Senior Software Engineer – Backend & AWS Integrations

About the Role We're looking for a Senior Software Engineer with strong backend and AWS experience to help build and evolve a payroll giving platform from the ground up. You'll focus on designing and implementing APIs that connect third-party services with internal AWS components, supporting payroll integrations, financial management, and money movement. You'll join a small, hands-on team and work closely with the Lead Engineer / Architect and Product stakeholders. This role is ideal for someone who can take ownership of components end to end, contribute to architectural decisions, and move comfortably between implementation, problem-solving, and collaboration. Experience with payroll systems is helpful, but strong API development and AWS integration experience are more important. We value engineers who communicate openly, ask thoughtful questions, use AI-assisted development tools effectively, and take initiative to deliver reliable, maintainable solutions. Responsibilities • Design, build, and implement HTTP APIs that connect third-party services with internal AWS components. • Develop and extend integrations that support payroll connections and the onboarding of additional employer and payroll partners, primarily through the Finch API abstraction. • Build backend components for the platform's financial management and money movement capabilities, including integrations with external financial services such as Modern Treasury. • Develop, maintain, and improve AWS-based services using Infrastructure as Code and AWS CDK. • Contribute to the evolution of the platform's architecture and implementation approach, applying AWS Well-Architected Framework principles with a focus on reliability, supportability, and cost effectiveness. • Use AI-assisted development tools to accelerate code analysis, implementation, code reviews, testing, and validation. • Take ownership of assigned components from clarifying requirements and identifying solutions through implementation and successful delivery. • Collaborate with Product, Program Management, Partnerships, and technical team members, translating technical needs into clear language for both technical and non-technical stakeholders. • Help ensure that the platform and its integrations are maintainable, supportable, and ready to scale as new partners and capabilities are introduced. Requirements • Senior-level, hands-on experience building backend services and designing, developing, and integrating APIs. • Strong practical experience with AWS, including building backend services in an AWS environment. • Experience with AWS Lambda and Infrastructure as Code; familiarity with AWS CDK is expected. • Experience integrating third-party APIs and connecting external services to internal systems or infrastructure. • Working knowledge of Python and/or TypeScript. The team is flexible on the specific backend language, provided you have strong AWS and API development experience. • Ability to understand an existing architecture and build components that fit into it. • Experience using AI-assisted development tools in a practical engineering workflow, particularly for coding, code analysis, testing, and validation. • Strong written and verbal English communication skills (C1 level). • Ability to work independently, manage ambiguity, ask questions early, and take responsibility for delivering high-quality work. • Experience applying the AWS Well-Architected Framework in production systems Nice to Have • Experience with payroll platforms, payroll systems, or payroll integrations; familiarity with Finch is a plus. • Experience with banking, payment processing, money movement, financial infrastructure, ledgers, or reconciliation; familiarity with Modern Treasury is a plus. • Knowledge of identity and authentication protocols such as OIDC or SAML 2.0. • Experience with AWS CodePipeline or other CI/CD workflows, GitHub, and application monitoring tools such as Sentry. • Familiarity with React or experience supporting frontend portals and dashboards. • Hands-on experience with Claude Code, Claude, or similar AI-assisted engineering tools. Soft Skills • Self-starting and curious, with the confidence to ask questions instead of making assumptions or working silently with incomplete information. • Highly accountable and ownership-driven; you follow tasks through, find the right resources, and proactively work through blockers. • A strong communicator who can explain technical concepts and requirements clearly to both engineers and non-technical stakeholders. • Collaborative and engaged, with a willingness to contribute ideas and participate in architectural discussions rather than simply wait for instructions. • Comfortable challenging assumptions constructively and explaining why an alternative approach may lead to a better outcome. • Adaptable and pragmatic, able to work effectively in a small team where priorities and requirements may evolve. Other • Full-time engagement (160 hours per month). • Remote position open to candidates based in Latin America. • English proficiency: C1