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