CRO Developer – Contract
London / £350 - £375 day
INFO
RATE:
£350 - £375
LOCATION
London
Contract
CRO Developer (Contract)
Analytics Agency, CRO
London - 1 day per week in office
£300-£375 per day - Outside IR35
This is an opportunity to join a high-performing experimentation team delivering impactful conversion rate optimisation projects across a diverse client base. The team is growing quickly and has already exceeded its annual targets, creating a need for additional contract support on a flexible, part-time basis. You will contribute to a steady pipeline of web experimentation initiatives while working in a fast-paced, collaborative agency environment.
The Company
They are a specialist digital consultancy focused on optimisation, analytics and search. Their work spans three core disciplines, blending experimentation with broader customer experience and performance insights. They partner closely with media and marketing teams to translate on-site behaviour into actionable CRO strategies. The environment is delivery-focused, collaborative, and designed to move quickly when the right expertise is introduced.
The Role and Deliverables
- You will take ownership of front end development for experimentation programmes, supporting business-as-usual test delivery across multiple clients.
- Build and deploy A/B tests across client websites
- Deliver a consistent output of experimentation work, including copy and image variations
- Collaborate with CRO and analytics teams to translate hypotheses into live tests
- Work across a variety of site architectures and front end environments
- Ensure quality and accuracy of tests across browsers and devices
- Support ongoing optimisation activity with reliable, scalable code
Your Skills & Experience
- Strong experience as a front end developer within an agency environment, supporting CRO or experimentation programmes
- Proven experience working with modern JavaScript frameworks such as React and Next.js
- Strong proficiency in JavaScript, HTML and CSS for building and modifying client-side experiences
- Familiarity with experimentation platforms such as AB Tasty, VWO, Optimizely, Webtrends or Convert
- Experience delivering high volumes of front end changes in a structured and efficient way
- Ability to work across different client setups and technical stacks in a fast-paced delivery environment
How to Apply
If you have agency-side front end development experience and are available for a flexible contract, apply now for immediate consideration.
CONTACT
Lloyd Dunstall
Managing Consultant
SIMILAR
JOB RESULTS
Conversion Rate Optimization (CRO) Manager
London
£50000 - £60000
+ Advanced Analytics & Marketing Insights
PermanentLondon
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Conversion Rate Optimization (CRO) Manager
London – Hybrid (2 days per month)
Competitive salary plus benefits
This is an opportunity to lead customer experience optimisation at scale, shaping digital journeys that directly impact revenue and customer satisfaction across multiple markets. You will take ownership of experimentation strategy and deliver measurable commercial outcomes in a data-led environment that values innovation and continuous improvement.
The Company
They are a well-established organisation operating in a digital-first, customer-centric industry, serving millions of customers across international markets. With a strong reputation for service excellence and a focus on continuous innovation, they invest heavily in technology, data, and customer experience. Their collaborative culture brings together teams across product, marketing, and engineering to drive meaningful change. They offer a flexible working model designed to support both performance and wellbeing.
The Role
You will lead the end-to-end customer experience optimisation strategy, owning performance across digital journeys and driving improvements through experimentation and insight.
- Own and optimise the full digital customer journey with accountability for conversion, revenue, and customer experience outcomes
- Develop and execute a data-led experimentation and CRO strategy to improve conversion, retention, and ancillary performance
- Use analytics, user research, and behavioural data to identify opportunities and prioritise impactful changes
- Partner with engineering, UX, and commercial teams to deliver A B testing and scalable optimisation initiatives
- Define and track key CX performance metrics, reporting insights and recommendations to senior stakeholders
- Champion a culture of experimentation, leveraging emerging technologies and AI to enhance performance
- Collaborate with cross-functional teams across multiple locations to deliver a unified optimisation roadmap
Your Skills and Experience
- Strong commercial experience in customer experience optimisation, CRO, or digital product environments
- Proven ability to deliver data-driven experimentation strategies that impact conversion and revenue
- Expertise in analytics and testing tools such as Google Analytics, Tableau, Optimizely, VWO, or similar
- Solid understanding of front-end implementation, tracking, and experimentation frameworks
- Knowledge of UX and personalisation principles with a focus on customer-centric design
- Experience managing multiple initiatives and stakeholders in a fast-paced environment
- Strong communication skills with the ability to translate insight into actionable strategy
What They Offer
- Competitive salary and benefits package
- Flexible, remote-first working model with limited office requirements
- Opportunity to work on high-impact projects across multiple brands and markets
- A collaborative and innovative environment with strong career progression opportunities
- Exposure to advanced experimentation, personalisation, and AI-led optimisation
How to Apply
If you are keen to drive customer experience optimisation and deliver measurable impact, please apply with your CV to learn more.

