Reviewed by Dr. Dmytro Nasyrov, Founder and CTO
AI Agent Development Company
Pharos Production delivers custom AI agent development services for enterprises and startups.
- Product and engineering leaders evaluating an agent vs a direct LLM call for a specific workflow
- CTOs planning agent observability, evaluation sets, guardrails and rollback procedures
- Operations teams with manual multi-step workflows considering AI agent automation
- CFOs budgeting for AI agent MVPs and ongoing prompt and eval maintenance
- 25+ AI projects delivered
- 90+ engineers
- 90+ Clutch reviews
Aligned with these frameworks. Audit reports and certifications available on request.
Reviewed by Dmytro Nasyrov
Founder and CTO
23+ years in custom software development. Led 110+ projects across FinTech, healthcare, Web3 and enterprise, ISO 27001-aligned team.
What is AI agent development?
Authoritative citations 12 sources
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NIST
NIST AI Risk Management Framework (AI RMF 1.0) defines the govern-map-measure-manage lifecycle for trustworthy AI including agentic systems
nist.gov
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OWASP
OWASP Top 10 for Large Language Model Applications (2025) lists prompt injection, insecure output handling and excessive agency as top agent risks
owasp.org
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a16z
Andreessen Horowitz reports 60% of enterprise AI deployments now include at least one agentic component, up from 9% in early 2024
a16z.com
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OpenAI
OpenAI function calling and Assistants API documentation describe structured tool use as the recommended pattern for production agents
platform.openai.com
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Anthropic
Anthropic Claude tool use guide recommends schema-validated structured output and parallel tool calls for reliable agent loops
docs.anthropic.com
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LangChain
LangChain concepts documentation on agents establishes the eval-harness plus observability plus guardrail pattern used across LangSmith deployments
python.langchain.com
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arXiv
ReAct paper (Yao et al., 2023) established the reason-act-observe loop as the foundation of modern tool-using agents
arxiv.org
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arXiv
Reflexion paper (Shinn et al., 2023) demonstrated self-correction loops improving agent task completion by 20-30 points across benchmarks
arxiv.org
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Gartner
Gartner predicts that by 2028, 33% of enterprise software applications will include agentic AI, up from less than 1% in 2024
gartner.com 2024
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HHS
HHS guidance on artificial intelligence under HIPAA requires audit logging, access controls and de-identification for any PHI processed by AI agents
hhs.gov
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Stanford HAI
Stanford AI Index documents that agentic benchmarks (SWE-bench, WebArena, AgentBench) have become primary reliability signals for production LLM systems
aiindex.stanford.edu
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Google DeepMind
Google DeepMind research on a responsible path to AGI emphasises reward hacking and specification gaming as core failure modes requiring guardrails in production
deepmind.google
- Single-prompt LLM features where direct OpenAI/Anthropic SDK usage is cleaner than an agent framework
- Agents without an evaluation set tied to business outcomes
- Use cases where deterministic rules engines would be cheaper and fully auditable
- Real-time systems with sub-100ms latency budgets that LLM inference cannot meet
- Projects with no plan for prompt versioning, drift monitoring or rollback
Agent runtime architecture
How our AI agents think, act and log
The loop every production agent we ship runs on: router, planner, tools, evaluator, guardrail and audit log. Evaluator can retry via the planner or escalate to a human.
AI agent development at Pharos Production at a glance
- Agents shipped: 15+ production AI agents since 2023 (customer support, document Q&A, multi-agent ops, copilots)
- Stack: LangChain, LlamaIndex, DSPy, CrewAI, OpenAI Agents SDK, OpenAI Assistants API, Anthropic Claude, Vertex AI, AWS Bedrock
- Eval discipline: Every agent ships with a >150-question evaluation set tied to business outcomes; refreshed monthly
- Pricing: Pilot agent $60,000-$120,000; production multi-agent system $240,000-$680,000; enterprise platform $510,000-$1,600,000
- Timeline: Discovery 2-3 weeks; agent MVP 6-10 weeks; multi-agent system with monitoring 4-6 months
- Quality gates: Eval set, shadow-mode validation, citation tracking, structured output validation, audit logging, rollback
- Compliance: ISO 27001 and SOC 2 aligned controls on the delivery pipeline; HIPAA de-identification plus VPC-isolated inference for healthcare agents; GDPR and EU AI Act data residency with right-to-explanation logging; PCI DSS tokenization before the LLM ever sees card data
- Honest scope: We recommend direct LLM APIs for single-prompt features and decline agents without an evaluation set
Custom AI agent vs single-prompt LLM call: which is better?
