Programmer Competency Matrix

Programmer Competency Matrix

Note that the knowledge for each level is cumulative; being at level n implies that you also k Level for self evaluation may range from -1.0 (I hate this) to 4.0 (I'm way above this)

Compu 2 (Level 0) Doesn't know the difference between Array and LinkedList n

data structures

algorithms

Unable to find the average of numbers in an array (It's hard to believe but I've interviewed such candidates)

systems programming

Doesn't know what a compiler, linker or interpreter is

Software 2 (Level 0) Folder backups by date n

source code version control build automation

Only knows how to build from IDE

automated testing

Thinks that all testing is the job of the tester

Prog 2n (Level 0) problem decomposition Only straight line code with copy paste for reuse

systems decomposition Not able to think above the level of a single file/class

communication

Cannot express thoughts/ideas to peers. Poor spelling and grammar.

code organization within a file

no evidence of organization within a file

code organization across files

No thought given to organizing code across files

source tree organization

Everything in one folder

code readability

Mono-syllable names

defensive coding

Doesn't understand the concept

error handling

Only codes the happy case

IDE

Mostly uses IDE for text editing

API

Needs to look up the documentation frequently

frameworks

Has not used any framework outside of the core platform

requirements

Takes the given requirements and codes to spec

scripting

No knowledge of scripting tools

database

Thinks that Excel is a database

Exp languages with professional experience

2n (Level 0) Imperative or Object Oriented

platforms with 1 professional experience years of professional experience domain knowledge

1 No knowledge of the domain

Kno tool knowledge

2n (Level 0) Limited to primary IDE (VS.Net, Eclipse etc.)

languages exposed to

Imperative or Object Oriented

codebase knowledge

Has never looked at the codebase

knowledge of upcoming Has not heard of the upcoming technologies technologies platform internals

Zero knowledge of platform internals

books

Unleashed series, 21 days series, 24 hour series, dummies series...

blogs

Has heard of them but never got the time.

y Matrix

h level is cumulative; being at level n implies that you also know everything from the levels lower than n. nge from -1.0 (I hate this) to 4.0 (I'm way above this)

Computer Science n (Level 1) Able to explain and use Arrays, LinkedLists, Dictionaries etc in practical programming tasks

n (Level 2) 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. Basic sorting, searching and data Tree, Graph, simple greedy and structure traversal and retrieval divide and conquer algorithms, is algorithms able to understand the relevance of the levels of this matrix. 2

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.

Software Engineering

n (Level 1) n (Level 2) 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. Knows how to build the system Can setup a script to build the from the command line basic system 2

Has written automated unit tests Has written code in TDD manner and comes up with good unit test cases for the code that is being written

Programming n2 (Level 1) Able to break up problem into multiple functions

n (Level 2) Able to come up with reusable functions/objects that solve the overall problem

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.

Peers can understand what is being said. Good spelling and grammar.

Is able to effectively communicate with peers

Methods are grouped logically or by accessibility

Code is grouped into regions and well commented with references to other source 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.

Basic separation of code into logical folders.

No circular dependencies, binaries, libs, docs, builds, thirdparty code all organized into appropriate folders

Good names for files, variables classes, methods etc.

No long functions, comments explaining unusual code, bug fixes, code assumptions

Checks all arguments and asserts Makes sure to check return values critical assumptions in code and check for exceptions around code that can fail. Basic error handling around code Ensures that error/exceptions that can throw leave program in good state, exceptions/generate errors resources, connections and memory is all cleaned up properly

Knows their way around the interface, able to effectively use the IDE using menus. Has the most frequently used APIs in memory

Knows keyboard shortcuts for most used operations. Vast and In-depth knowledge of the API

Has heard about but not used the Has used more than one popular frameworks available for framework in a professional the platform. capacity and is well-versed with the idioms of the frameworks. Come up with questions regarding Understand complete picture and missed cases in the spec come up with entire areas that need to be speced Batch files/shell scripts

Perl/Python/Ruby/VBScript/Powers hell Knows basic database concepts, Able to design good and normalization, ACID, transactions normalized database schemas and can write simple selects 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 nonclustered indexes. Proficient in use of ORM tools.

Experience n2 (Level 1) Imperative, Object-Oriented and declarative (SQL), added bonus if they understand static vs dynamic typing, weak vs strong typing and static inferred types 2-3

n (Level 2) Functional, added bonus if they understand lazy evaluation, currying, continuations

2-5

6-9

Has worked on at least one product in the domain.

Has worked on multiple products in the same domain.

4-5

Knowledge n2 (Level 1) n (Level 2) Knows about some alternatives to Good knowledge of editors, popular and standard tools. 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. Imperative, Object-Oriented and Functional, added bonus if they declarative (SQL), added bonus if understand lazy evaluation, they understand static vs currying, continuations dynamic typing, weak vs strong typing and static inferred types

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 heard of upcoming technologies in the field

Has downloaded the alpha preview/CTP/beta and read some articles/manuals

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. Design Patterns, Peopleware, Programming Pearls, Algorithm Design Manual, Pragmatic Programmer, Mythical Man month

Code Complete, Don't Make me Think, Mastering Regular Expressions

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

s lower than n. Weight log(n) (Level 3) Knowledge of advanced data structures like B-trees, binomial and fibonacci heaps, AVL/Red Black trees, Splay Trees, Skip Lists, tries etc.

Comments

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. 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...

Working with someone who has a good topcoder ranking would be an unbelievable piece of luck!

log(n) (Level 3) Knowledge of distributed VCS systems. Has tried out Bzr/Mercurial/Darcs/Git

Comments

1

1

1

1

Can setup a script to build the system and also documentation, installers, generate release notes and tag the code in source control

1

Understands and is able to setup automated functional, load/performance and UI tests

1

log(n) (Level 3) Use of appropriate data structures and algorithms and comes up with generic/objectoriented code that encapsulate aspects of the problem that are subject to change.

