Stephan Otto, Ph.D.

Thousand Oaks, California, U.S.A.

Professional History

since 03/2021 Engineering Leader at Cisco Systems, Inc., San Jose, California, U.S.A.

• Managed direct and functional teams of more than ten engineers. Delivered critical components for 5G launch of national and global wireless operators, such as UDR provisioning in converged networks and federated provisioning of multiple core networks. Created API specifications for 5G network slice orchestration and edge management.

03/2016 - 02/2021 Technical Leader at Cisco Systems, Inc., San Jose, California, U.S.A.

• Evaluated and improved service registry implementation in the Control Center platform, performed load analysis and capacity planning, developed meta-data driven configuration automation which enabled phased migration of production system to service oriented architecture with minimal cost.
• Created and maintained RESTful API specifications for the integration of HLR, HSS and SPR components into the Control Center platform, developed templates and support classes for efficient implementation of API clients, oversaw technical integration of customers in multiple geographies.
• Designed and implemented multi-HLR provisioning solution for scalable expansion of operator networks, allowing for reuse of existing components and creation of complex business rules, created dynamic configuration updates for rollout to key customers.
• Lead distributed team of five engineers which implemented a real-time traffic management solution utilizing PCRF and OCS, as well as strategic platform enhancements such as support for IPv6, NB-IoT, VoLTE and asynchronous provisioning. Established agile, test-driven development methodology and bootstrapped the creation of micro services.
• Created API specifications for wireless network provisioning and assisted operators in the implementation of provisioning gateways. Automated the process of replicating, synchronizing and auditing subscriber profiles during operator portfolio migrations. Designed and delivered synchronization layer for the migration of several millions of live subscribers to a new PCRF platform.
• Mapped RADIUS and GTP′ interfaces to 5G network functions and designed solutions for integrating provisioning, charging and reporting functions with the 5G core network. Enhanced the data model of the IoT platform to support 5G NR and network slicing in 5G SA and NSA networks.

11/2013 - 02/2016 Software Architect at Jasper Technologies, Inc., Santa Clara, California, U.S.A.

• Consolidated and extended static IP address features in IoT platform. Debugged, analyzed and resolved data definition, transaction and synchronization issues. Created database procedures, UI and API enhancements for IP address pool management.
• Improved internal diagnostic capabilities by implementing execution contexts across SOAP, REST and message queue API's. Utilized these contexts to find performance bottlenecks and consistency issues in distributed system. Reduced support cycles by correlating error logs to user requests.
• Developed reconciliation system for Control Center platform which allows unified audit of network elements and transparent correction of discrepancies. Implemented vendor specific strategies and handled complex migration scenarios. Built comprehensive integration test suite with fully parameterized test cases.
• Developed adapter framework and aggregation module supporting distributed search and pagination. Used Spring IoC, Spring MVC, Spring Security, Spring REST clients with Apache HttpComponents and Hibernate ORM.

03/2013 - 09/2013  Director of Engineering at Become, Inc., Sunnyvale, California, U.S.A.

• Lead the engineering team of the US business unit who handled more than 10 million search requests through websites and API's per day. Maintained complex infrastructure of distributed systems in Java, C++, Python, Ruby, Perl and MySQL while adding new features as needed. Improved alignment of engineering tasks with business goals and transitioned to an agile development process. Used JIRA, Bugzilla and MediaWiki for planning and documentation.
• Built “MAX” system for optimization of client side conversions by redistribution of user traffic. Session data is aggregated over traffic channels by statistics backend written in C++ and MySQL. Runtime controller plugs into ranking and retrieval component of distributed search engine written in C++. User interface integrates with Java application for account management.
• Built web based business report in Java, MySQL, JSP, HTML, CSS and JavaScript using Tomcat and jQuery with Ajax and JSON. Ported logic from legacy Java and Ruby code while generalizing interfaces and unifying code base. Increased data availability, enforced data consistency, ensured scalability and reduced maintenance cost.
• Researched product search quality by correlating user session data with automated measures of search relevancy. Built prototypes of improved ranking functions using Java, C++ and Lucene/Solr. Analyzed performance of internet marketing campaigns using MySQL and ROOT, conducted gap analysis, spearheaded effort to improve performance predictors and developed optimized workflow.

