a Randstad company

20 Jahre Erfahrung als CTO, Principal Software Engineer, Tech Lead - Architecture, Design, Distributed Systems - Java, Dlang, JS/Web, Python

Profil
Top-Skills
Softwarearchitektur Java DevOps JavaScript PostgreSQL SystemDokumentation Python AWS Spring Linux Network Security Projektdefinition Projektmanagement/Projektleitung amazon Redshift OLAP Englisch Muttersprache Software Managementerfahrung
Verfügbar ab
08.08.2022
Noch verfügbar - Schnell sein lohnt sich: Der Experte kann bereits für Projekte vorgesehen sein.
Verfügbar zu
100%
davon vor Ort
100%
Einsatzorte

Städte
Berlin (+20km)
PLZ-Gebiete
Länder
Deutschland
Remote-Arbeit
möglich
Art des Profiles
Freiberufler / Selbstständiger
Der Experte ist als Einzelperson freiberuflich oder selbstständig tätig.

7 Monate

2022-03

heute

Created business website using AWS Lightsail and WordPress

Founder
Rolle
Founder
Projektinhalte

  • Created business website using AWS Lightsail and WordPress
  • Designed/created Funnel software project using D, Vibe.d, NanoMsg, Apache Avro, Parsing Expression Grammar, and S2Geometry
  • Established system authentication using Apache Keycloak and JWTs
  • Set up deployment infrastructure as code using AWS CDK, Route53, Elastic Container Service, Fargate, ELB, RDS, and VPC
  • Created build pipelines using AWS CodePipeline, CodeBuild, and CodeDeploy
  • Created live demo using Google Maps API via JavaScript  

Kunde
Auf Anfrage
2 Jahre 6 Monate

2019-12

2022-05

Defined/ran quarterly Objectives and Key Results (OKRs)

Chief Technology Officer Java Kafka Protocol Buffers ...
Rolle
Chief Technology Officer
Projektinhalte
  • Defined/ran quarterly Objectives and Key Results (OKRs), used to coordinate work among 9 software teams, create accurate long-term plans, and maximize efficiency

  • Defined/ran a Performance Evaluation system with transparent job responsibilities, evaluations, promotions, and pay bands

  • Defined and managed a Software Development Life Cycle (SDLC) which included design and review of software projects, which resulted in faster delivery and fewer bugs than Klar's competitors

  • Authored architecture expansion to change Klar's credit-card provider

  • Authored architecture expansion to splitting Credit/Debit operations and users

  • Wrote architecture expansion to allow Klar to establish credit worthiness in real-time

  • Wrote architecture expansion to use multiple credit products including overdraft, bullet loans, installment loans, and much more

  • Wrote architecture expansion document for card-authorization integrated Buy Now Pay Layer and credit-line based Salary Advances

  • Restored and launched component to execute inter-bank transfers

  • Built multiple micro services in Java/Spring/Postgres with Terraform/Kubernetes infrastructure for: credit card transaction processing, real-time user statistics, rule engine based loan eligibility, loan disbursement/repayment, and much more

  • Organized and executed plan to entirely replace old monolithic system with more efficient and flexible micro-service architecture

  • Wrote core libraries used to standardize communication between major system components via HTTP REST and Apache Kafka

  • Led project to siphon system events into AWS Redshfit for Business Intelligence and Data Science

  • Provided mentoring, code/design reviewing, interviewing, and conflict resolution for teams

Kenntnisse
Java Kafka Protocol Buffers Spring amazon Redshift PostgreSQL Terraform Drools Business-Rule-Engine DevOps Kubernetes
Kunde
Klar Technologies GmbH
Einsatzort
Berlin
3 Monate

2019-09

2019-11

Built technical map of Ruby-based loan system

Principal Software Engineer
Rolle
Principal Software Engineer
Projektinhalte

  • Built technical map of Ruby-based loan system in order to speed up engineering work
  • Modified loan system to include rule-engine rule match tracking to analyze their effectiveness

Kunde
JUMO
5 Monate

2019-07

2019-11

Established infrastructure systems with Kubernetes

Consultant - Principal Engineer
Rolle
Consultant - Principal Engineer
Projektinhalte
  • Designed event-driven banking architecture based on Zookeeper, Kafka and Java microservices, while taking into account over a dozen future company goals
  • Established infrastructure systems with Kubernetes
  • Established standard software library policies and set up a Maven Repository
  • Designed and built a 3rd party financial integration system converting REST interfaces into events
  • Designed and built a system to compute cashback rewards based on user activity  
Kunde
Klar
1 Jahr 4 Monate