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Senior Analytics Engineer
London
£75000 - £85000
+ Data Engineering
PermanentLondon
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Senior Analytics Engineer
London
£85,000
This is an opportunity to join a high growth tech business as they scale a modern data platform and build out a dedicated Analytics Engineering capability. You will play a key role in shaping best practice, owning core data models, and enabling faster, higher quality insights across the business.
The Company
They are a London based financial technology business focused on helping customers save, invest, and plan for the future through a simple digital platform. With a strong product offering and a growing customer base, they are investing heavily in data to support continued expansion. The Data and Insights team is evolving, with a focus on modern tooling and robust data foundations. This role sits within a collaborative environment that values quality, pace, and impact.
The Role
You will work closely with analysts and stakeholders to build and maintain scalable, analysis ready datasets. This is a hands on Analytics Engineering role with a focus on data modelling and transformation rather than dashboarding.
- Design and develop robust data models using dbt and Databricks
- Build and maintain trusted data layers to support analytics and reporting
- Work closely with insight analysts to deliver high quality, reliable data assets
- Write production level SQL and Python code
- Contribute to data governance, documentation, and best practice
- Support the development of a modern medallion architecture
- Identify opportunities to improve data workflows and platform efficiency
Your Skillls and Experience
- Strong commercial experience with SQL and Python
- Proven Analytics Engineering experience within a modern data stack such as Databrickss
- Hands on experience with dbt
- Experience working in a fast paced, established data environment
- Strong understanding of data modelling, testing, and CI CD principles
- Ability to communicate effectively with both technical and non technical stakeholders
- Proactive approach with a focus on continuous improvement

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AI/ML Engineer
$70 - $80
+ Data Science & AI
ContractUSA
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Job Title
AI/ML Engineer: Multi Agent Analytics Platform
Intro Harnham
Harnham is partnering with an innovative organisation building next generation data products. We are looking for an experienced AI/ML Engineer to help deliver a production ready agent driven analytics platform.
Intro client
Our client is developing a cutting edge analytics system powered by large language models. The platform enables users to ask complex business questions in plain English and receive explainable, data backed insights in real time.
Role Details
Role: AI/ML Engineer
Location: Remote, Continental US-based
Pay: $70 to $80 per hour
Length: 12-month initial term with potential extension
Utilisation: 40 hours per week
Intro to role
This role sits at the intersection of machine learning, data engineering, and distributed systems. You will design and operate a network of AI agents that collaborate to query data, run analysis, and generate outputs such as reports and dashboards. You will own system quality end to end, ensuring results are accurate, traceable, and production ready.
Key Responsibilities
- Design multi agent workflows including planning, execution, and agent handoffs
- Build tools for data querying, validation, retrieval pipelines, and visualisation
- Develop evaluation frameworks with test datasets and automated grading systems
- Improve accuracy through guardrails, validation logic, and grounded data outputs
- Optimise performance for latency, cost, and system reliability
- Implement logging and observability for full traceability of agent behaviour
Requirements: Must have
- 5 plus years software engineering experience with 2 plus years in ML or LLM systems
- Strong Python skills and experience with LLM orchestration frameworks
- Experience with tool calling, retrieval augmented generation, and agent based patterns
- Hands on work with evaluation frameworks and observability for LLM systems
- Solid SQL and experience working with modern data warehouses
- Experience deploying and maintaining production systems
Nice to have
- Background in analytics or business intelligence workflows
- Experience with data governance and secure data handling
Outro
This is an opportunity to shape a high impact AI platform used for real business decisions. If you enjoy building reliable AI systems at scale, apply now.
We will not be engaging with third parties on this search. Please apply directly if you are a candidate interested in the role.