Custom agents shine on multi-step reasoning, tool use and self-correction, while direct LLM calls (OpenAI/Anthropic SDK) are cleaner and cheaper for single-shot completions. According to a 2024 a16z report, 60% of enterprise AI deployments now include at least one agentic component - but the same report notes that 45% of those deployments would have been better served by a simpler direct call.
| Factor | Custom AI agent | Direct LLM API call |
|---|---|---|
| Reasoning steps | Multi-step planning, tool use, self-correction | Single completion; no tool use unless wrapped manually |
| Tool integration | Native tool calling with structured output validation | Manual function-calling wrapper required for each tool |
| State management | Conversation memory, intermediate state, audit log | Stateless; you manage history |
| Latency | 2-15s typical depending on step count | 0.5-3s typical for single completion |
| Cost per request | $0.05-$0.50 typical depending on step count and model | $0.001-$0.05 per call |
| Determinism | Lower; agent can choose different paths | Higher; same input → same output (with temperature=0) |
| Eval complexity | High; need to test multi-step reasoning paths | Low; test single input/output pairs |
| Best fit | Multi-step workflows, tool orchestration, complex Q&A, copilots | Classification, summarization, structured extraction, single-shot generation |
How we build agents that hold up in production
AI agent projects follow Pharos Verified Delivery with agent-specific gates: discovery defines goal, tool surface and evaluation set; build runs shadow-mode evaluation against human baselines; production readiness includes guardrails, audit logging, drift detection and rollback procedures; support includes prompt versioning, monthly eval refresh and ongoing drift monitoring.
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Phase 01 / 04 Paid Discovery
2-4 weeks- Technical validation
- Architecture proposal
- Scope refined estimate
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Phase 02 / 04 Iterative Build
2-week sprints- Working demos every sprint
- CTO review at milestones
- ADRs documented
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Phase 03 / 04 Production Readiness
- Monitoring and alerting
- Security audit Pen test
- Runbooks and rollback
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Phase 04 / 04 Support
Ongoing- Security patches
- Performance tuning
- 4h SLA response
Pharos Verified Delivery applied to 70+ production applications since 2013
Agents shipping real work
Three agent engagements where we measured accuracy against human baselines before routing real traffic. Client names anonymized under NDA with industry, region and engagement stage preserved. Metrics verified against client telemetry and post-launch production instrumentation.
12 full-time agents handling 8,000 tickets per week. Average response time 4.2 hours. Tier-1 questions consumed 70% of agent capacity.
Custom AI agent deflects 62% of tier-1 tickets[2] with 91% customer satisfaction. Agents now focus on complex cases. Response time on remaining tickets dropped to 28 minutes.
We started with a 200-question evaluation set built from real ticket history, ran the agent in shadow-mode for 3 weeks against human responses and only routed live traffic once accuracy beat the human baseline on tier-1 categories.
Junior attorneys spent 6-8 hours per case reviewing precedent documents. Inconsistent citations across the team.
RAG system over 50,000 case documents with 3-second response time. Citation precision 94%[9] verified against ground truth. Junior attorney research time cut by 75%.
Built on a private vector store with citation tracking back to source paragraphs. Every answer ships with a verifiable footnote so partners can audit any response in under 30 seconds.
Manual orchestration of 6 internal tools for finance ops. 14-day month-end close. Three full-time analysts.
Multi-agent system with finance specialist, data extractor, validator and reporter. Month-end close in 3 days[8] with full audit trail. Analysts redeployed to higher-value forecasting work.
Each agent has a narrow tool surface and a structured handoff protocol. Every action is logged with the full prompt, intermediate state and final tool call, so finance can replay and audit any close-cycle step on demand.
Client names anonymized under NDA. Full case studies at /cases/.
