Senior Full Stack Java Developer Jobs in Charleston, WV

A1 is building a proactive AI smart assistant for everyday users to bring intelligence to conversations, errands, organising and workflows.

Our product focuses on achieving high reliability for long-running workflows, persistent context, and real-world task completion. The system must handle multi-step reasoning, interact with external tools, and remain reliable despite non-deterministic model behavior.

You are the engineering backbone of the internal tools team. Building and maintaining the platforms that every team in the company relies on. Your work directly increases organizational efficiency and enables teams to move faster.

You’ll own systems end-to-end, from scoping and architecture through production deployment and iteration, connecting multiple business systems into a seamless, reliable internal ecosystem.

Build & Ship

• Design, build, and maintain internal platforms and tools that serve People, Finance, Ops, Sales, and Engineering teams.

• Own features end-to-end: requirements, architecture, implementation, testing, deployment, and monitoring.

• Write clean, well-tested, production-grade code. You hold yourself to the same bar as customer-facing products.

Architecture & Integration

• Build API-first integrations across the internal ecosystem — connecting HRIS, CRM, finance platforms, knowledge management, and developer tools into a coherent stack.

• Design for reliability, performance, and scale — what you build today must hold as the company grows 5–10x.

• Eliminate data silos. Build clean data pipelines that maintain a single source of truth across systems.

• Own your services in production: monitoring, alerting, incident response, and post-mortems.

AI & Automation

• Build AI/LLM-powered features into internal workflows — automating approvals, knowledge retrieval, reporting, content generation, and operational processes.

• Move fast from prototype to production. You know the difference between a demo and a system that works at scale.

• Stay current on emerging AI capabilities and proactively identify where they unlock step-change improvements in internal productivity.

Collaboration & Influence

• Work directly with business stakeholders to understand pain points and translate them into technical solutions. You don’t wait for a spec — you help shape it.

• Pair with and mentor junior engineers. Raise the technical bar through code reviews, design reviews, and leading by example.

• Influence technical direction: propose architectural improvements, challenge assumptions, and drive best practices across the team.

Must-Have

• 5+ years of professional software engineering experience, with meaningful time spent building internal tools, platforms, or business systems.

• Strong full-stack or backend engineering skills. Proficient in at least one of: Python, Go, TypeScript/Node.js, or Java.

• Solid understanding of cloud infrastructure (GCP/AWS/Azure), containerisation (Docker/Kubernetes), CI/CD pipelines, and modern DevOps practices.

• Hands-on experience building and maintaining API integrations between third-party SaaS platforms (e.g., Workday, Salesforce, Slack, NetSuite).

• Strong data fundamentals: relational databases, data modelling, ETL/ELT pipelines, and working knowledge of SQL.

• Comfort with ambiguity. You can take a vague business problem, break it down, and deliver a working solution without heavy hand-holding.

• Clear communicator who can explain technical tradeoffs to non-technical stakeholders.

Nice-to-Have

• Experience with workflow orchestration tools (Temporal, Airflow, Prefect) or integration platforms (Workato, Tray.io, MuleSoft).

• Frontend experience with React, Next.js, or equivalent modern frameworks.

• Familiarity with HRIS, ERP, or people systems data models and processes.

• Experience at a high-growth or AI-native company.

• Contributions to developer experience tooling, CLIs, or internal SDKs.

• Experience building or integrating AI/LLM-powered features — not just experimenting, but shipping to real users.

The best products today in the world were built by small, world class teams. We are a high talent density and hands-on team. We make decisions collectively, move at rapid speed, striking a balance between shipping high quality work and learning. Joining our team requires the ability to bring structure, exercise judgment, and execute independently. Our goal is to put in hands of our users a truly magical product

If there appears to be a fit, we'll reach out to schedule 3, but no more than 4 interviews.

Applications are evaluated by our technical team members. Interviews will be conducted via virtual meetings and/or onsite.

We value transparency and efficiency, so expect a prompt decision. If you've demonstrated the exceptional skills and mindset we're looking for, the process to offer may be shorter.