FullStack Engineer (Customer Portal, Auth & Billing)

We are seeking a Senior FullStack Engineer to take full ownership of our customer portal — a key product surface that’s still in its early stages but already built on solid foundations. In this role, you’ll lead its evolution end-to-end, shaping how our customers interact with the platform and also defining patterns, tackling complex edge cases, and driving best practices across product, design, and engineering.

You should be confident working with Next.js, experienced in integrating authentication providers like Auth0 or WorkOS, and have hands-on expertise with Stripe for billing and subscription workflows. Our UI is built with ShadCN, based on Radix UI and TailwindCSS — familiarity with any of these is a strong plus.

This is a unique opportunity to join an early-stage company led by the founder of a unicorn startup, Andrew Filev, and help scale it into a thriving, innovative business.

Key Responsibilities

• Take end-to-end ownership of our customer portal's architecture, development, and scaling, including billing flows, user management, and settings.

• Design and implement new features, refactor existing code for maintainability, and ensure production readiness across the stack.

• Raise the bar for engineering quality by driving best practices in testing, observability, CI/CD, and code structure.

Essential Qualifications

• 10+ years of experience in software engineering, including deep expertise in TypeScript, React, and Next.js.

• Proven ownership of complex frontend applications — ideally, customer-facing portals or dashboards.

• Experience with authentication systems (e.g., Auth0, WorkOS or other OAuth2 implementations).

• Hands-on Stripe integration experience.

• Familiarity with ShadCN, Radix UI, TailwindCSS, or equivalents.

• User experience with advanced AI assistants (e.g., Cursor, Claude Code, WindSurf).

Why Join Zencoder?

• Impact: Gen AI will change how companies develop software in the next two years. Be at the frontier of that AI work, building a category-leading product in a huge market. You will have an everyday opportunity to innovate.

• Growth potential: Thrive in a high-growth AI startup combining personal and career growth.

• High Talent Density: Collaborate daily with our experienced AI engineers, software engineers, and founder, Andrew Filev.

• Equity: Align your success with ours by participating in our equity plan.

• Flexibility: We hire globally, prioritizing talent over location. Work where you’re most productive and comfortable.