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Data Engineer
Manchester
£45000 - £60000
+ Data Engineering
PermanentManchester, Greater Manchester
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Data Engineer
UK Remote £45,000 to £60,000
This is an opportunity to join a growing data function building modern cloud data platforms from the ground up. You will work in a fully remote environment with real ownership across the full lifecycle, from design through to deployment, on greenfield data projects that have a direct impact on the wider business.
The Company
They are a scaling organisation investing heavily in their data capability and building a high performing engineering team. The function is led by an experienced Head of Data, with a mix of data and analytics engineers already in place. They operate a remote first model across the UK and Republic of Ireland, creating a flexible and autonomous working environment. Hiring is ongoing as the team continues to grow.
The Role
You will contribute to the development of modern data solutions in a collaborative engineering team. Key responsibilities include:
- Designing and developing scalable data pipelines for ingestion and transformation
- Writing high quality SQL for complex data modelling and analytics use cases
- Implementing dimensional models using Kimball methodologies
- Working with cloud data warehouse technologies such as Snowflake or BigQuery
- Supporting analytics use cases and collaborating with stakeholders across the business
- Contributing to data platform improvements and best practices
Your Skills and Experience
- Strong commercial experience writing complex SQL, including CTEs and window functions
- Experience working with modern cloud data warehouses such as Snowflake, BigQuery or similar
- Solid understanding of dimensional modelling and data warehousing concepts
- Exposure to data transformation tools such as DBT is beneficial
- Basic knowledge of Python, ideally in the context of orchestration tools like Airflow
- Confident communication skills and the ability to work effectively in a remote team
- A proactive approach with the ability to take ownership and solve problems independently
What They Offer
- Opportunity to work on greenfield projects with modern technologies
- Clear progression opportunities as the team continues to scale
- Autonomy and ownership in a high trust environment
How to Apply
If you are interested in this Data Engineer opportunity, please apply with your CV to find out more.

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VP AI Engineer
New York
$200000 - $220000
+ Data Science & AI
PermanentUSA
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VP AI Engineer
$220K base + bonus + RSU
New York or San Francisco
A global financial technology organisation operating at enterprise scale, combining advanced software engineering, data science, and applied AI to modernise large-scale production systems. The company invests heavily in automation, operational excellence, and AI-driven infrastructure, building mission-critical platforms used across complex, high-reliability environments.
Mission
- Design and deploy agentic AI systems to automate and optimise large-scale production environments
- Build LLM-powered solutions that diagnose issues, reason over complex systems, and take secure, auditable actions
- Develop RAG pipelines and domain knowledge systems with strong data quality, feedback loops, and governance
- Productionise LLMs: evaluation frameworks, prompt orchestration, response validation, self-correction loops
- Integrate AI agents with observability, incident management, deployment, and runtime platforms
- Implement safety, reliability, and compliance guardrails (policy enforcement, rollback strategies, circuit breakers)
- Optimise performance, cost, and latency through prompt engineering, caching, routing, batching, and streaming
Profile
- Bachelor’s degree in a quantitative or computational field (Master’s / PhD preferred)
- 7+ years of experience in applied ML, data science, or software engineering in production environments
- Strong hands-on development in Python (or C++ / Java / Go), building large-scale applications
- Practical expertise with LLMs: prompt engineering, fine-tuning/adaptation, RAG, tool-calling agents, vector search
- Experience building secure, explainable, and reliable AI systems with strong governance and auditability
- Comfortable collaborating across engineering, infrastructure, and operations teams with measurable business outcomes