When an AI agent is not the answer
We decline roughly 30% of RFPs we receive. Forcing a bad fit costs both sides 3-6 months and damages outcomes. Here is how we think about scope:
- Single-prompt features where a direct LLM API call is cleaner than an agent framework
- Use cases solvable by deterministic rules engines at 1/100th the cost
- Workflows requiring zero-error guarantees on individual actions (medical dosing, financial settlement)
- Real-time systems with sub-100ms latency budgets
- Projects with no plan for prompt versioning, drift monitoring or rollback
Agents shine when the workflow needs reasoning over multiple steps, tool use, error recovery or routing across specialized capabilities. For single-shot tasks, a direct OpenAI or Anthropic call is cleaner, faster and cheaper. For deterministic rules, a rules engine is auditable and 100x cheaper. We start every AI engagement by asking "can this be solved without an agent?" If yes, we say so.
Background reading before you decide
State of AI Development Costs 2026 Original Pharos research on AI project costs based on 25+ delivered systems including agents, RAG and multi-agent architectures. Continue readingPharos AI agent portfolio
Pharos AI agent delivery portfolio observations, 2023-2026
Ranges we consistently see across 12+ production AI agent engagements.
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82-94% end-to-end task completion on mature agents after 4-8 weeks of eval iteration; below 75% signals prompt and tool design needs rework.
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8-16 weeks for production AI agent including tool-use eval, safety scaffolding and audit trail[5].
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$2.5k-$15k per month in inference and tool spend for mid-volume agents; scales to $20k-$60k at high-volume use.
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3-15 tool calls per task on mature agents; outlier runs at 50+ calls flagged for investigation within 24 hours.
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Prompt or tool-set changes ship in 2-4 hours after eval parity check; major architecture changes 1-2 weeks.
AI agent development outlook 2026-2027
Three shifts are reshaping how autonomous AI agents move from demo to production.
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Function calling and constrained tool use reach 90%+ call success on well-defined tools. Teams that skip tool-invocation eval ship agents that loop or misfire[2].
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Planner-executor, critic-editor and hierarchical coordinator become first-class architectural patterns. Teams that invent bespoke orchestration pay 2-4x maintenance premium[11].
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Action budgets, scope constraints and rollback paths become mandatory for agents that touch production systems[8].
Our four-dimension AI agent evaluation template
Every AI agent we ship runs against the same four-dimension readiness evaluation before production.
Production post-mortem
When an agent looped 340 times on one email
A customer service agent deployed in July 2025 hit a corner case where the reply-send tool returned ambiguous success/failure status. The agent interpreted the ambiguous response as "try again" and resent the same email 340 times before the tool-call budget tripped. Caught when the customer raised a ticket about mailbox flooding.
Tool-call budget and deduplication key now mandatory on every stateful tool. Idempotency keys added to email and message-send actions. Tool-response ambiguity eliminated via explicit status codes.
Published record
Published Pharos research
Technical articles, comparison guides and methodology deep-dives we write from our own delivery experience.
- State of AI Development Costs 2026
- AI Agent Frameworks Comparison 2026
- Build vs Buy AI Agent: 2026 Decision Framework
- RAG vs Fine-Tuning: When to Use Each Approach
- How to Choose an AI Development Company
- State of Smart Contract Audits 2026
- State of Production AI Engineering 2026
- State of FinTech Compliance Cost 2026
- State of Custom Software TCO 2026
- State of AppSec 2026
- State of Tech Due Diligence 2026
- How to Choose a Blockchain Development Company
- How to Choose a FinTech Development Company
- FinTech Compliance Checklist 2026: PCI DSS, SOC 2, GDPR and Beyond
- AI in FinTech: Transforming Financial Services in 2026
- Software Development Cost Guide: What to Expect in 2026
- How to Choose a Software Development Company in 2026
- Cybersecurity Essentials for Startups and SMBs in 2026
- FinTech Trends 2026: How Top FinTech Trends are Shaping Digital Banking
Platforms We Work With
Trusted by Coinbase, Consensys, Core Scientific, MicroStrategy, Gate.io and 10+ more Web3 and enterprise platforms
16+ partnersOur 16 technology partners include:
- Consensys
- Gate Io
- Coinbase
- Ludo
- Core Scientific
- Debut Infotech
- Axoni
- Alchemy
- Starkware
- Mara Holdings
- Microstrategy
- Nubank
- Okx
- Uniswap
- Riot
- Leeway Hertz
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Consensys
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Gate Io
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Coinbase
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Ludo
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Core Scientific
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Debut Infotech
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Axoni
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Alchemy
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Starkware
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Mara Holdings
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Microstrategy
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Nubank
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Okx
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Uniswap
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Riot
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Leeway Hertz
About Founder and CTO
Founder and CTO Pharos Production
I design and build reliable software solutions – from lightweight apps to high-load distributed systems and blockchain platforms.
