Senior Python Developer Jobs in Crystal Lake, IL

Are you an experienced, passionate pioneer in technology who wants to work in a collaborative environment? As an experienced Senior Data Engineer you will have the ability to share new ideas and collaborate on projects as a consultant without the extensive demands of travel. If so, consider an opportunity with Deloitte under our Project Delivery Talent Model. Project Delivery Model (PDM) is a talent model that is tailored specifically for long-term, onsite client service delivery.
Recruiting for this role ends on 12/31/2026.
Work you'll do/Responsibilities

• Communicate regularly with Engagement Managers (Directors), project team members, and representatives from various functional and / or technical teams, including escalating any matters that require additional attention and consideration from engagement management

• Design, develop and optimize ETL/ELT pipelines using Azure Data Factory (ADF) and Databricks

• Write and tune PySpark / Spark SQL notebooks for large-scale data transformation
• Architect end-to-end data solutions across dev → UAT → prod environments using Unity Catalog
• Lead and drive design discussions with client architects and other counterparts
• Collaborate with different teams on data contracts and schema agreements
• Lead design and optimization of high-volume data pipeline.
• Define and enforce data engineering standards - naming conventions, partitioning strategies, cluster configurations, Spark tuning
• Drive performance optimization - AQE tuning, liquid clustering, broadcast joins, shuffle partition management
• Design Databricks cluster policies, autoscaling configurations, and cost optimization strategies
• Conduct root cause analysis on production incidents and implement permanent fixes
• Mentor junior and mid-level engineers through code reviews and pair programming
• Evaluate new technologies and recommend adoption (e.g., DABs, DLT, Auto Loader, Serverless Compute, event hubs)

The Team
AI & Engineering leverages cutting-edge engineering capabilities to build, deploy, and operate integrated/verticalized sector solutions in software, data, AI, network, and hybrid cloud infrastructure. These solutions are powered by engineering for business advantage, transforming mission-critical operations. We enable clients to stay ahead with the latest advancements by transforming engineering teams and modernizing technology & data platforms. Our delivery models are tailored to meet each client's unique requirements.
Required Qualifications

• Python, PySpark, Spark SQL, SQL Server

• Azure (ADF, ADLS Gen2, Key Vault, Azure Monitor)

• Databricks (Delta Lake, Unity Catalog, Workflows)
• Apache Airflow
• Git / Azure DevOps
• Deep Spark internals (DAG optimization, spill analysis, skew handling)
• Delta Lake advanced features (time travel, deletion vectors, predictive I/O)
• Unity Catalog governance (row/column security, external locations, system tables)
• IaC - Terraform, Azure ARM templates
• Bachelor's degree, preferably in Computer Science, Information Technology, Computer Engineering, or related IT discipline; or equivalent experience
• Limited immigration sponsorship may be available
• Ability to travel 10%, on average, based on the work you do and the clients and industries/sectors you serve

The wage range for this role takes into account the wide range of factors that are considered in making compensation decisions including but not limited to skill sets; experience and training; licensure and certifications; and other business and organizational needs. The disclosed range estimate has not been adjusted for the applicable geographic differential associated with the location at which the position may be filled. At Deloitte, it is not typical for an individual to be hired at or near the top of the range for their role and compensation decisions are dependent on the facts and circumstances of each case. A reasonable estimate of the current range is $95,000 to $150,000.
This position is aligned with the Project. To view the associated benefit package, please reference this document Project/Center: USBenefitsJourneyProjectandCenterTAM .
Additional Requirements
Information for applicants with a need for accommodation: https://www2.deloitte.com/us/en/pages/careers/articles/join-deloitte-assistance-for-disabled-applicants.html
Deloitte is committed to providing reasonable accommodations for people with disabilities. If you require a reasonable accommodation to participate in the recruiting process, please direct your inquiries to the Global Call Center (GCC) at USTalentCICInbox@deloitte.com.
Recruiting tips
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Benefits
At Deloitte, we know that great people make a great organization. We value our people and offer employees a broad range of benefits. Learn more about what working at Deloitte can mean for you.
Our people and culture
Our inclusive culture empowers our people to be who they are, contribute their unique perspectives, and make a difference individually and collectively. It enables us to leverage different ways of thinking, ideas, and perspectives, and bring more creativity and innovation to help solve our clients' most complex challenges. This makes Deloitte one of the most rewarding places to work.
Our purpose
Deloitte's purpose is to make an impact that matters for our people, clients, and communities. At Deloitte, purpose is synonymous with how we work every day. It defines who we are. Our purpose comes through in our work with clients that enables impact and value in their organizations, as well as through our own investments, commitments, and actions across areas that help drive positive outcomes for our communities. Learn more.
Professional development
From entry-level employees to senior leaders, we believe there's always room to learn. We offer opportunities to build new skills, take on leadership opportunities and connect and grow through mentorship. From on-the-job learning experiences to formal development programs, our professionals have a variety of opportunities to continue to grow throughout their career.
As used in this posting, "Deloitte" means Deloitte Consulting LLP, a subsidiary of Deloitte LLP. Please see https://www.deloitte.com/us/about for a detailed description of the legal structure of Deloitte LLP and its subsidiaries.
All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability or protected veteran status, or any other legally protected basis, in accordance with applicable law.
Requisition code: 355507
Job ID 355507