Mid Level Fullstack Engineer (React/Front End focus)

Colossus Technologies Group · Massachusetts, United States
LinkedIn

Posted

Jun 24, 2026 (Jun 24)

Seniority

Mid-Level

Work Model

Not Specified

Type

Not Specified

Category

Frontend

Salary

Not specified

Skills

AWS Azure CI/CD Docker DynamoDB Express GCP Git GraphQL HTML JavaScript LLM MongoDB MySQL Next.js Node.js React TypeScript

Description

We’re partnering with a high-growth SaaS company building AI-powered products and are looking for a Mid-level Fullstack Software Engineer to join a small, fast-moving team. This role is front-end heavy (React/TypeScript) with meaningful exposure to backend services in Node.js/Express/Nest. You’ll ship features end-to-end, collaborate closely with product/design, and help scale a modern AI-driven web application. What you’ll do Build and maintain production React/TypeScript frontends, translating product requirements into clean, reusable components and flows Implement responsive UI and state management, integrating with REST/JSON or GraphQL APIs and handling auth, error states, and performance optimizations Contribute to backend services using Node.js with Express and/or Nest.js, including API endpoints, business logic, and integrations with third-party services and internal AI services Work on AI-powered product features (e.g., integrating existing AI/ML services, orchestrating prompts, wiring up model outputs into UX) in collaboration with senior engineers Write maintainable, well-tested code, participate in code reviews, and help improve our engineering standards, tooling, and CI/CD practices Collaborate cross-functionally with Product, Design, and other engineers to scope work, estimate effort, and deliver features in iterative releases What we’re looking for 2+ years of professional software engineering experience building web applications in a production environment Strong hands-on experience with React in production (hooks, component composition, state management, performance optimizations Experience with TypeScript, modern JavaScript (ES6+), HTML, and CS Practical backend experience with Node.js plus at least one of: Express or Nest.js (building APIs, working with middleware, integrating data sources Experience working on AI-related products is strongly preferred (this could be integrating third-party LLM APIs, building AI-assisted workflows, or contributing to ML/GenAI-backed features Familiarity with relational or NoSQL databases and basic data modeling (e.g., Postgres, MySQL, MongoDB, DynamoDB Comfortable using Git and collaborating in a modern dev workflow (pull requests, code reviews, feature branches, CI/CD Strong communication skills and the ability to work effectively with a distributed, cross-functional team Nice to have Experience with Next.js or similar React frameworks Exposure to cloud platforms (AWS, GCP, or Azure) and containerization (Docker) Familiarity with design systems, component libraries, and front-end performance profiling Prior experience in a startup or fast-paced product environment, especially shipping AI or data-heavy features Why this opportunity Work on real, user-facing AI features rather than pure infrastructure or internal tools Join a small, focused engineering team where your impact on product direction and technical decisions is visible Modern tech stack centered around React/TypeScript and Node.js, with room to grow deeper on both front and backend.