cgpSoftware

http://www.indiangeek.net/programmer-competency-matrix/

This is a great link, and a good way to identify weak spots in your programming repertoire.

Heck, I copied it so I could update it into my own form. (Fair use?)

Computer Science

 
2n (Level 0)
n2 (Level 1)
n (Level 2)
log(n) (Level 3)
Comments

data structures
Doesn’t know the difference between Array and LinkedList
Able to explain and use Arrays, LinkedLists, Dictionaries etc in practical programming tasks
Knows space and time tradeoffs of the basic data structures, Arrays vs LinkedLists, Able to explain how hashtables can be implemented and can handle collisions, Priority queues and ways to implement them etc.
Knowledge of advanced data structures like B-trees, binomial and fibonacci heaps, AVL/Red Black trees, Splay Trees, Skip Lists, tries etc.

algorithms
Unable to find the average of numbers in an array (It’s hard to believe but I’ve interviewed such candidates)
Basic sorting, searching and data structure traversal and retrieval algorithms
Tree, Graph, simple greedy and divide and conquer algorithms, is able to understand the relevance of the levels of this matrix.
Able to recognize and code dynamic programming solutions, good knowledge of graph algorithms, good knowledge of numerical computation algorithms, able to identify NP problems etc.
Working with someone who has a good topcoder ranking would be an unbelievable piece of luck!

systems programming
Doesn’t know what a compiler, linker or interpreter is
Basic understanding of compilers, linker and interpreters. Understands what assembly code is and how things work at the hardware level. Some knowledge of virtual memory and paging.
Understands kernel mode vs. user mode, multi-threading, synchronization primitives and how they’re implemented, able to read assembly code. Understands how networks work, understanding of network protocols and socket level programming.
Understands the entire programming stack, hardware (CPU + Memory + Cache + Interrupts + microcode), binary code, assembly, static and dynamic linking, compilation, interpretation, JIT compilation, garbage collection, heap, stack, memory addressing…

Software Engineering

 
2n (Level 0)
n2 (Level 1)
n (Level 2)
log(n) (Level 3)
Comments

source code version control
Folder backups by date
VSS and beginning CVS/SVN user
Proficient in using CVS and SVN features. Knows how to branch and merge, use patches setup repository properties etc.
Knowledge of distributed VCS systems. Has tried out Bzr/Mercurial/Darcs/Git

build automation
Only knows how to build from IDE
Knows how to build the system from the command line
Can setup a script to build the basic system
Can setup a script to build the system and also documentation, installers, generate release notes and tag the code in source control

automated testing
Thinks that all testing is the job of the tester
Has written automated unit tests and comes up with good unit test cases for the code that is being written
Has written code in TDD manner
Understands and is able to setup automated functional, load/performance and UI tests

Programming

 
2n (Level 0)
n2 (Level 1)
n (Level 2)
log(n) (Level 3)
Comments

problem decomposition
Only straight line code with copy paste for reuse
Able to break up problem into multiple functions
Able to come up with reusable functions/objects that solve the overall problem
Use of appropriate data structures and algorithms and comes up with generic/object-oriented code that encapsulate aspects of the problem that are subject to change.

systems decomposition
Not able to think above the level of a single file/class
Able to break up problem space and design solution as long as it is within the same platform/technology
Able to design systems that span multiple technologies/platforms.
Able to visualize and design complex systems with multiple product lines and integrations with external systems. Also should be able to design operations support systems like monitoring, reporting, fail overs etc.

communication
Cannot express thoughts/ideas to peers. Poor spelling and grammar.
Peers can understand what is being said. Good spelling and grammar.
Is able to effectively communicate with peers
Able to understand and communicate thoughts/design/ideas/specs in a unambiguous manner and adjusts communication as per the context
This is an often under rated but very critical criteria for judging a programmer. With the increase in outsourcing of programming tasks to places where English is not the native tongue this issue has become more prominent. I know of several projects that failed because the programmers could not understand what the intent of the communication was.

code organization within a file
no evidence of organization within a file
Methods are grouped logically or by accessibility
Code is grouped into regions and well commented with references to other source files
File has license header, summary, well commented, consistent white space usage. The file should look beautiful.