Comments 1

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. Able to understand and communicate thoughts/design/ideas/specs in a unambiguous manner and adjusts communication as per the context

File has license header, summary, well commented, consistent white space usage. The file should look beautiful. Code organization at a physical level closely matches design and looking at file names and folder distribution provides insights into design Physical layout of source tree matches logical hierarchy and organization. The directory names and organization provide insights into the design of the system.

1

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.

1

1

1

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.

1

Code assumptions are verified using asserts, code flows naturally - no deep nesting of conditionals or methods Has his own library to help with defensive coding, writes unit tests that simulate faults 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. Has written custom macros

1

Has written libraries that sit on E.g. of API can be Java library, top of the API to simplify .net framework or the custom frequently used tasks and to fill in API for the application gaps in the API

1

1 1

1

Author of framework

1

Able to suggest better alternatives and flows to given requirements based on experience Has written and published reusable code 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.

1

1 1

log(n) (Level 3) Comments Concurrent (Erlang, Oz) and Logic (Prolog)

1

6+

1

10+

1

Domain expert. Has designed and implemented several products/solutions in the domain. Well versed with standard terms, protocols used in the domain.

1

log(n) (Level 3) Has actually written tools and scripts, added bonus if they've been published.

Concurrent (Erlang, Oz) and Logic (Prolog)

Comments 1

1

Has implemented multiple big features in the codebase and can easily visualize the changes required for most features or bug fixes. Has played with the previews and has actually built something with it and as a bonus shared that with everyone else Has written tools to enhance or provide information on platform internals. For e.g. disassemblers, decompilers, debuggers etc.

1

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 Maintains a blog in which personal insights and thoughts on programming are shared

1

1

1

1

Self evaluation Name: Level 0.0

0.0

0.0

Comment

0.0

0.0

Self Evaluation Summary Name: 0 Competency Computer Science Software Engineering Programming Experience Knowledge

Mark 0.0 0.0 0.0 0.0 0.0

Approx. experience 0.0 0.0 0.0 0.0 0.0

Self Evaluation Le

Computer Scienc 1.0 0.8

Global

0.00

0.0 0.5 Software Engineering

0.3 0.0

Programming

Self Evaluation Levels Computer Science 1.0 0.8 0.5

ng

Knowledge

0.3 0.0

Programming

Experience

Table of experience approximation according to competency level

28 26 24 Approximative years of experience

Competency Approximative Formula level years of experience 0 0.0 2^n-1 0.1 0.1 2^n-1 0.2 0.1 2^n-1 0.3 0.2 2^n-1 0.4 0.3 2^n-1 0.5 0.4 2^n-1 0.6 0.5 2^n-1 0.7 0.6 2^n-1 0.8 0.7 2^n-1 0.9 0.9 2^n-1 1 1.0 (n-1)^2+2^n-1 1.1 1.2 (n-1)^2+2^n-1 1.2 1.3 (n-1)^2+2^n-1 1.3 1.6 (n-1)^2+2^n-1 1.4 1.8 (n-1)^2+2^n-1 1.5 2.1 (n-1)^2+2^n-1 1.6 2.4 (n-1)^2+2^n-1 1.7 2.7 (n-1)^2+2^n-1 1.8 3.1 (n-1)^2+2^n-1 1.9 3.5 (n-1)^2+2^n-1 2 4.0 (n-2)+(n-1)^2+2^n-1 2.1 4.6 (n-2)+(n-1)^2+2^n-1 2.2 5.2 (n-2)+(n-1)^2+2^n-1 2.3 5.9 (n-2)+(n-1)^2+2^n-1 2.4 6.6 (n-2)+(n-1)^2+2^n-1 2.5 7.4 (n-2)+(n-1)^2+2^n-1 2.6 8.2 (n-2)+(n-1)^2+2^n-1 2.7 9.1 (n-2)+(n-1)^2+2^n-1 2.8 10.0 (n-2)+(n-1)^2+2^n-1 2.9 11.0 (n-2)+(n-1)^2+2^n-1 3 12.0 log(n-3+1)+(n-2)+(n-1)^2+2^n-1 3.1 13.1 log(n-3+1)+(n-2)+(n-1)^2+2^n-1 3.2 14.3 log(n-3+1)+(n-2)+(n-1)^2+2^n-1 3.3 15.6 log(n-3+1)+(n-2)+(n-1)^2+2^n-1 3.4 16.9 log(n-3+1)+(n-2)+(n-1)^2+2^n-1 3.5 18.2 log(n-3+1)+(n-2)+(n-1)^2+2^n-1 3.6 19.7 log(n-3+1)+(n-2)+(n-1)^2+2^n-1 3.7 21.2 log(n-3+1)+(n-2)+(n-1)^2+2^n-1 3.8 22.8 log(n-3+1)+(n-2)+(n-1)^2+2^n-1 3.9 24.5 log(n-3+1)+(n-2)+(n-1)^2+2^n-1 4 26.3 log(n-3+1)+(n-2)+(n-1)^2+2^n-1

22 20 18 16 14 12 10 8 6 4 2 0 0

petency level

Programmer Competency Matrix Level

1

2 level according to Programmer Competency Matrix

3

4

Authors Original version Sijin Joseph April 2008 Web version John Haugeland February 2009 Excel version Michel Bagnol July 2009

http://weblogs.asp.net/sjoseph/archive/2008/04/30/programmer-compe http://www.indiangeek.net/programmer-competency-matrix/ http://www.nodewave.com/programmer-competency-matrix

08/04/30/programmer-competency-matrix.aspx mpetency-matrix/ ompetency-matrix