ML system from scratch in a startup that is truly changing how people use crypto.
Competitive salary + equity (tokens) or profit-sharing.
Minimal bureaucracy — maximum responsibility and freedom.
Work with cutting-edge technologies: Lightning Network and crypto cards.
How to Apply
Send your resume and a link to your GitHub / Kaggle / project where you solved a fraud, time series, or risk modeling problem. Mention if you have experience with Lightning or blockchain analytics — if not, just tell us how quickly you can learn new domains.
Bitrefill is the world's leading crypto lifestyle platform. We enable millions of users globally to pay for gift cards, mobile phone refills, and everyday goods using Bitcoin, Lightning Network, and other digital assets. Our long-term goal is to provide everyone with the tools to use crypto as real "digital money" daily — without needing to register for additional services or log into a web platform.
We are now actively building a new product: the Bitrefill crypto card for paying for goods and services in everyday life.
The Role
We are looking for a Senior DS/ML Engineer to help us make data-driven decisions across fraud detection, Lightning Network liquidity optimization, user behavior modeling, and risk scoring for the crypto card.
You won't just build models — you'll help shape the ML infrastructure of a fast-growing crypto-payments startup.
What You'll Do
Fraud & Risk ML — Develop anomaly detection models, transaction scoring for withdrawals, and real-time predictive rules to flag suspicious activity.
Lightning Network optimization — Build models to optimize payment routing, channel liquidity management, and predict channel health.
Crypto card infrastructure — Create credit risk models and user scoring for card issuance without traditional credit history.
LTV & churn prediction — Forecast user behavior to improve retention and conversion, especially in low-crypto-adoption countries.
Product & growth analytics — Develop ML-driven hypotheses for A/B testing and recommendation systems (e.g., which gift cards to offer).
Data pipeline & MLOps — Help build pipelines for training and deploying models to production (alongside engineers).
Requirements
5+ years of experience in Data Science / Machine Learning, ideally in fintech, payments, crypto, or high-throughput transactional systems.
Strong experience building anti-fraud models, time series forecasting (for transactions), LTV predictions, or classification/clustering models.
Python — solid proficiency (pandas, scikit-learn, xgboost/lightgbm; PyTorch/TensorFlow is a plus).
SQL — advanced level.
Experience with Airflow, dbt, or similar ETL/ML pipeline tools.
Understanding of Lightning Network basics (or strong willingness to dive deep within 1–2 weeks).
English — sufficient to discuss ML metrics and business problems fluently.
Big Pluses
Experience with graph models (Node2Vec, GNNs) for transaction chain detection.
Familiarity with blockchain analytics (on-chain data, addresses, transactions).
Experience in credit scoring without traditional credit history.
MLOps skills (Docker, Kubeflow, MLflow, or at least deploying models via FastAPI).
Personal experience using Bitrefill or crypto as a payment tool.
We Offer
Fully remote work from anywhere in the world (with ~4–6 hours overlap with Stockholm time zone).
Opportunity to build an ML system from scratch in a startup that is truly changing how people use crypto.
Competitive salary + equity (tokens) or profit-sharing.
Minimal bureaucracy — maximum responsibility and freedom.
Work with cutting-edge technologies: Lightning Network and crypto cards.
How to Apply
Send your resume and a link to your GitHub / Kaggle / project where you solved a fraud, time series, or risk modeling problem. Mention if you have experience with Lightning or blockchain analytics — if not, just tell us how quickly you can learn new domains.
Payment in Crypto
New Gig Workforce Solutions
Chief Technology Officer (CTO) – Blockchain Gaming Platform
Full time
Remote
We are supporting a well-funded startup building a next-generation blockchain gaming platform powered by AI technology. The company is backed by strong investors and has already launched an initial version of its product. As the platform evolves, the team is rebuilding its technology stack and infrastructure to support scalable on-chain gaming mechanics, digital asset ownership, and advanced blockchain integrations. This role goes far beyond a typical executive position. The client is looking for a Chief Technology Officer (CTO) with deep blockchain expertise and strong leadership capabilities who can define the long-term technical vision, lead engineering execution, and help shape the future direction of the company. The ideal candidate has a hands-on mindset, startup experience, and is passionate about building innovative products in the blockchain gaming space. Responsibilities Define and lead the company’s overall technical vision and engineering strategy Oversee architecture and development of blockchain infrastructure and gaming systemsLead and scale engineering teams across Web3, backend, frontend, DevOps, and AI functions Drive technical decision-making for scalability, security, and product performance Collaborate closely with founders, product teams, and stakeholders on roadmap execution Establish engineering processes, development standards, and technical best practices Guide smart contract architecture and blockchain integrations Support hiring, mentoring, and team growth across technical departments Evaluate emerging technologies and industry trends relevant to blockchain gaming and AIRequirements Strong leadership experience as a CTO, Head of Engineering, or senior technical leader Deep understanding of blockchain ecosystems, Web3 technologies, and smart contractsStrong technical background in modern software development and system architectureExperience managing and scaling engineering teams in startup environments Understanding of cloud infrastructure, DevOps, and scalable distributed systems Experience with React, Node.js, or modern web technologies is a strong plusFamiliarity with gaming, NFT ecosystems, or digital asset platforms is highly preferredStrong communication and decision-making skillsEntrepreneurial mindset with interest in long-term product ownership and company growth Benefits and PerksCompetitive executive compensation package with equity participationHealth, dental, and vision coverage Unlimited PTOPension contributionRemote-friendly environment with flexibilityExpense reimbursement for home internet and phoneOngoing professional development and leadership growth opportunitiesOpportunity to shape the future of a blockchain gaming platform at an early stage Hiring Process Introductory conversationStrategic and technical discussions with leadership teamFinal alignment and offer discussions
Payment in Crypto