Fullstack Engineer; m​/f​/d

Hello, I am Servesh, Co-founder and CTO at Kayzen, and I am looking for a Fullstack Engineer to join our Console team. You may not have heard of Kayzen before.

Kayzen is a mobile demand-side platform (DSP) dedicated to democratizing programmatic advertising. We enable leading apps, agencies, media buyers, and brands to run programmatic customer acquisition, retargeting, and brand performance campaigns through its self-serve and managed service options. Built on the three core pillars of performance, transparency, and control, Kayzen powers the world’s best mobile marketing teams with bespoke solutions that fuel business growth and deliver a competitive advantage.

With an unprecedented scale of 160B+ daily ad requests from 1.6B+ unique users worldwide, we serve up to 1B+ ads per day in 180 countries. Kayzen is accessible through our APIs and user interface.

The Console team owns the user-facing applications and interfaces that power the Kayzen platform — from our self-serve campaign management dashboard and real-time reporting suite to internal tooling used by our managed service teams. We work closely with product managers, designers, backend engineers, and data teams to deliver seamless, high-performance experiences. We are responsible for some of the most impactful work at Kayzen, including:

• The Console which is the face of Kayzen we are very proud of.
• Complex features which surface a lot of backend infrastructure via console
• Almost 100% uptime with very well planned & executed project management

We are looking for a coding-first Fullstack Engineer who thrives on turning complex product requirements into high-performance UIs. You should be comfortable working across the stack, contributing to architecture discussions, and be an early adopter of AI-assisted engineering such as Claude Code, Cursor, Copilot in your daily coding workflow. This role is a strong individual contributor position with room to grow into deeper technical ownership over time.

• Core responsibilities
• Design, build, and maintain high-quality features across the Fullstack stack, from UI to API integration
• Write clean, well-tested, production-ready code and actively participate in code reviews
• Collaborate closely with Product, Design, QA, and Backend teams to deliver cohesive, user-centric features
• Contribute to technical decisions around architecture, tooling, and best practices within the team
• Take ownership of features end to end, from planning through deployment and monitoring
• Hands‑on AI Implementation
• Integrate AI-powered coding agents and automated LLM-based testing into your daily development cycle
• Contribute to building AI‑First UI patterns, working alongside the LLM Platform team on generative, prompt‑driven interfaces
• Stay current with emerging AI‑assisted development tools and bring relevant ones back to the team
• Project & Execution Management
• Break down assigned product requirements into clear, actionable engineering tasks
• Deliver work reliably within sprint commitments, flagging blockers or scope changes early
• Balance new feature delivery with addressing technical debt in the codebase you work on

• Solid expertise in at least one major framework (React, Angular, or Vue) and its ecosystem
• Experience building data‑heavy UIs, ideally including real‑time data visualization
• Good grasp of Fullstack performance optimization, including bundle size, rendering, lazy loading, and caching strategies
• Experience with state management patterns (Redux, MobX, Zustand, or similar)
• Working knowledge of Fullstack testing methodologies, unit, integration, and end‑to‑end (Jest, Cypress, Playwright, or similar)
• Comfortable working with design systems and shared component libraries
• Experience using AI‑assisted development tools (Claude Code) to boost engineering productivity
• Experience contributing to Fullstack architecture decisions on production applications
• Solid understanding of APIs, RESTful services, GraphQL, and system design fundamentals
• Ability to give and receive constructive feedback through code reviews
• Good communication skills, able to explain technical…