PhD in Artificial Intelligence, MSc in Computer Science (with honors), MSc in Electronics & Precision Mechanics.
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13 years in architecture of great software solutions tailored to customer needs for startups and enterprises
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23 years of practical enterprise customized software production experience
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Lecturer at the National Kyiv Polytechnic University
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Doctor of Philosophy in Artificial Intelligence
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Master’s degree in Computer Science, completed with excellence
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Master’s degree in Electronics and precision mechanics engineering
Choose your cooperation model
Feasibility study, prototype on your data and integration roadmap in four to eight weeks.
Full model development, API layer, cloud deployment and MLOps with monitoring.
Multi-model architecture, custom data infrastructure, compliance and hybrid or on-prem delivery.
Prices vary based on project scope, complexity, timeline and requirements. Contact us for a personalized estimate.
Or select the appropriate interaction model
Request staff augmentation
Need extra hands on your software project? Our developers can jump in at any stage – from architecture to auditing – and integrate seamlessly with your team to fill any technical gaps.
Hire dedicated experts
Whether you’re building from scratch or scaling fast, our engineers are ready to step in. You stay in control, and we handle the code.
Outsource your project
From first line to final audit, we handle the entire development process. We will deliver secure, production-ready software, while you can focus on your business.
Technologies, tools and frameworks we use
Our engineers work with 45+ ai technologies - chosen for production reliability and performance.
AI and Machine Learning
LLM Providers 8
AI Frameworks 15
Vector Databases 7
MLOps and Infrastructure 11
AI Agent Tools 4
Partnerships & Awards
Recognized on Clutch, GoodFirms and The Manifest for software engineering excellence
An approach to the development cycle
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Team Assembly
Our company starts and assembles an entire project specialists with the perfect blend of skills and experience to start the work.
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MVP
We’ll design, build and launch your MVP, ensuring it meets the core requirements of your software solution.
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Production
We’ll create a complete software solution that is custom-made to meet your exact specifications.
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Ongoing
Continuous Support
Our company will be right there with you, keeping your software solution running smoothly, fixing issues, and rolling out updates.
AI agent glossary 8
- AI Agent
- A software system that uses a language model to plan and take actions toward a goal, calling tools and APIs rather than only answering questions. Agents loop between reasoning and acting, which lets them handle multi-step tasks with limited human input.
- LLM (Large Language Model)
- A model trained on vast text that generates and understands natural language. LLMs are the reasoning core of modern AI agents, but they need grounding, tools and guardrails to be reliable in production.
- RAG (Retrieval-Augmented Generation)
- A technique that fetches relevant documents from a knowledge base and feeds them to the model so answers are grounded in current, specific data. RAG reduces hallucination and lets an agent work with private or up-to-date information.
- Tool Calling
- The mechanism that lets an agent invoke external functions, APIs or databases to act in the world. Well-defined tools with clear inputs and outputs are what turn a chatbot into an agent that can actually get work done.
- Hallucination
- When a model produces fluent output that is factually wrong or invented. It is the central reliability risk in AI systems, mitigated with retrieval, verification steps and constraining the model to trusted data and tools.
- Vector Database
- A store that holds text as numerical embeddings and retrieves items by semantic similarity rather than exact keywords. It is the retrieval layer behind most RAG systems, letting an agent find relevant context fast.
- Prompt Engineering
- Designing the instructions and context given to a model to get reliable, well-formatted results. In agents this extends to system prompts, tool descriptions and examples that shape how the model reasons and acts.
- Guardrails
- The checks and limits that keep an agent behavior safe and on-task, such as input validation, output filtering and action approval. Production agents need guardrails to prevent harmful, off-topic or runaway actions.
AI agent development FAQ
Type to filter questions and answers. Use Topic to narrow the list.
Showing all 9
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Try a different keyword, change the topic, or clear filters
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Build an agent when the task requires multi-step reasoning, tool use (databases, APIs, code execution), conversation state across turns, or routing between specialized capabilities. Use a direct LLM call (OpenAI/Anthropic SDK) for single-shot tasks: classification, summarization, structured extraction, single-question Q&A. Most “AI features” are actually direct calls. Agents are for workflows, not features.
