Senior Fullstack Engineer

Role at a Glance

We're seeking a talented Full-Stack Engineer to play a key role in architecting and implementing user-facing components of the Paystand open banking network. As a member of our dynamic team, you'll collaborate closely with product owners, designers, and fellow engineers to craft web applications that redefine user interactions.

AI-First Engineering Expectations

Paystand is an AI-first organization. As a FullStack Engineer, you are expected to:

We believe in augmenting human engineering with intelligence. As an AI-first organization, our expectations for this role reflect that commitment:

• Leverage AI-powered coding assistants to accelerate development velocity and maintain high code quality.
• Architect systems with AI integration in mind, ensuring our 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.
• Drive technical innovation by actively integrating the latest AI development frameworks and practices into our stack.

Role and Key Responsibilities

• 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 other engineers to build the best user experience, ensuring high standards of quality and performance.
• Ensure best practices in code quality, security, and performance.
• Participate in and influence all phases of the development lifecycle, including system analysis, design, coding, testing, debugging, and documentation.
• Advocate for and implement continuous improvement in the development processes and practices.

Requirements & Qualifications

• Builder Experience
• 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.
• Able 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.
• Comfortable making progress without a fully prescribed specification while knowing when alignment, deeper analysis, or broader architectural review is needed.
• AI-Native Development:
• 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.
• Architecture and Engineering:
• 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 or other high-trust systems, including authorization, data protection, auditability, failure recovery, and idempotent processing.
• Full-Stack Product Development:
• 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—not simply implementation from a design file.
• Willingness and ability to learn unfamiliar frameworks or technologies when they are the right choice for the product.
• Cloud, Scaling, and Delivery:
• 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.
• Comfortable owning software after release, including production health, incident response, root-cause analysis, and continuous improvement.
• Product Ownership and Leadership:
• 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.
• Able 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.

Bonus Skills

• 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 is valuable but not required.
• Contributions to open-source software, technical communities, or other evidence of active building and continued learning.

Perks

• Salary + competitive equity in a high-growth-stage startup.
• Generous PTO (vacations) and sick days.
• Free snacks and paid lunch in the office.
• Major Medical Health Insurance.
• Food Vouchers.
• Stock Options.
• Your own equipment and tools.
• Opportunity for advancement and growth in a rapidly expanding team.
• Mentorship, learning and education programs.
• Smart, high-achievers, motivated team that likes to have fun.
• Mission-driven culture, where your work matters.