 
2n (Level 0)
n2 (Level 1)
n (Level 2)
log(n) (Level 3)
Comments

code organization across files
No thought given to organizing code across files
Related files are grouped into a folder
Each physical file has a unique purpose, for e.g. one class definition, one feature implementation etc.
Code organization at a physical level closely matches design and looking at file names and folder distribution provides insights into design

source tree organization
Everything in one folder
Basic separation of code into logical folders.
No circular dependencies, binaries, libs, docs, builds, third-party code all organized into appropriate folders
Physical layout of source tree matches logical hierarchy and organization. The directory names and organization provide insights into the design of the system.
The difference between this and the previous item is in the scale of organization, source tree organization relates to the entire set of artifacts that define the system.

code readability
Mono-syllable names
Good names for files, variables classes, methods etc.
No long functions, comments explaining unusual code, bug fixes, code assumptions
Code assumptions are verified using asserts, code flows naturally - no deep nesting of conditionals or methods

defensive coding
Doesn’t understand the concept
Checks all arguments and asserts critical assumptions in code
Makes sure to check return values and check for exceptions around code that can fail.
Has his own library to help with defensive coding, writes unit tests that simulate faults

 
2n (Level 0)
n2 (Level 1)
n (Level 2)
log(n) (Level 3)
Comments

error handling
Only codes the happy case
Basic error handling around code that can throw exceptions/generate errors
Ensures that error/exceptions leave program in good state, resources, connections and memory is all cleaned up properly
Codes to detect possible exception before, maintain consistent exception handling strategy in all layers of code, come up with guidelines on exception handling for entire system.

IDE
Mostly uses IDE for text editing
Knows their way around the interface, able to effectively use the IDE using menus.
Knows keyboard shortcuts for most used operations.
Has written custom macros

API
Needs to look up the documentation frequently
Has the most frequently used APIs in memory
Vast and In-depth knowledge of the API
Has written libraries that sit on top of the API to simplify frequently used tasks and to fill in gaps in the API
E.g. of API can be Java library, .net framework or the custom API for the application

frameworks
Has not used any framework outside of the core platform
Has heard about but not used the popular frameworks available for the platform.
Has used more than one framework in a professional capacity and is well-versed with the idioms of the frameworks.
Author of framework

 
2n (Level 0)
n2 (Level 1)
n (Level 2)
log(n) (Level 3)
Comments

requirements
Takes the given requirements and codes to spec
Come up with questions regarding missed cases in the spec
Understand complete picture and come up with entire areas that need to be speced
Able to suggest better alternatives and flows to given requirements based on experience

scripting
No knowledge of scripting tools
Batch files/shell scripts
Perl/Python/Ruby/VBScript/Powershell
Has written and published reusable code

database
Thinks that Excel is a database
Knows basic database concepts, normalization, ACID, transactions and can write simple selects
Able to design good and normalized database schemas keeping in mind the queries that’ll have to be run, proficient in use of views, stored procedures, triggers and user defined types. Knows difference between clustered and non-clustered indexes. Proficient in use of ORM tools.
Can do basic database administration, performance optimization, index optimization, write advanced select queries, able to replace cursor usage with relational sql, understands how data is stored internally, understands how indexes are stored internally, understands how databases can be mirrored, replicated etc. Understands how the two phase commit works.

Experience

 
2n (Level 0)
n2 (Level 1)
n (Level 2)
log(n) (Level 3)
Comments

languages with professional experience
Imperative or Object Oriented
Imperative, Object-Oriented and declarative (SQL), added bonus if they understand static vs dynamic typing, weak vs strong typing and static inferred types
Functional, added bonus if they understand lazy evaluation, currying, continuations
Concurrent (Erlang, Oz) and Logic (Prolog)

platforms with professional experience
1
2-3
4-5
6+

years of professional experience
1
2-5
6-9
10+

domain knowledge
No knowledge of the domain
Has worked on at least one product in the domain.
Has worked on multiple products in the same domain.
Domain expert. Has designed and implemented several products/solutions in the domain. Well versed with standard terms, protocols used in the domain.

Knowledge

 
2n (Level 0)
n2 (Level 1)
n (Level 2)
log(n) (Level 3)
Comments

tool knowledge
Limited to primary IDE (VS.Net, Eclipse etc.)
Knows about some alternatives to popular and standard tools.
Good knowledge of editors, debuggers, IDEs, open source alternatives etc. etc. For e.g. someone who knows most of the tools from Scott Hanselman’s power tools list. Has used ORM tools.
Has actually written tools and scripts, added bonus if they’ve been published.

languages exposed to
Imperative or Object Oriented
Imperative, Object-Oriented and declarative (SQL), added bonus if they understand static vs dynamic typing, weak vs strong typing and static inferred types
Functional, added bonus if they understand lazy evaluation, currying, continuations
Concurrent (Erlang, Oz) and Logic (Prolog)

codebase knowledge
Has never looked at the codebase
Basic knowledge of the code layout and how to build the system
Good working knowledge of code base, has implemented several bug fixes and maybe some small features.
Has implemented multiple big features in the codebase and can easily visualize the changes required for most features or bug fixes.

knowledge of upcoming technologies
Has not heard of the upcoming technologies
Has heard of upcoming technologies in the field
Has downloaded the alpha preview/CTP/beta and read some articles/manuals
Has played with the previews and has actually built something with it and as a bonus shared that with everyone else

