The people behind
the outcomes.

John Esterby is the CEO of Systems Integration Specialists, where he leads company strategy, client partnerships, and technology-driven transformation for retail, warehouse, and supply chain organizations. With a background in Merchandise Management Systems and more than 30 years of experience in enterprise technology, John brings a practical understanding of how systems, operations, and execution must align to deliver measurable business value.

John has spent his career helping organizations solve complex technology challenges across connected operational environments. His experience spans WMS, ERP, order management, legacy systems, automation, and modern integration architectures, giving him a balanced perspective between business needs and technical execution.

His leadership philosophy is grounded in partnership, accountability, and execution—helping organizations move from strategy to practical results. Under his leadership, SIS is focused on trusted execution, long-term client relationships, and practical solutions that help customers improve performance and scale with confidence.

Phil Williams is the CFO of Systems Integration Specialists, where he oversees budgeting, cash management, financial reporting, and the financial discipline that supports SIS's continued growth. With more than 30 years of experience across supply chain, ERP, and financial software environments, Phil brings a practical understanding of how financial systems, operational processes, and enterprise technology must work together to support scalable business performance.

Phil has led and supported implementations for mid-sized and large organizations, with experience spanning requirements gathering, ERP conversions, data reconciliation, user acceptance testing, SQL data extraction, and production support. His work has helped clients improve operational efficiency, increase financial visibility, strengthen systems connectivity, reduce costs, and accelerate financial closing cycles.

He has deep expertise in IBM i and custom ERP implementation and conversion efforts, with particular focus in accounts payable, three-way matching, general ledger, stock ledger, freight and duty, and multi-currency environments. Known for his detail-oriented and practical approach, Phil helps bridge the gap between finance, operations, and technology—ensuring that financial systems are accurate, connected, and built to support the needs of complex retail and supply chain organizations.

Henry Belcher is a senior supply chain and distribution executive with more than 30 years of leadership and consulting experience across manufacturing, retail, direct-to-consumer, aerospace, and life sciences. He has advised Fortune 500 organizations on complex distribution challenges and has led Industry 4.0 and automation initiatives at Accenture, KPMG, Deloitte, and St. Onge.

Henry is recognized for his ability to evaluate large-scale distribution and fulfillment operations and translate strategic objectives into practical, technology-enabled solutions. His expertise spans end-to-end distribution operations, including warehouse management and execution systems (WMS, WES, WCS), network strategy, and advanced material handling and automation technologies. He has guided clients through the selection and implementation of solutions such as AS/RS, goods-to-person systems, robotics, sortation, shuttle systems, and automated packaging.

His consulting experience includes engagements with leading global organizations including Nike, Amazon, Kroger, Home Depot, CVS, Johnson & Johnson, Pfizer, AbbVie, Boeing, and Cardinal Health, supporting initiatives ranging from greenfield distribution center design to post-merger network redesign and large-scale automation deployments.

In operating leadership roles, Henry has led high-volume fulfillment and DC operations for major brands including Home Shopping Network, Victoria's Secret, The Walt Disney Company, Hanover Direct, QVC, and Avon. His responsibilities have included multi-site operations leadership, facility design and startup, inventory control, and large workforce management in environments exceeding one million square feet.

Henry brings a pragmatic, results-driven approach to supply chain transformation, combining strategic insight with deep operational and technology expertise.

Corey Flewelling brings a rare combination of operational leadership and technical delivery experience across warehouse and distribution environments. He began his career with eight years in front-line supervision and operations management before moving into a 25-year career focused on technical planning, development, configuration, and implementation.

His background gives him a practical understanding of how distribution operations work on the floor and how technology must be designed to support real-world operational requirements. Corey has supported seven greenfield distribution center launches, along with more than 20 new WMS launches, upgrades, and modernization efforts for existing operations.

Corey's experience spans 3PL, retail, wholesale, pharmaceutical, and manufacturing environments. His ability to bridge the gap between operational needs and technical solutions allows him to help organizations improve execution, system adoption, and overall warehouse performance.

He is certified in Manhattan PKMS, WMOS, MAWM, SCI, and DFIO. His additional technical and integration experience includes Labor Management, TMS, SQL, MIF, TIBCO, API/Postman, ASRS, and a variety of ERP platforms.

Venkat Marripally brings more than 25 years of experience in enterprise systems design, development, testing, technical management, and solution leadership. He has deep expertise across supply chain, retail, pharmaceutical, WMS, EDI, eCommerce, merchandising, POS, and financial systems, with particular strength in complex multi-DC and multi-channel distribution environments.

Venkat has led and managed multiple successful implementations and upgrades involving Manhattan Associates MAWM, PkMS/WMi, WMOS, JDA MMS, and Island Pacific for small, mid-sized, and large retail organizations. His work spans the full project lifecycle, from solution design and technical architecture through integration, testing, deployment, compliance, and production support. He is also well versed in SOX, ISO, and PCI standards and brings experience as a Scaled Agile Lead.

As a Principal Solutions Architect, Venkat has extensive experience integrating warehouse automation, material handling equipment, and robotics with WMS platforms. He has worked closely with leading automation and robotics providers including Dematic, Intelligrated, Honeywell, Locus Robotics, 6 River Systems, JBT, Swisslog, and PSI Engineering to connect automated fulfillment technologies with core warehouse execution processes. His expertise includes designing and supporting integrations between WMS, conveyor systems, robotics, picking technologies, sortation, and other automated warehouse solutions.