03/2011 - 02/2013  Engineering Manager at Become, Inc., Sunnyvale, California, U.S.A.

• Built and managed team of six engineers who owned production processes and transaction data. Team provided process optimization such as algorithm training and database tuning, performance monitoring using tools like Selenium and Splunk, quality assurance for builds and projects and business intelligence based on MySQL, Ruby, Perl and R.
• Created performance report for search engine marketing campaigns using Java, MySQL and JasperReports. Report was configuration driven and supported custom outlines, overviews and summaries. Report aggregation, currency conversion, result caching, source failover and data validation were handled transparently.
• Resolved stability and performance issues in production environment by optimizing algorithms and tuning configurations. Managed migration of critical applications and databases to new hardware. Adapted setup to incompatible and inaccessible components. Measured system loads and assured capacity for seasonal increases and new initiatives.

10/2006 - 02/2011  Software Engineer at Become, Inc., Sunnyvale, California, U.S.A.

• As Acting Manager for Engineering Integration, supervised technology transfer and system integration during international expansion. Conducted technical due diligence and created roadmap for migration to unified platform. Lead dedicated team and interacted with business owners and engineering groups across the global organization.
• As member of the search engine marketing team, developed C++ and Java applications as well as MySQL functions and procedures. Built components and workflow for modeling of user traffic by semantic and performance dimensions. Implemented linear and nonlinear algorithms for portfolio optimization using GLPK and OPT++. Maintained and improved rule engine for bid optimization.
• Operated the search engine marketing system for international domain, growing a portfolio of 500,000 keywords from scratch. Automated keyword selection, evaluation, deduplication and submission. Used Java, MySQL, Shell, AWK and XSLT to optimize workflow and performance.
• Researched and implemented tf-idf ranking function for product search engine in C++. Wrote library for processing of user data in C++ and MySQL using STL, MINUIT and CppUnit. Used Condor for parallelization of offline processing and Pthreads for multithreading in online application. Analyzed user data for parameter training using machine learning and statistical modeling.

01/2006 - 09/2006  Secondary School Educator at George Campbell School of Technology, Durban, South Africa

• Taught General and Physical Science.

04/2000 - 11/2004  Research Associate at the Institute for Nuclear and Particle Physics at the University of Technology, Dresden, Germany

• Optimized the performance of the electromagnetic calorimeter of the BABAR detector by developing and implementing software algorithms for the reconstruction of electromagnetic showers. Used Fortran and C++ based tools for data processing and analysis. Performed simulations using GEANT and Maple.
• Probing the Standard Model of Particle Physics, examined data samples of the BABAR experiment for rare hadronic B meson decays. Used Bayesian filtering, linear discriminant analysis and neural networks to identify decay channels. Worked with large distributed code base using C++, Rogue Wave, Objectivity, CERNLIB and ROOT.

06/2001 - 04/2002  Research Visit at the Stanford Linear Accelerator Center, California, U.S.A.

• As shift leader in the interaction region of the electron-positron storage ring, supervised detector operation and data acquisition at the BABAR experiment. As on-call expert for the light-pulser system of the electromagnetic calorimeter, performed device maintenance and failure analysis. Wrote control and diagnostics code in Tcl, Perl and EPICS.

Academic Degrees

04/28/2005 Ph.D. in Physics (Dr. rer. nat. from University of Technology, Dresden, Germany)

01/14/2000 Graduate Physicist (Diploma from University of Technology, Dresden, Germany)

Scientific Theses

• Ph.D. Thesis “Search for the Decay B⁰ → η φ at the BABAR Experiment” (Publication, PDF)
• Diploma Thesis “Investigations in Position Reconstruction of Electromagnetic Showers with the BABAR Calorimeter” (German, PDF)

Patents

• U.S. Patent 11,765,651 “Federated provisioning on multiple core networks based on unique device identifiers.”
• U.S. Patent 10,334,414 “Managing multiple mobile devices on different operator networks.”
• U.S. Patent 10,334,413 “Managing mobile devices on different operator networks.”

PGP key (fingerprint:  6D6A 0A96 2966 9835 3017 034D 218B AE84 DBE8 BA6E)