Senior full-stack engineer (business workflow platforms) - 21906

Senior Full-Stack Engineer — Business Workflow Platforms

Location: Remote · Must work core hours in U.S. time zones

Employment Type: Full-time · Available as contract (Talent on Demand)

Works with: Lead Developer, alongside the client's in-house engineering team

About the Company

We are a rapidly growing U.S.-based, AI-native product studio. We take companies from idea to launch-ready software in weeks, then partner with them through fast, two-week sprints to build and scale production systems. We have shipped 200+ products and hold a high bar on engineering quality even as we move quickly. Our team is fully distributed, and every engineer owns meaningful, visible work.

About the Role

We are building workflow-heavy business software for one of our clients, inside an existing production codebase shared with the client's own engineering team. We need a full-stack engineer who can safely extend a live system — adding tables, permissions, and workflows without breaking what is already running — and ship four to five features per two-week sprint. This is an AI-first environment. Tools like Cursor, Claude Code, and coding agents write most of the first draft; you direct them, review every diff, and own what ships. Speed here comes from tooling and judgment, not from skipping tests, reviews, or acceptance criteria. We are looking for a genuine engineer who uses AI to go faster, not someone who leans on it in place of craft.

Key Responsibilities

• Backend & Data Model: Extend an existing production backend and data model — adding tables, permissions, and workflows without breaking live features. Write data migrations from legacy sources, with reconciliation and duplicate review.
• Workflow & Business Logic: Build server-side business rules: state machines, approval gates, independent review steps, and versioned records that keep full history. Build a shared task engine with owners, backups, due dates, deduplication, and completion evidence.
• Security & Access Control: Implement role-based access control scoped by company and assignment, enforced at both the database and the API. Build an append-only audit log, stale-write protection, and idempotent endpoints so retries never create duplicates. Build secure file upload and storage with versioning, malware scanning, and time-limited access links.
• Integrations & APIs: Integrate email and SMS providers with templates, delivery tracking, retries, and opt-out handling. Design and build the sync and submission APIs that the companion mobile app depends on.
• Web Interface & Tooling: Build work queues, bulk assignment tools, and dashboards in the web interface.
• Reliability & Delivery: Add monitoring and alerting, run access reviews and restore tests, and load test before launch. Work through branches, code review, and feature flags alongside a second engineering team in the same repo.

Required Qualifications

• 4+ years building and shipping full-stack web applications to production.
• Strong relational database skills: schema design, migrations, query performance, and data integrity.
• Experience with role-based access control, audit logging, and multi-tenant data isolation.
• Comfort reading and extending a large codebase you did not write, adapting quickly to its stack and conventions.
• Experience building workflow-heavy business software: queues, state machines, approvals, and tasks.
• Experience with idempotent APIs, retries, and concurrency (stale-write protection, duplicate prevention).
• Integration experience with email and SMS providers and file storage.
• Daily, hands-on use of AI coding tools (Cursor, Claude Code, or similar) on production work, with a workflow you can walk us through.
• A track record of shipping fast without lowering the bar: automated tests, CI, and reviews that catch what AI gets wrong.
• Strong written and spoken English — clear pull requests, precise questions, and the ability to explain tradeoffs to a client team.
• Able to work core hours in U.S. time zones.

Preferred Qualifications

• Experience with heavily regulated workflows.
• Experience setting up agent workflows, project rules, or custom prompts that make a whole team faster with AI.
• Experience migrating messy legacy data.
• Experience working inside another team's codebase as an outside vendor.
• Spanish (the platform is bilingual, though it is not required).

Ideal Candidate Profile

You are a strong engineer who is fast because you have mastered your tools, including AI — not because you cut corners. You are comfortable being dropped into a live codebase you did not write, and you make changes that do not break things. You think in systems: permissions, edge cases, concurrency, and what happens on a retry. You write clearly, ask precise questions, and can hold your own in front of a client's engineering team. You would rather own a problem end to end than wait for a fully specified ticket.

Why Join Us

You will build real production systems used by real businesses, ship visible work every sprint, and work inside a lean, high-caliber team that trusts your judgment. If you want to work at the frontier of AI-assisted engineering without lowering your standards, this is that seat.