Senior Backend Engineer

Location

San Francisco, CA

On-site five days per week preferred; can flex to three days per week in-office for exceptional candidates.

Compensation

$170,000 – $230,000 Base + Competitive Equity

Visa

Open to visa transfers, including H-1B and OPT.

Company Stage

Growth-Stage / Venture-Backed Technology Company

Industry

FinTech, B2B Payments, Financial Infrastructure, SaaS, Payments, Data Infrastructure, Enterprise Technology

About the Company

Our client is building a modern B2B payments platform designed to bring the B2B economy online through seamless, automated payment workflows.

The company is building category-defining financial infrastructure powered by clean, reliable data systems that help businesses automate complex B2B payment processes.

The platform sits at the intersection of payments, data infrastructure, and enterprise software, with backend systems directly powering critical payment decisions and customer experiences.

The engineering organization is relatively lean, creating an environment where individual engineers have significant ownership and direct impact on the product.

This is a high-agency engineering environment where engineers are expected to take ambiguous real-world problems, define the right solution, and own projects from initial design through production deployment.

As a Senior Backend Engineer, you'll work on core data and payments infrastructure while building reliable systems, APIs, internal tools, and services that directly impact business outcomes.

The ideal candidate combines strong backend engineering fundamentals with high ownership, product judgment, and the ability to operate effectively in ambiguous startup environments.

What You'll Do

• Build and own production backend systems powering core data and payments infrastructure
• Design scalable backend services using TypeScript and Node.js
• Build reliable APIs, services, data models, and contracts used across the organization
• Develop systems where correctness, reliability, and data integrity are critical
• Build and improve core payment infrastructure and workflows
• Work on data infrastructure supporting payment decisions and customer experiences
• Develop internal tools that help teams review data and understand system decisions
• Build tooling that enables internal teams to operate more efficiently without sacrificing quality
• Own ambiguous technical projects from problem definition through production deployment
• Identify problems independently and propose effective technical solutions
• Break large technical problems into production-ready increments
• Ship production systems quickly while maintaining engineering quality
• Improve backend system reliability, latency, and correctness
• Design systems that can scale with rapidly increasing transaction and data volumes
• Build robust APIs and services consumed by internal and external systems
• Design and maintain backend data models and service contracts
• Collaborate closely with Product and other engineering teams
• Translate product requirements and business problems into technical solutions
• Make architecture and engineering tradeoff decisions independently
• Take ownership of technical decisions rather than waiting for detailed specifications
• Monitor and improve system performance and reliability
• Identify technical risks and proactively address them
• Build systems that are maintainable, observable, and resilient
• Work closely with stakeholders to understand business impact and customer needs
• Contribute to engineering standards and best practices
• Help establish scalable patterns for backend development
• Operate as a highly autonomous engineer within a lean engineering organization
• Take projects from initial concept through design, implementation, launch, and iteration
• Help shape the technical direction of core payments and data infrastructure

Ideal Candidate Background

Experience Requirements

• 5+ years of professional backend software engineering experience
• Strong experience building production backend systems
• Experience working with TypeScript and Node.js
• Experience designing APIs and backend services
• Experience with SQL and relational databases
• Experience with PostgreSQL preferred
• Experience working with AWS or similar cloud infrastructure
• Experience building data-intensive or transaction-heavy systems
• Experience working on payments, financial infrastructure, fintech, or other high-correctness systems preferred
• Experience owning projects end-to-end
• Experience operating in ambiguous and rapidly changing environments
• Strong startup or high-growth technology company experience preferred
• Experience working in lean engineering organizations
• Experience collaborating closely with Product and cross-functional teams
• Strong understanding of backend architecture and distributed systems
• Experience building reliable and scalable production systems
• Strong debugging and technical problem-solving ability
• Experience making technical decisions independently
• Demonstrated ability to deliver production software with limited oversight
• Experience balancing speed, reliability, and correctness
• Strong product engineering mindset
• Ability to connect technical decisions to business and customer outcomes

Technical Requirements

• Strong TypeScript experience
• Strong Node.js backend development experience
• Strong SQL fundamentals
• Experience with PostgreSQL or similar relational databases
• Experience designing REST APIs
• Strong backend service architecture knowledge
• Experience working with AWS
• Experience with production cloud infrastructure
• Strong understanding of data modeling
• Experience designing service contracts and APIs
• Experience building distributed or highly available backend systems
• Strong understanding of reliability and fault tolerance
• Experience optimizing backend latency and performance
• Experience working with high-volume data systems
• Strong understanding of database performance and query optimization
• Experience building internal tooling
• Experience with data infrastructure preferred
• Experience with Snowflake or modern data platforms preferred
• Experience building payment systems or financial infrastructure preferred
• Strong testing and production engineering practices
• Experience monitoring and debugging production systems
• Strong system design fundamentals
• Ability to make architecture tradeoffs based on scalability, reliability, and business requirements
• Ability to write clean, maintainable, production-quality code
• Strong understanding of software engineering best practices
• Ability to independently design and implement backend systems

Education

• Bachelor's degree preferred
• Computer Science, Engineering, Mathematics, or related technical disciplines preferred
• Strong technical academic background is a plus
• Exceptional professional engineering experience can compensate for academic pedigree

Soft Skills

• High ownership mentality
• Strong agency and independence
• Comfortable operating without detailed specifications
• Strong problem-solving ability
• Strong product intuition
• Business-oriented engineering mindset
• Comfortable working through ambiguity
• Bias toward action
• Strong communication skills
• Ability to explain technical decisions clearly
• Strong collaboration skills
• Comfortable working with Product and cross-functional stakeholders
• Strong judgment around technical tradeoffs
• High attention to detail
• Strong sense of accountability
• Comfortable making decisions with incomplete information
• Ability to balance speed with reliability
• Customer-oriented mindset
• Strong execution ability
• Comfortable owning projects from start to finish
• Proactive approach to identifying problems
• Low-ego and collaborative working style
• Comfortable in lean engineering organizations
• Excited by high-impact, high-responsibility environments
• Strong learning mentality
• Comfortable working in a fast-moving startup environment
• Able to work effectively on-site in San Francisco
• Willingness to work five days per week in-office, with flexibility for exceptional candidates

Compensation & Benefits

• Base Salary: $170,000 – $230,000
• Competitive equity package
• Opportunity to build core infrastructure for a modern B2B payments platform
• High ownership over critical backend systems
• Direct impact on payment infrastructure and customer experiences
• Opportunity to work on complex data and financial systems
• Strong exposure to payments, fintech, and financial infrastructure
• Opportunity to work in a lean, high-agency engineering environment
• Significant technical ownership and autonomy
• Opportunity to shape backend architecture and engineering practices
• Fast-moving startup environment
• Opportunity to work closely with senior technical leadership
• Visa transfer support, including H-1B and OPT where applicable
• San Francisco-based engineering environment

Why Join

This is an opportunity to join a high-growth financial technology company building modern infrastructure for the B2B economy.

As a Senior Backend Engineer, you'll work on systems that sit directly at the heart of payments, data, and financial workflows. Your engineering decisions will directly affect system reliability, payment correctness, and customer experience.

The role offers significant ownership because the engineering organization is lean and the problems are complex. You'll be expected to take ambiguous problems, define the approach, build the solution, and own it through production.

You'll have the opportunity to work across backend infrastructure, payments, data systems, APIs, internal tooling, and reliability while collaborating closely with product and business stakeholders.

If you enjoy high-agency engineering, solving messy real-world problems, building reliable production systems, and owning projects from zero to production, this role offers significant technical scope and impact.