Strong Middle/Senior Full-Stack Engineer

Job description

Design, develop, and maintain end-to-end product features across Back-end and Front-end systems Build scalable services, APIs, and workflow-driven solutions supporting core business operations Collaborate closely with Product, Design, and Engineering teams to define requirements and shape product direction Translate operational and business processes into intuitive and scalable software experiences Participate in architecture discussions, technical planning, and code reviews Own features throughout the full development lifecycle from discovery to deployment Evaluate technical decisions from both engineering and user-impact perspectives Improve product quality, scalability, developer experience, and operational efficiency Work effectively in a startup environment with evolving priorities and changing requirements Contribute proactively to technical and product discussions and suggest improvements when needed At least 5 years of commercial software engineering experience Strong proficiency in TypeScript with solid Back-end development expertise Experience designing and delivering production-ready product features end-to-end Strong experience with relational databases, preferably PostgreSQL Experience developing scalable services and APIs Experience working with AWS cloud services Understanding of modern software architecture and engineering best practices Ability to work independently and take ownership of technical solutions Strong problem-solving skills and ability to work with ambiguity Excellent communication and collaboration skills Product-minded approach to software development Upper-Intermediate English level or higher Experience participating in code reviews and technical discussions Ability to balance technical quality with business and user needs WILL BE A PLUS Experience with NestJS Experience with Next.js and React Experience with Temporal or other workflow orchestration platforms Experience working in startup or high-growth product environments Experience in fintech products or platforms Background in payment systems, billing, invoicing, or transaction-focused products PERSONAL PROFILE Proactive and ownership-driven mindset Comfortable working in environments with changing priorities and evolving requirements Strong collaboration and communication skills Ability to understand business context beyond implementation details User- and product-oriented approach to decision-making Self-sufficient and adaptable team player Join a fast-growing fintech product where engineering decisions directly shape business operations and user experience. We are looking for a Strong Middle/Senior Full-Stack Engineer with a Back-end focus to help build scalable onboarding and workflow automation solutions for modern businesses. This is a fully remote opportunity for specialists located in LATAM who enjoy solving ambiguous challenges, taking ownership of features end-to-end, and collaborating closely with Product and Design teams in a startup-like environment. We at Sigma Software value engineers who think beyond implementation details and actively contribute to product evolution. Here, you will have the opportunity to influence architecture decisions, improve operational workflows, and work on meaningful customer-facing functionality with a high level of autonomy. CUSTOMER Our Customer is a fast-growing fintech startup transforming how businesses manage financial and operational workflows. The company develops scalable digital products that replace fragmented and manual operational processes with automated and intuitive experiences. Working in a fast-paced environment, the team combines strong product ownership with rapid iteration and close collaboration across Engineering, Product, and Design. PROJECT You will join the Team responsible for building scalable onboarding experiences and workflow-driven functionality integrated into the core product platform. The team focuses on replacing internal tools and manual operations with customer-facing solutions that improve operational efficiency and user experience. A significant part of the role involves understanding complex business processes, evaluating existing workflows, and translating them into scalable product functionality while balancing technical quality, usability, and business impact.