2018-05

2019-08

Conducted root-cause analysis of large legacy monolithic systems

Tech Lead
Rolle
Tech Lead
Projektinhalte
  • Conducted root-cause analysis of large legacy monolithic systems in N26's backend nearing their scaling limits in under a week producing an actionable plan that resolved these limits in 2 weeks
  • Optimized N26's central Transaction Processing and Notification Systems leading to a 20x gain in performance by adding multithreaded/batching algorithms in a Java Spring / PostGRE environment
  • Planned and coordinated experiment-controlled releases spanning across 5 projects using Hashicorp Consul based controls
  • Designed and built a secure runtime feature-flag system using Java Spring, FF4j, Hashicorp Consul, OAuth2, and Google Admin APIs
  • Greatly increased the speed and reliability of N26 login while protecting against load spikes using a custom semaphore based multi-threaded algorithm
  • Improved security by migrating legacy central API system from older JAX-RS/Jersey technologies to Spring 5 by updating ~8K lines of code
  • Authored 4 engineering proposals around improving scalability and security in authorization, product, and mobile App usage
  • Designed and Implemented plans to break apart Monolith system into stateless cache-aggregator micro-services while preserving existing APIs  
Kunde
N26
1 Jahr 5 Monate

2017-01

2018-05

Designed, built, and managed team of 6 engineers

Lead Member of Technical Staff Engineer
Rolle
Lead Member of Technical Staff Engineer
Projektinhalte

  • Designed, built, and managed team of 6 engineers to integrate Careem into Google Maps for Mobile
  • Built "supply" system using Java Spring Boot, ZeroMQ, PEG, and AWS Elastic Beanstalk receiving 5000 updates/sec and serving 1500 R/s with ability to effortlessly scale 10x horizontally as traffic increases. The new service operates with 100x performance/scale while reducing costs by over 99%
  • Built "captain metadata" system and led a team of 4 engineers using Java Spring Data REST, Hibernate, Second Level Cache, with a HATEOAS interface capable of abstracting database access and centralizing caching in order break up a monolithic database without breaking clients. Serves over 500 R/s effortlessly with load rising as clients migrate
  • Wrote and implemented multiple proposals including adding driver bearing information for precise ETA calculations
  • Worked with Chief Architect, VP of Engineering, and Engineering Director to define and prioritize OKRs  

Kunde
Careem
2 Jahre 9 Monate

2014-02

2016-10

Designed and built portions of a the new Team Drives Share Client

Software Engineer Level 4
Rolle
Software Engineer Level 4
Projektinhalte

  • Designed and built portions of a the new Team Drives Share Client using Google Drive API
  • Open-sourced support for Android Robolectric unit tests in Bazel (to be released) and wrote a support plugin
  • Took over and improved multi-threaded Java authorization library to generalize document access capabilities in order to support Team Drives
  • Integrated Java authorization library into Google Docs/Sheets/Slides/Drawings
  • Implemented ?Organizational Unit? support to allow Google Apps for Work to set policies for groups of users
  • Added ARIA accessibility support to the Google Drive Sharing dialog  

Kunde
Google
1 Jahr 2 Monate

2012-09

2013-10

Built a course-authoring tool

Software Engineer
Rolle
Software Engineer
Projektinhalte

  • Created initial launch version of (URL on Request), as the sole developer, within 4 weeks of hire
  • Expanded Edx-based courseware to meet MongoDB?s custom demands using MySQL, Python, and Django
  • Built a course-authoring tool using CSS, HTML, JavaScript, Python, Django, and MongoDB
  • Packaged server software and established a Debian Package Repository to update production servers on Amazon EC2

Kunde
MongoDB
1 Jahr 9 Monate

2011-01

2012-09

Developed a Python web server to serve an offline-capable HTML5 web application

Software Engineer
Rolle
Software Engineer
Projektinhalte

  •  Developed a Python web server to serve an offline-capable HTML5 web application to iPad and Android devices
  • Expanded the JavaScript client to utilize HTML5 features such as LocalStorage, ApplicationCache, and History
  • Established client MVC architecture using Backbone.js, jQuery, EJS templates, SASS Stylesheets, and Google Closure compiler
  • Collaborated in design via analysis, documentation, proposals, and refactoring to reduce complexity and improve performance
  • Maintained several Java/Spring and Java/Struts web-servers, PL/SQL stored procedures, and debugged with JBoss/Jetty/Eclipse  