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Senior ML Engineer
New York
$190000 - $210000
+ Data Science & AI
PermanentNew York
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Senior ML Engineer
NYC
Up to $200K base + bonus + equity
Company
A global, AI-driven technology company operating at the intersection of machine learning, large-scale data, and digital advertising. The business builds advanced optimization and decisioning systems used by some of the world’s largest brands to improve performance at massive scale. Environment is highly technical, product-focused, and data-heavy, with real-world impact and strong engineering culture.
Mission
- Own and improve advanced optimization and bidding algorithms used in production
- Design, develop, and ship new ML-driven features and products
- Solve non-standard ML and statistical problems
- Operate and support production ML systems, including incident analysis and impact assessment
- Partner closely with Product and Engineering to translate business needs into technical solutions
- Contribute to system design, code reviews, and architectural decisions
- Release features continuously using CI/CD and infrastructure-as-code practices
Profile
- Master’s degree (or equivalent) in Applied Mathematics, Statistics (Mandatory)
- Minimum 3+ years of professional experience building data-driven or ML systems (excluding internships)
- Hands-on exposure to production environments
- Strong communication skills and ability to work in cross-functional teams
- Experience in AdTech or large-scale optimization systems is a plus, but not required

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Senior AI Engineer
new york
$200000 - $200000
+ Data Science & AI
PermanentNew York
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Senior AI Engineer
New York (in person)
Up to 200K base + bonus
I’m working on an exclusive search for a Senior AI Engineer to join a high‑calibre investment organization that is building an internal AI and data science capability from the ground up.This is a hands‑on, senior‑level engineering role with real ownership. You’ll sit close to decision‑makers and design production AI systems that directly influence how investments are sourced, evaluated, and monitored.
The opportunity
- Act as the technical lead for advanced AI and LLM‑driven systems used across investment workflows
- Own architecture and complex builds, including agentic workflows, RAG systems, and evaluation frameworks
- Lead development of high‑impact projects spanning research, diligence, portfolio monitoring, and knowledge management
- Set technical direction, review code, and mentor engineers while remaining fully hands‑on
- Partner closely with non‑technical stakeholders to translate AI capabilities into intuitive, high‑value tools
- Evaluate vendors, platforms, and infrastructure with clear build vs buy recommendations
Background they’re looking for
- 5+ years of software engineering experience, including 2+ years building production AI/ML or LLM‑based systems
- Strong Python fundamentals and experience with cloud infrastructure (AWS) and CI/CD
- Deep understanding of modern LLM patterns: embeddings, vector databases, prompt engineering, RAG, agentic systems, and evaluation
- Experience delivering end‑to‑end AI products, not just prototypes
- Comfortable leading technically in a small, high‑impact team
- Clear communicator who can work effectively with non‑technical partners
- Financial services experience is a plus, but curiosity about investment decision‑making is essential
Why this is compelling
- Rare chance to build AI platforms from scratch inside a decision‑driven environment
- Significant technical ownership and visibility at senior levels
- Small team with high expectations and real influence
- Competitive compensation and strong long‑term upside

