We are looking for a Senior Front-End Engineer to help us build smart, compelling and intuitive clientserver-side applications for our products. This is an exciting role for an engineer to come in and develop the major client-side features in a rapidly growing, fast-paced startup. We build for product excellence, focus on smart solutions through innovation and technology, have an amazing growth-oriented culture, and love to solve complex problems. If you share the same values, you should consider joining us in our efforts to achieve the extraordinary! You will be primarily responsible for creating and maintaining complex client-side applications for our mobile or desktop products. Some tasks will require understanding and modifying server-side APIs written in a strongly-typed web application framework. You will work with Product, Design, Backend, and Quality Assurance to develop scalable, rock-solid, production ready features. You will be expected to iterate rapidly while delivering high-quality output. Integrate 3rd party APIs (Cloud elements) Architect Solutions Architect efficient and reusable front-end solutions driving complex web applications Revamp Participate in re-imagining our client-side application architecture Problem-solve Solve challenges on the edge of old and new front-end technologies Develop Manage Develop and maintain sufficient test coverage for all features Maximize Efficiency Optimize performance heavy parts of existing applications Guide Mentor less experienced developers Qualifications Very strong understanding of core JavaScript without third-party libraries andor frameworks especially prototypical inheritance and the orchestration of multiple asynchronous API calls via callbacks, promises, and asyncawait. Very strong understanding of ES6+ additions to JavaScript and their relationship to pre-ES6 concepts Experience creating or maintaining JSON Web APIs backed by relational databases in any strongly-typed back-end development framework. Should be comfortable with MVC, Dependency Injection and ORM concepts Experience writing Unit Tests (Server or Client Side) Familiarity with browser-based web storage APIs such as WebSQL, IndexedDB, localStorage S., M.S., or Ph.D. in Computer Science or equivalent Knowledge of commonly used algorithms and data structures 5+ years of JavaScript experience Heavy use of core, framework agnostic JavaScript Building reusable UI components Interaction with external APIs and 3rd party integrations Solving UI-related performance problems