Marc J Sandifer

Product Lead

Berlin, Germany

German (native)
English (native)
Python (learning)


Servant LeadershipProduct OwnershipWeb Analytics

Training & Mentoring

Data-Driven UX


Cross-functional Teams

CRO & Testing

Agile Processes


Jun. ’21 – current, Contorion GmbH, Berlin



Team Lead Product Management

• Establishing, shaping, and leading Contorion’s ‘E-Commerce Experience’ team
• Hiring, leading, coaching and empowering 3 Product Managers in charge of all customer-facing features, as well as Contorion’s product innovation efforts
• Driving Contorion’s A/B testing and personalization efforts

Nov. ’19 – May ’21, Contorion GmbH, Berlin



Senior Product Manager

In addition to the tasks and responsibilities listed under “Product Manager”:

Onboarding & Training
• Onboarding, training and supervision of a Product Management Trainee (1-year program)
• Training & Mentorship of a Junior Product Manager
• Onboarding of all new Product Managers in the areas CRO, web analysis and marketing, as well as Contorion’s systems and processes
• Shaping Contorion’s frontend, UX and testing strategy

Editorial: “Improving an Online Shop”

Mar. ’18 – Oct. ’19, Contorion GmbH, Berlin



Product Manager

Product Manager and Product Owner in charge of large-scale ecommerce development projects.
Establishing and solidifying Contorion’s CRO, data-driven UX and AB testing efforts.

Product Ownership
• Product Owner of an 8 – 12 person Scrum team
• Taking features from concept to release, including AB testing and user research
• Creating and maintaining the team’s development roadmap
• Sprint planning and monitoring in a Scrum environment
• Continuous data-driven feature design and implementation

Conversion Rate Optimization
• Establishing testing and data-driven UX culture
• Onboarding and mentoring all Product Managers in conversion rate optimization, testing, and data-driven UX
• Identifying and solving major UX blockers, significantly improving key metrics across the funnel
• Leading stakeholder CRO teams
• Analysis and tracking of all relevant KPIs
• Implementation and maintenance of web analysis tools

EDI Management & KPI Tracking
• Integrating new merchants with contorion’s EDI system
• Handling all relevant merchant communication
• Assisting other departments with KPI tracking and AB testing

Jan. ’17 – Feb. ’18, Nexon Europe GmbH, Berlin



(Lead) Product Manager

Lead Product Owner of ‘Combat Arms’, Nexon Europe’s highest grossing product.
Managing a team in charge of Product Operations.

Main Responsibilities
• Management of a product operations team
• Onboarding, training, supervision and mentorship of all team members
• Development Roadmap
• Monetization
• Event Planning
• Content Planning
• Product Sourcing and Market Research

Supervision and Coordination
• Database Administration
• Operations Engineering
• QA
• Marketing
• Customer Support
• Community Management

Combat Arms Interview: UI/UX Update

Oct. ’13 – Dec. ’16, Nexon Europe GmbH, Berlin / Luxembourg



Associate Product Manager

In charge of all tech-related and creative projects for ‘Combat Arms’ and ‘War Rock’, Nexon Europe’s highest grossing products.

Main Responsibilities
• Build Management
• QA Coordination
• Marketing Coordination
• Game Security
• Onboarding and Training

Supervision and Coordination
• Database Administration
• Operations Engineering
• QA
• Customer Support
• Community Management

Assistance / Support
• Monetization
• Content Planning
• Event Planning

Combat Arms Player Meeting 2015