Senior Agent Engineer (Langchain)

Focused; United States; Remote; USD 120,000 - 170,000; Full time

Job summary

Focused, a fast-moving software partner, is seeking a hands-on senior full-stack engineer to design and deliver AI-powered applications for diverse clients using LangChain and OpenAI APIs.

You will lead end-to-end delivery across the stack, pair with teammates daily, mentor developers, and help evolve architectural standards while traveling up to 30% across the United States.

Qualifications

• Hands-on full-stack engineer with a proven track record in collaborative, agile environments.
• Experience with LangChain (or similar agent frameworks) and architecting AI-native systems.
• Experience leading engineering teams and mentoring other developers.

Responsibilities

• Build AI-enabled applications using LangChain and OpenAI APIs.
• Lead end-to-end delivery across the stack from backend to frontend.
• Pair program daily with teammates and clients to share knowledge and improve code quality.
• Practice TDD and refactoring to keep code reliable and maintainable.
• Guide architectural decisions to support scalability, observability, and performance.
• Collaborate with designers, product managers, and stakeholders to deliver value.

Skills

Full stack engineering

LangChain experience

Team leadership / mentoring

TDD / pairing

Multi-language: Python, Node.js, Java,

React / Next.js

AI/NLP development

Tools

LangChain

OpenAI APIs

React

FastAPI

Job description

At Focused, we move quickly to deliver quality software that achieves client outcomes and meets their customer’s needs. We strategically partner with our clients to leverage our expertise in design and software, while our clients bring their own domain expertise. We work with a variety of clients from different industries, collaborating as we get new products to market, modernizing legacy systems, or helping teams learn the skills they need to be successful.

Our values:

• Listen first We are experts in product practices but life long learners in the domain of our customers. We research, collaborate, and understand.
• Learn why We ask questions and talk to users to understand problem spaces, objectives, and goals, which allows us to deeply invest and drive towards the outcomes of our clients.
• Love your craft We love diving into a variety of domains and solving problems. We take pride in delivering value, in communicating progress, and guiding our clients to success.

At Focused, our Engineers are both practitioners and experts in their craft. This role would play a crucial role in shaping and implementing engineering best practices and ensuring the successful delivery of complex software projects. With clients, we develop trust and influence - we are unintimidated and unintimidating. With colleagues, we set the standard for how we deliver success for clients.

What would you be doing?

• Build AI-enabled applications leveraging LangChain and LLMs to deliver meaningful, production-ready outcomes for clients.
• Deep expertise in LangChain, LangGraph and LangSmith
• Lead teams through end-to-end delivery across the stack, from backend services to modern web UIs.
• Pair program daily with teammates and clients to share knowledge, improve code quality, and grow together.
• Practice TDD and continuous refactoring to ensure code is reliable, maintainable, and understandable.
• Guide architecture decisions to support scalability, observability, and performance.
• Collaborate closely with designers, product managers, and stakeholders to continuously deliver valuable software.
• Coach developers on the team through pairing, mentoring, and modeling healthy engineering culture.
• Influence technical direction beyond the team, working across client orgs and Focused’s internal practices to share lessons, shape approaches, and raise the collective bar.
• Stay curious through experimenting with new patterns in the GenAI space, share what works (and what doesn’t), and help evolve how we build AI-powered software.

We are excited about you, because you:

• You’re a hands-on, full stack engineer with a strong track record of delivering software in collaborative, agile environments.
• You’ve worked with LangChain (or similar agentic frameworks), and understand how to architect AI-native systems responsibly and effectively.
• You have experience leading engineering teams and feel confident mentoring and supporting other developers.
• You believe that code quality matters, and that TDD and pairing help build better systems and stronger teams.
• You’ve worked across multiple languages or frameworks (e.g., Python, Node, Java, React, Next.js) and are pragmatic about tool selection.
• You’re excited about what’s happening in the AI space but stay focused on delivering value.
• You have experience navigating complex organizations, building bridges across functions, and helping teams adopt modern development practices.
• You’re as comfortable in the code as you are in a client meeting and can translate technical risks and wins into language anyone can understand.
• You love to share what you’re learning and make the team around you better.

If you had worked at Focused over the last 3 months you may have:

• Paired with a teammate to build a document Q&A system using LangChain and OpenAI APIs
• Helped design an architecture that integrates LLM agents into a legacy enterprise workflow
• Refactored a flaky test suite to support continuous delivery with confidence
• Mentored a junior dev through their first pairing and TDD session
• Built and deployed a full stack GenAI MVP with a React frontend and FastAPI backend
• Facilitated an architecture spike to evaluate vector database options for semantic search
• Contributed a new section to our internal AI playbook
• Helped write this job req

What to know before you apply:

• This role will require up to 30% travel within the United States.
• Focused is unable to sponsor or take over sponsorship of the employment Visa process at this time.
• The base salary range for this role is $120,000 - $170,000.

As set forth in Focused’s Equal Employment Opportunity policy,we do not discriminate on the basis of any protected group status under any applicable law.