Kunde
Amplify
3 Jahre 6 Monate

2007-07

2010-12

Maintained configuration generation server

Software Engineer
Rolle
Software Engineer
Projektinhalte

  • Maintained configuration generation server in Perl for remote network gateway devices over VPN
  • Built a PHP5 database abstraction REST service to combine disparate PGSQL, MySQL, and MSSQL databases into XML
  • Designed with UML and implemented an object oriented, multi-threaded, XML/XSLT Python server to replace the Perl server
  • Established Debian-style APT repository web-server secured using PGP signatures to update production servers
  • Designed complex multipathed load-balanced routing tables, firewalls, shell scripts, and software for embedded devices

2005 - 2007: Developed C++ software components


Rolle: Software Engineer

Kunde: Northrop Grumman


Aufgaben:

  • Developed C++ software components for geometric data filtering, network data security, and command and control message passing
  • Wrote white paper calculating margin of error parameters for geoid models used in GPS calculations
  • Wrote proposal on server architectures computing maximum system throughput and load balancing configurations
  • Created Perl scripts to analyze large code bases for inappropriate component dependencies

3 Jahre 9 Monate

2001-10

2005-06

Computer and Electrical Engineering

Bachelor of Science (BS), Caltech
Abschluss
Bachelor of Science (BS)
Institution, Ort
Caltech
Schwerpunkt

Coursework in:

  • Computer Algorithms
  • Distributed Systems
  • Learning Systems
  • Computer Vision
  • Digital Signal Processing
  • Feedback and Control Systems
  • Networking
  • Digital Circuits
  • Analog Electronics
  • Communication Systems
  • Embedded Systems
  • Quantum Physics
  • Thermodynamics

2011 - 2014

New York Institute of Technology-Manhattan


Coursework in:

  • Database Systems
  • Java Network Programming
  • Operating System Security
  • Compilers
  • Algorithms

  • Geschäftsleitung: Leistungsbeurteilung, Ziele definieren, Konfliktlösung

  • Software-Architektur: Geschäftsprobleme vereinfachen, organisieren, und dokumentieren. Technologie auswählen und Schnittstelle für Software definieren.

  • Software-Entwurf: Algorithmus und Datenstrukturen auswählen.

  • Software-Entwicklung: Java, Dlang, Python, JavaScript, etc.

  • DevOps: Software-Bereitstellung, AWS ECS, Kubernetes, Terraform, Jenkins, AWS CodePipeline

Englisch Muttersprache
Deutsch Fortgeschritten

Deutschsprache Zertifikat B2

Top Skills
Softwarearchitektur Java DevOps JavaScript PostgreSQL SystemDokumentation Python AWS Spring Linux Network Security Projektdefinition Projektmanagement/Projektleitung amazon Redshift OLAP Englisch Muttersprache Software Managementerfahrung
Produkte / Standards / Erfahrungen / Methoden
HTML5 Cascading Style Sheets (CSS) Django DevOps Parallel Programming AWS Elastic Beanstalk Objectives and Key Results (OKRs)

Summary:

Measure twice, cut once. I am experienced in fully understanding problems ranging from vague customer ideas all the way to convoluted call-stacks of ancient legacy systems. I follow a simple procedure: understand context, make precise requirements, pick a method, build, roll-out.  

Programmiersprachen
Java
Experte
Python
Fortgeschritten
JavaScript
Fortgeschritten
Dlang
Experte
C++
Fortgeschritten
Perl C
Datenbanken
PostgreSQL
Experte
AWS Redshift
Fortgeschritten
MySQL
Fortgeschritten
Datenkommunikation
Kafka
Experte
AWS SQS
Fortgeschritten
AWS Kinesis
Fortgeschritten
REST
Experte
HTTP
Experte
Design / Entwicklung / Konstruktion
UML
Experte
Anforderungen Definieren
Experte
Algorithmus
Experte
Datastrukturen
Experte

  • Finanz / Banking

  • Beförderung / Transportation

  • IT Sicherheit

  • Bildung

  • Militär

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