Senior Backend Engineer

About 8fig:

At 8fig, we’re building the future of eCommerce funding. Our AI-powered platform analyzes real-time sales and banking data to offer personalized, flexible growth plans tailored to each business. By combining smart capital with powerful planning tools, we empower eCommerce businesses to scale sustainably and strategically - on their terms.

About the role:

We’re looking for a Senior Backend Engineer to help shape how we build software with AI. You’ll join a small team with the opportunity to shape both the product and how we build it. In this hands-on role, you’ll use Claude Code as your primary development tool and work closely with product and business teams to turn customer needs into reliable fintech solutions. You’ll combine engineering judgment with ownership of software that moves real money.

Main Responsibilities:

• Deliver features end to end using AI coding agents such as Claude Code, Codex or GitHub Copilot., from task breakdown and agent execution to reviewing, correcting and merging code.
• Review, refactor and harden agent-generated TypeScript to ensure correctness, readability and security.
• Write clear technical specifications for agents and verify generated code before submitting it for review.
• Build internal tools and workflows using the Claude Agent SDK and API, including Slack bots, data lookups and R&D operations automation.
• Define guardrails for agent access to production data, secrets and payment flows.
• Track agent output quality, rework rate and development cycle time, and share effective practices with the team.

Requirements

What You Bring:

• 5+ years building production backend systems with strong TypeScript and Node.js skills.
• Daily use of Claude Code or a comparable AI coding agent in production development, with examples to share.
• Strong code review skills to spot subtle bugs, unhandled edge cases, and unnecessary complexity in agent-generated code.
• Functional programming proficiency: pure functions, immutability, composition, and explicit side effects.
• Strong SQL and MySQL skills.
• AWS experience with Lambda, RDS, S3, and Secrets Manager.
• Sound judgment on when to use AI agents and when to write code directly.
• Clear written English for prompts, technical specifications, and PR descriptions.

Advantages:

• Experience configuring Claude Code with custom skills, hooks, subagents, and MCP servers.
• Experience building tools and workflows with the Claude Agent SDK or API.
• Familiarity with fintech, payment flows, and secure handling of sensitive data.
• Hands-on experience with Amazon Redshift.

If you find this opportunity interesting and it seems like a good fit, don’t hesitate to reach out - we’re looking for you!