Senior Agent Engineer (Langchain)

Focused; Chicago (IL); On-site; USD 120,000 - 170,000; Full time

Job summary

Focused in Chicago is seeking a hands-on senior full stack engineer to drive AI-powered software for clients. You will collaborate across design, product, and client teams to deliver production-ready solutions using LangChain, LLMs, and modern web tech.

The role requires in-office presence three days a week, up to 20% travel within the United States, and a commitment to TDD, pairing, and scalable architectures while mentoring teammates and raising engineering standards.

Qualifications

• Hands-on, full stack engineer with agile delivery experience.

Responsibilities

• Build AI-enabled apps using LangChain and LLMs for client outcomes.
• Lead end-to-end delivery from backend to web UI.
• Pair program daily with teammates and clients.
• Practice TDD and refactoring to keep code reliable.
• Guide architecture for scalability and performance.
• Collaborate with designers, PMs, and stakeholders.
• Coach developers through pairing and mentoring.
• Influence technical direction across client orgs and internal teams.
• Experiment with GenAI patterns and share learnings.

Skills

LangChain

LangGraph

LangSmith

Full stack

Pair programming

TDD

Python

Node.js

Java

React

Next.js

Tools

LangChain

OpenAI APIs

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 being in the Chicago office three days per week and up to 20% travel within the United States.
• Focused is unable to sponsor or take over sponsorship of the employment Visa process at this time.
• The Chicago base salary range for this role is $120,000 - $170,000.

Voluntary Self-Identification

For government reporting purposes, we ask candidates to respond to the below self-identification survey.Completion of the form is entirely voluntary. Whatever your decision, it will not be considered in the hiringprocess or thereafter. Any information that you do provide will be recorded and maintained in aconfidential file.

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.

If you believe you belong to any of the categories of protected veterans listed below, please indicate by making the appropriate selection.As a government contractor subject to the Vietnam Era Veterans Readjustment Assistance Act (VEVRAA), we request this information in order to measurethe effectiveness of the outreach and positive recruitment efforts we undertake pursuant to VEVRAA. Classification of protected categoriesis as follows:

A "disabled veteran" is one of the following: a veteran of the U.S. military, ground, naval or air service who is entitled to compensation (or who but for the receipt of military retired pay would be entitled to compensation) under laws administered by the Secretary of Veterans Affairs; or a person who was discharged or released from active duty because of a service-connected disability.

A "recently separated veteran" means any veteran during the three-year period beginning on the date of such veteran's discharge or release from active duty in the U.S. military, ground, naval, or air service.

An "active duty wartime or campaign badge veteran" means a veteran who served on active duty in the U.S. military, ground, naval or air service during a war, or in a campaign or expedition for which a campaign badge has been authorized under the laws administered by the Department of Defense.

An "Armed forces service medal veteran" means a veteran who, while serving on active duty in the U.S. military, ground, naval or air service, participated in a United States military operation for which an Armed Forces service medal was awarded pursuant to Executive Order 12985.