New opportunity

Engineer III - AI

Frost Bank · San Antonio, United States of America

About this role

Frost Bank seeks an Engineer III - AI in San Antonio, TX - One Frost, to design intelligent systems and workflows using autonomous agents and large language model (LLM) decision-making. The role leads technical work on AI reliability, bias mitigation, and drift detection for enterprise AI systems.

Responsibilities

  • Architect agentic workflows and lead design sessions covering agent loops, tool orchestration, and task planning.
  • Work with product and design leaders to define outcomes and performance metrics. Evaluate agent behavior for fairness, reliability, explainability, and safety.
  • Improve agentic-system performance through caching, throttling, and fallback strategies. Mentor engineers on LLM prompting, agent decomposition, and tool design.

Required qualifications

  • Bachelor’s degree in Computer Science, Data Science, or a related field, and at least 4 years of experience with enterprise-grade AI/ML systems.
  • Deep understanding of event-driven design, API orchestration, prompt engineering, tool orchestration, planner/verifier roles, and system modularity; strong skills in memory and context handling and agent-loop optimization.
  • Experience leading teams applying LLMs and autonomous agents to real-world problems; strong experience with Python, FastAPI, LangChain, vector databases, and agent-loop architectures.
  • Excellent written and verbal communication and proficiency with Microsoft computer applications.

Preferred qualifications include creating reusable agent libraries or co-pilots, contributing to open-source AI frameworks or tooling, and experience with LangGraph, CrewAI, or AutoGen. The posting lists medical, dental, vision, long-term disability and life insurance; 401(k) matching; holidays and paid time off; tuition reimbursement; health and wellness programs; and a referral bonus program.

For full details about this role, click “Apply on company site” to view the employer’s original posting.

Skills for this role

AI agentsLarge language modelsAgent loop architecturesTool orchestrationTask planningPrompt engineeringMemory and context handlingEvent-driven designAPI orchestrationSystem modularityPythonFastAPILangChainVector databasesAI reliabilityBias mitigationDrift detectionAI fairnessExplainabilityAI safetyCachingThrottlingFallback strategiesLangGraphCrewAIAutoGenCommunicationTeam leadership

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Get interview-ready for this role

A focused preparation guide, built around this job’s responsibilities and requirements.

✦ AI-generated guide
Preparation suggestions, not the employer’s actual interview questions. Always check the original posting for current requirements.
01

Understand the role

What matters most

  • Architect agentic workflows

    The role designs intelligent systems using LLM decision-making and leads sessions on agent loops, tool orchestration, and task planning. Prepare to explain architecture decisions at the workflow level, including planner/verifier roles and modularity.

  • Lead trustworthy AI evaluation

    The posting assigns technical leadership for reliability, bias mitigation, and drift detection, plus evaluation of fairness, explainability, and safety. Prepare to describe how these concerns inform system design and evaluation.

  • Define outcomes and improve performance

    The engineer works with product and design leaders on outcomes and performance metrics, then optimizes agentic systems using caching, throttling, and fallbacks. Prepare to connect technical choices to measurable behavior.

  • Guide engineering execution

    This is a system-design role that also mentors engineers on prompting, agent decomposition, and tool design. Prepare to discuss how you lead design decisions and communicate them across engineering, product, and design.

Likely challenges to think through

  • Balancing agent autonomy with safeguards

    Likely preparation hypothesis: more flexible agent loops can make behavior harder to explain or keep reliable. Be ready to reason through where verification, tool boundaries, and behavior evaluation belong in a design; the posting does not prescribe a particular approach.

  • Optimizing without masking failures

    Likely preparation hypothesis: caching and throttling can improve performance, while fallbacks can preserve service, but each may affect response quality or visibility into failures. Prepare to explain how you would assess those trade-offs against the defined metrics.

  • Turning broad AI principles into usable measures

    Likely preparation hypothesis: fairness, safety, explainability, and reliability may pull in different directions when product outcomes are defined. Prepare to discuss how you would work with product and design leaders to choose and interpret metrics without assuming Frost has specified thresholds.

03

Practice your answers

Technical practice

How would you architect an agent loop for a complex task?

What to coverSuggested preparation: Explain how the agent plans, selects tools, checks results, and decides when to stop. Discuss where planner and verifier roles improve reliability and where they add complexity.

How would you design tool orchestration across APIs and events?

What to coverSuggested preparation: Describe clear tool interfaces, event-driven handoffs, and handling of failed or repeated calls. Explain how modularity helps isolate tool failures without making the workflow harder to reason about.

How would you manage prompts, memory, and context in an agent?

What to coverSuggested preparation: Discuss what information to retain, retrieve, or discard as an agent works through a task. Address how you would test whether prompt or context changes improve decisions rather than introduce new errors.

How would Python, FastAPI, LangChain, and a vector database fit into an agentic system?

What to coverSuggested preparation: Sketch the responsibilities of the API layer, orchestration code, and retrieval component without assuming a particular product use case. Explain how you would test the boundaries between them and assess whether retrieval is helping.

How would you diagnose an agent whose results become less reliable over time?

What to coverSuggested preparation: Describe how you would separate changes in inputs, retrieval, tools, and agent decisions when investigating drift. Explain what evidence would justify an alert, a workflow change, or further observation.

How would you evaluate an agent for fairness, explainability, and safety?

What to coverSuggested preparation: Describe representative test cases, failure categories, and review of agent decisions and tool use. Discuss trade-offs between useful explanations and the risk of treating an agent's stated reasoning as proof of correctness.

When would you use caching, throttling, or fallbacks in an agent workflow?

What to coverSuggested preparation: Explain the performance problem each strategy addresses and how it could affect answer quality or reliability. Include how you would measure whether the change improves the overall workflow.