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AI/ML Engineer – Multi-Agent Data Analytics Platform
New York
$70 - $80
+ Data Engineering
ContractNew York
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AI/ML Engineer – Multi-Agent Data Analytics Platform
Harnham, the leading recruitment specialist in Data and AI, is currently partnering with a leading DTC Media Streaming firm that operates across the US.
- Role – ML/AI Engineer
- Location – Remote
- Pay – $70 – 80 per hour W2 ONLY
- Length – 6 months
- Utilization – 40 hours per week
- Benefits – 401K Match, Medical, Dentistry
As an AI/ML Engineer, you will be building an agentic analytics platform: a system of cooperating LLM-powered agents that query data sources, run analysis, generate visualizations, and turn natural-language questions into trustworthy, explainable answers. You will design, build, and operate both the agents and the infrastructure that ensures production reliability, working at the intersection of applied ML, distributed systems, and data analytics.
Key Responsibilities:
- Design and implement multi-agent workflows (planner/executor patterns, tool-calling, routing, memory, and handoff between specialized agents)
- Build and maintain tools agents rely on, including SQL generation and validation, data connectors, retrieval pipelines, visualization, and result verification
- Develop evaluation frameworks such as offline test suites, golden datasets, LLM-as-judge grading, and regression tracking
- Optimize system performance across latency, cost, throughput, and failure handling
- Implement observability through tracing, logging, and monitoring for debuggability and auditability
- Collaborate with cross-functional teams to define correctness in analytics queries and encode it into the system
- Stay current with LLM and agent tooling and make pragmatic build vs. buy decisions
Requirements:
- 5+ years of software engineering experience, including 2+ years building ML/AI or LLM-powered production systems
- Strong Python skills and experience with modern LLM frameworks (e.g., LangGraph or OpenAI Agent SDK)
- Experience with tool/function calling, RAG, prompt design, and agent-based architectures
- Hands-on experience with evaluation frameworks and observability tools for LLM systems
- Experience with vector databases and retrieval optimization
- Experience optimizing LLM systems for cost and latency (e.g., caching, batching, model routing)
- Strong data fundamentals including SQL and experience with data warehouses/lakehouses
- Strong communication skills and ability to translate ambiguous business questions into technical solutions
This is an excellent opportunity for an ML/AI Engineer to work on cutting-edge agentic systems, shaping how users interact with data through intelligent, explainable analytics platforms. So if you are interested, please apply below or contact Ciarán at Harnham

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Senior Consultancy Manager
London
£100000 - £120000
+ Risk Analytics
PermanentLondon
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Senior Consulting Manager
Salary
£100,000-£120,000 + bonus
Location + work pattern
London or Leeds (Hybrid – 2 days per week in office/client site as required)
THE COMPANY
This organisation is a well-established provider of data, analytics and decisioning solutions to major financial services, fintech and payments businesses. As part of a strategic expansion, they are investing in a high-impact consulting function designed to help clients turn data into tangible commercial outcomes across the customer lifecycle.
THE ROLE
You will lead end-to-end analytics consulting engagements, acting as a trusted advisor to senior stakeholders while helping to build and scale a growing consulting capability. This is a highly visible role with clear progression into leadership.
Specifically, you can expect to be involved in:
- Leading delivery of analytics-led consulting projects from problem definition to actionable recommendations
- Owning senior client relationships across banking, fintech and payments organisations
- Translating complex analytical outputs into clear, commercially focused insights
- Supporting business development through proposals, pitches and shaping new opportunities
- Collaborating with data science and analytics teams to deliver scalable, high-quality solutions
YOUR SKILLS AND EXPERIENCE
- Proven experience in analytics or data-led consulting within financial services, fintech or payments
- Experience within a credit risk environoment, working on customer acquisition or ECM.
- Strong client-facing skills with the ability to manage senior stakeholders and lead project
- Ability to communicate complex ideas clearly to both technical and non-technical audiences
- Understanding of lending products (e.g. credit cards, loans, mortgages) and customer lifecycle analytics
- Familiarity with analytical tools such as SQL, Python or visualisation platforms
THE BENEFITS
- Performance-related bonus
- Competitive ension and healthcare package
- Generous annual leave allowance
- Flexible and hybrid working model
- Ongoing learning and development opportunities
THE PROCESS
- Initial interview
- Case study / presentation stage
- Final senior stakeholder interview
HOW TO APPLY
Please register your interest via the apply link on this page.

