Senior Fullstack Engineer

As a Senior Fullstack Engineer at Paystand, you'll architect and implement user-facing components of the blockchain-enabled B2B payments network. You'll collaborate with product owners, designers, and engineers to build web applications that redefine how enterprises manage payments and receivables on-chain.

What you'll do

• Lead the architecture and implementation of user-facing parts of Paystand's systems
• Design and develop reusable libraries and frameworks that support complex web applications
• Provide technical leadership and mentorship to other engineers
• Collaborate with product owners, designers, and engineers to build the best user experience while ensuring high standards of quality and performance
• Ensure best practices in code quality, security, and performance across the stack
• Participate in all phases of the development lifecycle, including system analysis, design, coding, testing, debugging, and documentation
• Advocate for and implement continuous improvement in development processes and practices
• Leverage AI-powered coding assistants to accelerate development velocity and maintain high code quality
• Architect systems with AI integration in mind, ensuring web applications can seamlessly interface with machine learning models and data pipelines
• Proactively identify and automate manual engineering workflows such as testing, documentation, and infrastructure management using AI tools

What you bring

• 7+ years of professional software engineering experience with a track record of independently delivering meaningful products or major capabilities from concept through production
• Strong full-stack capability and the judgment to work across frontend, backend, data, infrastructure, and integrations as the product requires
• Ability to move from an ambiguous business problem to a practical solution: clarify the problem, evaluate tradeoffs, establish an architecture, build the product, deploy it, and improve it using production feedback
• Fluency with AI-assisted and agent-led software development using tools such as Claude, Claude Code, OpenAI Codex, or comparable platforms
• Experience using AI throughout the engineering lifecycle, not only for code generation but also for discovery, architecture, implementation planning, testing, debugging, documentation, code review, and operational analysis
• Ability to provide agents with effective context, decompose work into verifiable tasks, evaluate generated solutions critically, and maintain responsibility for correctness, security, and maintainability
• Practical understanding of building AI-enabled product capabilities using model APIs, structured outputs, tool calling, retrieval, evaluations, guardrails, and human-in-the-loop workflows
• Strong engineering judgment about where AI increases leverage and where deterministic software, conventional automation, or direct human review is more appropriate
• Strong understanding of modern application architecture, including modular system design, API design, asynchronous and event-driven processing, data consistency, caching, and integration patterns
• Demonstrated ability to design systems that can evolve and scale without introducing unnecessary complexity
• Experience making and documenting architectural decisions based on reliability, security, performance, cost, maintainability, and speed of delivery
• Practical experience with relational databases, data modeling, distributed systems, observability, automated testing, and production troubleshooting
• Familiarity with secure engineering practices appropriate for financial systems, including authorization, data protection, auditability, failure recovery, and idempotent processing
• Strong experience with at least one modern frontend ecosystem such as React, Next.js, Vue, or Angular, including component architecture, state management, accessibility, performance, and responsive design
• Strong experience with at least one production backend ecosystem such as Node.js/TypeScript, Python, Java, Go, Elixir, or a comparable framework
• Ability to design clear APIs and data contracts and integrate with internal services, third-party platforms, and legacy systems
• Product-minded approach to frontend development, with attention to workflows, usability, edge cases, and the complete customer experience
• Willingness and ability to learn unfamiliar frameworks or technologies when they are the right choice for the product
• Hands-on experience designing, deploying, and operating production systems on AWS or Google Cloud
• Working knowledge of Cloudflare capabilities such as DNS, CDN, edge security, traffic management, Workers, or related edge infrastructure
• Experience with containers, infrastructure as code, CI/CD, environment management, secrets management, and automated deployment practices
• Understanding of horizontal scaling, load management, queues, caching, database scaling, fault tolerance, disaster recovery, and multi-region considerations
• Ability to build useful observability into a product through logs, metrics, traces, alerts, and business-level workflow monitoring
• Comfort owning software after release, including production health, incident response, root-cause analysis, and continuous improvement
• Product mindset with the ability to co-own a product area alongside a product manager, from customer problem and business outcome through technical delivery and adoption
• Ability to challenge assumptions, identify simpler solutions, define incremental releases, and balance immediate customer value with long-term technical health
• Strong written and verbal communication, including the ability to explain technical decisions and tradeoffs to engineering, product, design, operations, and business stakeholders
• Demonstrated technical leadership through architecture, execution, code review, mentorship, and raising engineering standards
• High degree of ownership, curiosity, pragmatism, and follow-through

Nice to have

• Experience building payment, fintech, accounting, ERP, banking, or other transaction-intensive products
• Experience with high-integrity workflows involving money movement, reconciliation, ledgers, approvals, or external financial integrations
• Experience building or operating AI agents and agentic workflows in production, including evaluation, monitoring, security, and cost management
• Familiarity with workflow orchestration, event streaming, or durable execution technologies
• Experience with blockchain, digital assets, smart contracts, or decentralized systems
• Contributions to open-source software, technical communities, or other evidence of active building and continued learning

What we offer

• Generous PTO and sick leave
• Free snacks and paid lunches in the office
• Major Medical Health Insurance
• Food vouchers and savings funds
• Stock options
• Best-in-class tools and equipment
• Endless growth opportunities as the company rapidly expands

About Paystand

Paystand is the world's leading blockchain-enabled B2B payments network, transforming commercial finance into a zero-fee, software-driven, and open ecosystem. Recognized as a CNBC/Statista 2026 World's Top Fintech company, Paystand serves more than one million payors with $20+ billion in volume moved, offering a full-stack platform including agentic AI, USDb stablecoin, AR/AP solutions, and a non-profit arm advancing financial democratization through Bitcoin and blockchain.