Senior Software Engineer – Customer Portal, Auth & Billing

The Opportunity

We are seeking a Senior Software 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.

We value people who make things happen through their own enthusiasm, rather than waiting for managers to tell them what to do. Here, individual contributors hold the highest status — they are the driving force behind the company’s progress. You’ll work alongside top professionals in an environment that celebrates curiosity, creativity, and results. This is a rare opportunity to join an early-stage company founded by Andrew Filev (founder of a unicorn startup) — to help scale it into a thriving, world-changing business. Together, we’re shaping the future of software development — closing the gap between idea and reality, and influencing not only how code is written, but how progress happens across every field that depends on software.

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?

• Shape the Future of Software Creation: We’re not just improving how developers write code — we’re redefining how ideas turn into reality. By closing the gap between concept and execution, we’re creating tools that will influence every industry that relies on software.
• Massive Impact, Real Ownership: At Zencoder, you’ll have full visibility into how your work moves the product and the company forward. You’ll ship features that matter, see the immediate impact of your decisions, and get feedback directly from users — fast.
• ICs Are the Core: Individual Contributors are the highest-status role at Zencoder. Our culture celebrates those who lead by doing — who create momentum, inspire others, and turn ideas into shipped products.
• High-Caliber Team & Founder: Work alongside exceptional AI and software engineers, and learn directly from Andrew Filev, founder