Java developer(Fulltime)

KRG Technologies Inc. 25000 | Avenue Stanford | Suite 253 | Valencia, CA 91355  Phone no:361 - 661-8000 EXT 257 Concurrency How to deal with multiple threads understand (Executors, Callable, Futures) pros and cons of threads and how to Data Structure How to choose best collection for a given problem Deep Understanding of Hashmap and its usage Core concepts Clear understanding of dealing with Floating Point Numbers Difference between reference equals and identity equals OO Design Understanding of good software design – Immutability, Single Responsibility Principle Testing Understand Test Driven Development – Knows Junit, Mocks difference between unit/integration test JDBC - database Demonstrate good understanding of Data Access layer Pattern Demonstrate good experience in JDBC coding nice to have ORM mapping - Hibernate, JPA Java 8 (nice to have) stream api and lambda’s – Nice to have Architecture Skills Demonstrate ability to think on their feet with sample problems Understand core design patterns. (Decorator, Observer, Façade, Strategy) Be able to give use cases and explain how to Demonstrate Really good understanding of Messaging Patterns including Webservices Demonstrate understanding of "micro service" a.k.a component architecture, SOA Nice to have Distributed System problems/challenges of dealing with distributed applications across geographically separate data centers. Nice to have Experience in High Performance Environment a big plus Distributed Messaging (nice to have) Issues with trying to ensure a message was delivered from point A to point B Prior use with JMS or AMQP a plus however we use proprietary messaging framework How best to trace message flow between different locations How best to optimize throughput in a distributed messaging system Algorithmic Skills How to design stateful, event-driven algorithms Solid understanding of Algorithmic time complexity and "big-O" notation Networking Skills (nice to have) Understanding of how IP protocol works (Routing, DNS, ICMP) Understanding of TCP and UDP and experience developing TCP based client using either blocking/non-blocking socket IO tools Understand of how to debug lost or garbled connection over a highly distributed system Difference between Blocking Socket IO and Non-Blocking Socket IO Able to think on their feet and be able to handle white board problems in this area Build/OS Skills Experience using Maven 3.x and Nexus Repository Experience with TeamCity/Jenkins build server Understand Linux command line tools – bash, wc, tail, grep, pipe Basic understanding how to connect and manipulate data in an oracle dbms – DML and DDL Intangible Skills Ability to learn custom frameworks and new tools quickly Ability to selectively apply concepts and implement techniques provided by other frameworks. Ability to invent new tools and yet not re-invent the wheel Immediate Interview