How would you define outcomes and performance metrics with product and design leaders?

What to coverSuggested preparation: Start with the intended user outcome, then propose measures of agent effectiveness and failure, not just speed. Explain how you would resolve a trade-off when an optimization improves one metric but weakens reliability or safety.

How would you decide what belongs in a reusable agent component?

What to coverSuggested preparation: Discuss stable interfaces for prompts, tools, or workflow steps and how to avoid hiding task-specific behavior inside a shared library. Reusable agent libraries are preferred experience in the posting, so treat a library design as a practice scenario rather than an assumed project.

Behavioural practice

Tell me about a time you led a technical design discussion with competing approaches.

What to coverSuggested preparation: Use situation, action, and result to show how you framed the decision, heard objections, and reached a workable design. A discussion involving workflow architecture or tool orchestration would be especially relevant to the stated duties.

Describe a time you aligned technical work with product or design goals.

What to coverSuggested preparation: Use situation, action, and result to explain how you clarified the desired outcome and agreed on useful measures. Show how you handled a trade-off or changed course based on evidence.

Tell me about a time you mentored engineers on a complex technical practice.

What to coverSuggested preparation: Use situation, action, and result to show what guidance you gave, how you adapted it to the engineers' needs, and what changed. Prompting, agent decomposition, or tool design are relevant topics if they match your actual experience.

Describe a time you addressed a reliability, bias, or safety concern.

What to coverSuggested preparation: Use situation, action, and result to explain how you established the concern, communicated its implications, and evaluated a response. Be precise about your own role and the evidence behind the outcome.

Tell me about a time you explained a complex technical problem to non-specialists.

What to coverSuggested preparation: Use situation, action, and result to show how you made the issue and proposed solution understandable without overstating certainty. Highlight how the communication helped others make a decision.

02

Sharpen your knowledge

Topics to prepare

  • Agent-loop architecture

    Required understanding: agent loops, task planning, tool orchestration, planner/verifier roles, and modularity. As revision, sketch a small agent workflow and explain how it plans, invokes a tool, verifies a result, and handles a failed step.

  • Event-driven design and API orchestration

    The posting calls for deep understanding of both. As revision, draw an event-to-API workflow and identify component boundaries, error paths, and where an agent waits for or reacts to results.

  • Prompt, memory, and context design

    Prompt engineering and memory and context handling are stated requirements. As revision, compare two ways to supply context for a multi-step task and explain the effect of missing, stale, or excessive context.

  • Agent evaluation and drift

    The role leads work on reliability, bias mitigation, and drift detection, and evaluates fairness, explainability, and safety. As revision, define a small set of test cases and explain what evidence would reveal a regression or change in behavior.

  • Outcomes and performance tradeoffs

    The role defines outcomes and performance metrics with product and design leaders and optimizes with caching, throttling, and fallbacks. As revision, choose metrics for a hypothetical agent workflow and explain when each optimization could help or harm those outcomes.

Skills to revise

  • Build a small agent-service prototype

    Strong experience with Python, FastAPI, LangChain, vector databases, and agent-loop architectures is required. For practice, build a toy FastAPI endpoint that runs a LangChain-based loop using a vector database, then trace its decisions and failure handling. This is a preparation exercise, not a described Frost project.

  • Test prompts and context handling

    The posting requires prompt engineering and agent-loop optimization. For practice, run the same task with varied prompts and available context; record tool choices, verification results, and where the loop stops or repeats.

  • Evaluate agent behavior

    The role calls for evaluating fairness, reliability, explainability, and safety. For practice, create a compact test set with normal, ambiguous, and failure cases; document observed behavior and a proposed bias or reliability mitigation.

  • Apply performance safeguards

    Caching, throttling, and fallback strategies are explicit responsibilities. For practice, add each to a toy workflow, trigger a slow or failed tool response, and compare behavior and chosen performance metrics before and after.

  • Lead a design review

    The role drives design sessions, collaborates on metrics, and mentors engineers. For practice, present an agent-loop diagram, defend its tool boundaries and success measures, then give specific feedback on a sample prompt or tool design.

04

Your preparation checklist

  • Prepare an agent-system walkthrough

    If you have a relevant project, make a one-page account of the problem, your design decisions, the agent loop, tool use, outcomes, and your individual contribution. The posting emphasizes system design and real-world LLM applications.

  • Sketch an agent workflow

    As a practice exercise, draw an event-driven workflow with API and tool orchestration, task planning, planner/verifier roles, and memory and context handling. Be ready to explain failure paths and modularity choices.

  • Draft an evaluation plan

    Prepare a sample evaluation matrix for fairness, reliability, explainability, safety, bias mitigation, and drift detection. Label it as a proposed approach, and show how you would agree on outcomes and metrics with product and design leaders.

  • Work through performance tradeoffs

    Create a short design note comparing caching, throttling, and fallback strategies for an agent loop, including what each might improve and what behavior would need monitoring.

  • Organize evidence for the stated qualifications

    Make a factual inventory of relevant education and enterprise AI/ML work, plus examples involving Python, FastAPI, LangChain, vector databases, prompting, and communication. Include preferred tools or reusable libraries only if you have direct evidence.

  • Rehearse a technical-leadership example

    Prepare a concise account, if available, of leading a design session or mentoring engineers on prompting, agent decomposition, or tool design; identify the decision made and how you communicated it.

  • Write questions for Frost Bank

    Ask which agent workflows this role would design first, how product and design leaders define success, and how the team currently evaluates reliability, fairness, and drift.

AI-generated from the job information · Prepared Sep 30, 2026 (UTC)Useful preparation, not a guarantee of eligibility or an offer.

Availability last checked: Nov 4, 2026. Status can change after a check; confirm on the employer’s website. Report an issue · Our checking policy

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