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Director, Data Center Site Operations (Campus Lead)
Dallas
$175000 - $275000
+ Data Engineering
PermanentDallas, Texas
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Director of Data Center Site Operations (Campus Lead)
Location: Dallas, TX – Remote
Full-Time | Onsite
Salary: up to $275,000 + equity + bonus
Overview
We are seeking a Director of Data Center Site Operations (Campus Lead) to oversee all aspects of operations for a large-scale data center campus. This senior leadership role will be responsible for site-wide performance, uptime, and operational strategy, while leading multiple teams across engineering, facilities, and operations.
Responsibilities
- Lead end-to-end operations for a multi-building data center campus
- Ensure 99.999% uptime and world-class reliability performance
- Oversee site leadership team (managers across operations, critical facilities, and engineering)
- Drive incident management, root cause analysis (RCA), and continuous improvement programs
- Own site-level operating metrics, SLAs, and reporting
- Manage relationships with key vendors, utility providers, and partner organizations
- Partner with global operations, construction, and engineering teams on capacity expansion and upgrades
- Establish and enforce operational standards, safety protocols, and compliance frameworks
- Lead workforce planning, hiring, and leadership development initiatives
Required Skills
- 10-15+ years in data center, critical facilities, or mission-critical operations
- Proven experience leading large-scale sites or multi-site environments
- Deep expertise in electrical and mechanical infrastructure (UPS, generators, switchgear, HVAC/chilled water systems)
- Strong track record of operational excellence, uptime management, and SLA ownership
- Experience managing layered leadership teams (managers + individual contributors)
- Familiarity with capacity planning, infrastructure lifecycle management, and expansion projects
- Strong understanding of regulatory, safety, and compliance standards (OSHA, NFPA, NEC)
- Executive-level communication and stakeholder management skills
Preferred Qualifications
- Experience in hyperscale, cloud, or large colocation environments
- Background in Lean, Six Sigma, or operational excellence methodologies
- Bachelor’s degree in Engineering, Facilities Management, or related field (or equivalent experience)
Requirements
- Must be authorized to work in the U.S. (no sponsorship available)

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Head of Data Center Capacity & Strategy
New York
$300000 - $400000
+ Data Engineering
PermanentNew York
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Head of Data Center Capacity & Strategy
Location: New York, NY / Remote (U.S.)
Full-Time
Salary: up to $400,000 + equity
Overview
We are seeking a Head of Data Center Capacity & Strategy to drive long-term infrastructure planning and growth strategy.
Responsibilities
- Develop capacity forecasting and demand models
- Align infrastructure growth with business and cloud demand
- Lead strategic planning for global data center expansion
- Partner with finance, engineering, and operations
- Evaluate market opportunities and site selection
Required Skills
- 8-12+ years in capacity planning, infrastructure strategy, or cloud ops
- Strong analytical skills and data-driven decision making
- Experience with hyperscale or cloud infrastructure growth
- Knowledge of regional power, land, and connectivity considerations
- Executive-level communication and stakeholder management
Requirements
- U.S. work authorization required (no sponsorship available)

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Director, Data Center Operations (Hyperscale)
Phoenix
$175000 - $300000
+ Data Engineering
PermanentPhoenix, Arizona
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Director, Data Center Operations (Hyperscale)
Location: Remote within the US
Full-Time | Salary: Up to $300,000
Overview
We are seeking a Director of Data Center Operations to lead multi-site operations across a growing hyperscale footprint. This role will drive uptime, operational excellence, and team leadership across critical environments.
Responsibilities
- Lead end-to-end operations across multiple data center campuses
- Ensure 99.999% uptime and SLA adherence
- Build and lead high-performing teams (managers + engineers)
- Oversee incident management, RCA, and continuous improvement
- Manage vendors and third-party service providers
- Partner with engineering, construction, and capacity planning teams
Required Skills
- 10+ years in data center or critical facilities operations
- Strong expertise in electrical/mechanical infrastructure (UPS, generators, chillers)
- Experience with Tier III/IV environments
- Proven leadership across multi-site operations
- Deep knowledge of SLA management and reliability metrics
Requirements
- Must be authorized to work in the U.S. (no sponsorship available)

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