Known for combining deep technical knowledge with practical execution, Venkat helps clients modernize warehouse operations, improve system connectivity, and deliver scalable technology solutions that support accuracy, efficiency, and long-term operational performance.

Leor Gillerman brings more than 25 years of IT experience, combining deep technical expertise with real-world supply chain execution in high-volume, mission-critical environments. He has extensive experience leading large-scale WMS implementations, including Manhattan Active WMS deployments across retail, healthcare, and national distribution networks.

Leor has served in key architecture, integration, and execution roles, including leading integration efforts for the first Manhattan Active WMS deployment and supporting enterprise rollouts across 13 distribution centers. His expertise spans Manhattan WMS, middleware and API integrations, data conversion, UAT, go-live support, and post-launch stabilization.

In addition to his WMS and supply chain background, Leor brings more than 20 years of database, reporting, infrastructure, and systems management experience across Oracle, SQL Server, MySQL, Linux, Azure, Power BI, SSRS, and Cognos. He has led technical teams, built scalable implementation standards, improved system performance, and helped bridge the gap between IT and operations.

Known for translating complex business requirements into practical technical solutions, Leor is a trusted partner during large-scale transformations, go-lives, and continuous improvement initiatives.

Chirag Dua is an Integration Architect with more than 25 years of experience designing, building, and modernizing enterprise applications and integration platforms for clients across retail, pharmaceutical, banking, and supply chain environments. He specializes in developing scalable integration architectures that connect complex business systems, automate critical processes, and enable reliable data flow across the enterprise.

Over the past decade, Chirag has focused on complex middleware and cloud integration solutions that support product, customer, order, inventory, and fulfillment lifecycles. His experience includes API design, event-driven orchestration, middleware modernization, performance tuning, production hardening, and long-running migrations from legacy platforms to cloud-native architectures. He is particularly skilled at helping organizations modernize core technology environments without disrupting day-to-day operations.

Chirag brings deep experience integrating Manhattan Active Omni, Manhattan Warehouse Management Systems, MuleSoft CloudHub, and other enterprise platforms to support real-time visibility and connected supply chain execution. His work helps bridge order management, warehouse operations, and fulfillment processes, giving clients cleaner data, faster execution, and a more resilient technology foundation.

Known for navigating high-stakes technical challenges with a calm, pragmatic approach, Chirag combines deep architectural expertise with a strong focus on business outcomes—helping clients build integration solutions that are reliable, scalable, and aligned with long-term operational growth.

Lauren Doran is a seasoned digital delivery and transformation leader with more than a decade of experience guiding complex technology initiatives from strategy through execution. As a SAFe Agilist-certified professional, she has built a reputation for aligning business objectives with scalable technology solutions, helping organizations modernize operations, improve delivery performance, and drive measurable results.

Lauren's leadership style combines strategic thinking with a hands-on, results-oriented approach. She is passionate about creating high-performing teams, improving operational efficiency, and delivering technology solutions that generate lasting business value.

Her expertise spans Agile program management, enterprise systems implementation, stakeholder engagement, and process optimization. She is particularly skilled at translating business needs into actionable roadmaps and fostering collaboration among technical and non-technical teams.

Jake is a digital delivery and program management leader with more than a decade of experience guiding complex technology initiatives from strategy through execution in the retail and e-commerce space. Holding multiple Agile certifications, he has built a reputation for aligning business objectives with scalable technology solutions, helping organizations modernize digital operations, improve delivery performance, and drive measurable results.

Jake's career spans a mix of enterprise system implementations, large-scale Agile transformations, vendor and systems integrator program leadership, and PMO and portfolio management. This breadth gives him a balanced perspective across the full delivery lifecycle—from shaping roadmaps and governance models to leading hands-on execution across distributed teams.

His expertise is concentrated in modern e-commerce platforms, with deep experience leading initiatives on commercetools, and other leading composable technologies. He has guided clients through platform selection, replatforming efforts, headless and composable commerce architectures, and the operational changes required to support modern digital retail. His work consistently bridges merchandising, marketing, operations, and engineering teams to deliver connected customer experiences.

Jake's leadership style combines strategic thinking with a hands-on, results-oriented approach. He is skilled at translating business needs into actionable roadmaps, building high-performing teams, and fostering collaboration among technical and non-technical stakeholders. He is particularly effective in environments where competing priorities, tight timelines, and complex vendor ecosystems require steady program leadership.

Known for execution and accountability, Jake helps clients deliver technology programs that generate lasting business value.

Sam Raeburn brings 14 years of technical sales experience across staffing, consulting, software, and services. He has supported Fortune 100 companies, mid-sized organizations, and start-ups across a wide range of industries, including banking and finance, retail, government, utilities, manufacturing, and technology.

Sam's strengths include understanding client pain points, tailoring solutions to address business needs, and expanding relationships across organizations to increase account penetration and market share. He also brings strong new business development experience, having owned the full sales cycle from initial outreach through successful MSA execution many times throughout his career.

Known for building strong, long-term client relationships, Sam takes pride in earning trust through consistent execution, reliable support, and a practical understanding of how to align client needs with the right solutions.