 
2n (Level 0)
n2 (Level 1)
n (Level 2)
log(n) (Level 3)
Comments

platform internals
Zero knowledge of platform internals
Has basic knowledge of how the platform works internally
Deep knowledge of platform internals and can visualize how the platform takes the program and converts it into executable code.
Has written tools to enhance or provide information on platform internals. For e.g. disassemblers, decompilers, debuggers etc.

books
Unleashed series, 21 days series, 24 hour series, dummies series…
Code Complete, Don’t Make me Think, Mastering Regular Expressions
Design Patterns, Peopleware, Programming Pearls, Algorithm Design Manual, Pragmatic Programmer, Mythical Man month
Structure and Interpretation of Computer Programs, Concepts Techniques, Models of Computer Programming, Art of Computer Programming, Database systems , by C. J Date, Thinking Forth, Little Schemer

blogs
Has heard of them but never got the time.
Reads tech/programming/software engineering blogs and listens to podcasts regularly.
Maintains a link blog with some collection of useful articles and tools that he/she has collected
Maintains a blog in which personal insights and thoughts on programming are shared

http://samizdat.mines.edu/howto/HowToBeAProgrammer.html

At first I thought this was pretty much a non-event, but the more I thought about it, the more I realized, hey, this could be pretty neat.

Amazon Exposes Public Data

Yeah, this information is out there, but Amazon has gone through the trouble of making it easier to access? That's nice. Hrm... Sounds like a trend.

Just a host of links on accessibility and javascript/ajax, with a bit of commentary...

• http://www.webaim.org/techniques/ajax/
• http://ejohn.org/blog/ajax-accessibility/

... Actually, the search works pretty good. I was trying screen readers, but that's not really the topic I'm researching...

References

• http://mediumexposure.com/node/25

There's a lot of ways this is referred to in the java world but they all essentially mean the above. The method described at dzone is good, but it really isn't runtime unless you provide a method for loading a class (which was probably beyond scope)

After really reading through what I could find on the web though, the consensus seems to be that reloading code is quirky and unpredictable. I don't like the idea of needing a custom loader either, it's all a bit overbearing when you compare it to something like scripting, so I'm using the scripting built into Java 6.

References

Often, there are times on a server you may want to install multiple applications, but you may want to update one of the applications without bringing down the others, so you need to run multiple instances. Not surprisingly, you can do this without having multiple instances of the binaries lying around. This can make it potentially "easier" (to update your tomcat, assuming there aren't any hangups with regards to dependencies/oddities on a version of tomcat.

Setting up multiple tomcats on a single server is pretty straightforward:

First, the base installation of tomcat should only need the following:

+tomcat (home)
|__bin
|__lib - contains server libraries, can be used for shared libraries


Everything else is a customizable piece of tomcat:

+tomcat (base_dir)
|___work - the deployed version of your application
|___temp - for whatever tomcat needs to do on the fly
|__ webapp - your web applications
|___log - the logs for your server
|___conf - configs for the server.

* - not all tomcats seem to have this folder

If you've created the above folder structure somewhere outside of the original tomcat installation, you are pretty much ready to go. Just set a CATALINA_BASE environment variable and you're ready to roll.

Catalina.out troubles
Catalina.out is the catch-all files for console output. (All those who have used System.out.println are familiar with it)

One thing I find a bit annoying about the catalina startup script is that it does not provide a way to change the default name of this file. There's a dozen environment variables, but none to change the console output filename. You can do this yourself by simply searching for catalina.out in your catalina.sh script and replcing it with an environment variable choice.

The other gotcha about this file is that there are no restrictions on it's output length, and it can eat your disk space up complete if you're not careful. A couple of ways to deal with it:

• Setup a cron job to roll it over, compress it, or to delete it daily/weekly
• Symbolic link to /dev/null :) -- naturally, assumes you have no interest in the console output

Customizing logging
Previously, I had talked some about customizing logging. Tomcat doesn't do Log4j, but uses a logging system called JULI. It's configuration files are a little bit different, but you should be able to pare it down without trouble.

Removing Unnecessary Parts
Under the work and webapps directory there's a series of applications that come with tomcat: (examples, manager, host-manager, docs) You can easily get rid of examples and docs, but manager and host-manager are up to you. They can be used by things like Maven to help deploy applications, so you may want to consider keeping them around.

References

• http://lifeofhumanvirus.blogspot.com/2007/03/manually-deploying-new-tomcat-web.html
• http://tomcat.apache.org/tomcat-5.5-doc/logging.html
• http://brondsema.net/blog/index.php/2006/05/25/tomcat_juli_logging_properties