Senior Full Stack Engineer

SUMMARY:
This is the business''s first engineering hire. You will join a team of three who own the data pipelines, client relationships and private markets domain, while taking ownership of the application, including the portal, authentication, tenant isolation, infrastructure and security.

POSITION INFO:
Senior Full Stack Engineer Own the development of a multi-tenant investor reporting platform, from architecture and authentication through to infrastructure, security and production delivery. Remote (South Africa) | 9:00-18:00 SAST | R80,000 per month, negotiable ABOUT OUR CLIENT Our client is a London-based advisory firm working with private markets fund managers across investor reporting, data and AI. The business is building a multi-tenant investor reporting platform that enables fund managers to upload quarterly data, validate it and provide investors with a secure view of fund performance. THE ROLE: SENIOR FULL STACK ENGINEER This is the business''s first engineering hire. You will join a team of three who own the data pipelines, client relationships and private markets domain, while taking ownership of the application, including the portal, authentication, tenant isolation, infrastructure and security. With an MVP due by the end of the year, you will make architecture decisions with limited oversight and challenge the current plan where necessary. There is no legacy codebase or existing engineering team, giving you responsibility for setting standards, selecting tooling and shaping how the product is built. The current prototype stack is not fixed. Part of the role is determining what works and what should change. KEY RESPONSIBILITIES Build the client-facing portal using Next.js and TypeScript on AWS (eu-west-2), taking the current prototype through to a production product. Build authentication and authorisation in Auth0, including organisations, roles and invite flows, with SSO for enterprise clients planned later. Implement end-to-end tenant isolation, with access enforced at the Snowflake database layer and tested automatically. Ensure fund managers can access all their funds while investors can access only their own. Build the upload flow for Excel and PDF submissions using an embedded CSVbox importer, with files landing in S3 as versioned and immutable before loading into Snowflake. Integrate and white-label third-party components, including Evidence.dev dashboards, to provide clients with one product and one login. Implement infrastructure as code, CI\/CD, secrets management and audit logging. Build the controls required for SOC 2 readiness. Make architecture and tooling decisions with limited oversight. Set engineering standards and shape how the product is built. Work directly with the team responsible for client relationships, data pipelines and the private markets domain. FIRST 90 DAYS Deliver a production-grade authentication and tenant isolation model that is tested and documented. Deliver the upload-to-dashboard flow end to end using real client data. Put infrastructure as code and CI\/CD in place so nothing depends on one person''s laptop. Provide a written assessment of what you would change in the current architecture and why. ABOUT YOU 5+ years of experience building production web applications, including at least one multi-tenant B2B product where you built the authentication and access model. Production experience with Next.js App Router and TypeScript. Experience with Auth0 or an equivalent identity provider in a multi-tenant environment. AWS experience covering S3, IAM, secrets, hosting and CI\/CD. Experience with Terraform or a similar infrastructure-as-code tool. Strong understanding of application security fundamentals. Experience with a penetration test or SOC 2 process. Fluent with AI coding tools such as Claude Code, Cursor or similar as part of your daily workflow, with a clear understanding of where they help and where they do not. Comfortable working independently within a very small team, documenting your work and making decisions without a senior engineer checking them. Useful but not required: Python skills sufficient to read and extend openpyxl and Pandera validation code. Experience with Snowflake, dbt or Evidence.dev. Experience within financial services or other regulated-data environments. Private markets knowledge; the team will teach you what you need.