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Single-purpose agent MVP 6-10 weeks: 2 weeks discovery and evaluation set creation, 4-6 weeks build (prompts, tools, guardrails, eval harness), 2-4 weeks production hardening (drift detection, monitoring, rollback). Multi-agent system 4-6 months. The biggest variable is the evaluation set - building a high-quality 150-200 question eval set from real production data takes time and is non-negotiable.
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Pilot agent $60,000-$120,000. Production multi-agent system $240,000-$680,000. Enterprise platform $510,000-$1,600,000. Cost drivers: number of tools the agent integrates with, evaluation set complexity, observability and audit logging, regulatory requirements, post-launch monitoring tier. The biggest hidden cost is NOT the LLM bill - it is the evaluation set, guardrails and observability you need to safely run agents in production.
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Layered controls: grounded retrieval (RAG with citation tracking), structured output schemas with validation, confidence thresholds with human handoff, evaluation set tested on every deploy, runtime guardrails that flag low-confidence answers. We instrument every response so you can audit any answer back to its source documents. Hallucinations cannot be eliminated, but they can be detected, contained and recovered from.
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LangChain or LlamaIndex for most production work - biggest ecosystems, best tool integrations. DSPy when we need structured prompt optimization. OpenAI Assistants API or Anthropic Claude tool use for simpler agent patterns. Sometimes no framework at all - a tight loop of LLM call + tool dispatch is often the cleanest production code. The choice depends on agent complexity, observability needs and team familiarity.
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Every agent ships with an evaluation set of 150-300 questions tied to business outcomes (deflection rate, citation precision, task completion, customer satisfaction). The eval set runs on every deploy and on a nightly schedule against the production model.
Drift is measured month-over-month on the same eval set with the same model - if accuracy drops more than 3 points, we investigate. Human spot-checks supplement automated evals on consequential decisions.
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For PHI (HIPAA) and PCI data: tokenization or de-identification before the LLM ever sees it; private model deployment when needed (Vertex AI private endpoints, AWS Bedrock with VPC, self-hosted Llama). Audit logging of every prompt, response and tool call. Model versioning with rollback on accuracy drift. Compliance attestations issued by accredited auditors based on the systems we deliver.
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EU data subject workflows run inside the region by default (AWS Frankfurt, GCP Belgium, Azure West Europe). Personal data is redacted or tokenized before the LLM ever sees it, with the redaction key held by the client. Every agent decision that affects a natural person is logged with the full prompt, tool calls, retrieved context and final output, so we can satisfy a GDPR right-to-explanation request in minutes rather than days. For EU AI Act high-risk use cases we classify the system upfront against Annex III, document the risk profile, run bias and fairness checks on the evaluation set and maintain a version history of prompts and models so the regulator audit trail is available from day one.
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We decline single-prompt features dressed up as agents (use a direct call), agents without an evaluation set tied to business outcomes (no way to know if the agent works), workflows that need zero-error guarantees on individual actions (medical dosing, financial settlement), real-time systems with sub-100ms latency budgets and projects with no plan for prompt maintenance or drift monitoring.
The Pharos takeaway on AI agent development
AI agents reward teams that design with tool-use reliability, scope constraints and audit trail as first-class concerns rather than assuming models behave[8]. Tool-call eval, multi-agent orchestration pattern selection and governance artifacts are the three areas that separate production AI agents from lab demos.
Book a 30-minute AI agent readiness call
Ship an agent that passes evaluation before it passes traffic
Book a 30-minute call with our AI delivery team and walk away with a scoped evaluation set, a sandbox plan and an honest yes-or-no on whether an agent is the right answer for your workflow.
What happens next?
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Contact us
Contact us today to discuss your project. We’re ready to review your request promptly and guide you on the best next steps for collaboration
Same day -
NDA
We’re committed to keeping your information confidential, so we’ll sign a Non-Disclosure Agreement
1 day -
Plan the Goals
After we chat about your goals and needs, we’ll craft a comprehensive proposal detailing the project scope, team, timeline and budget
3-5 days -
Finalize the Details
Let’s connect on Google Meet to go through the proposal and confirm all the details together!
1-2 days -
Sign the Contract
As soon as the contract is signed, our dedicated team will jump into action on your project!
Same day
Our offices
Headquarters in Las Vegas, Nevada. Engineering office in Kyiv, Ukraine.