A Pragmatic Quick Reference.
- Care About Your Craft
Why spend your life developing software unless you care about doing it well?
- Think! About Your Work
Turn off the autopilot and take control. Constantly critique and appraise your work.
- Provide Options, Don’t Make Lame Excuses
Instead of excuses, provide options. Don’t say it can’t be done; explain what can be done.
- Don’t Live with Broken Windows
Fix bad designs, wrong decisions, and poor code when you see them.
- Be a Catalyst for Change
You can’t force change on people. Instead, show them how the future might be and help them participate in creating it.
- Remember the Big Picture
Don’t get so engrossed in the details that you forget to check what’s happening around you.
- Make Quality a Requirements Issue
Involve your users in determining the project’s real quality requirements.
- Invest Regularly in Your Knowledge Portfolio
Make learning a habit.
- Critically Analyze What You Read and Hear
Don’t be swayed by vendors, media hype, or dogma. Analyze information in terms of you and your project.
- It’s Both What You Say and the Way You Say It
There’s no point in having great ideas if you don’t communicate them effectively.
- DRY – Don’t Repeat Yourself
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
- Make It Easy to Reuse
If it’s easy to reuse, people will. Create an environment that supports reuse.
- Eliminate Effects Between Unrelated Things
Design components that are self-contained. independent, and have a single, well-defined purpose.
- There Are No Final Decisions
No decision is cast in stone. Instead, consider each as being written in the sand at the beach, and plan for change.
- Use Tracer Bullets to Find the Target
Tracer bullets let you home in on your target by trying things and seeing how close they land.
- Prototype to Learn
Prototyping is a learning experience. Its value lies not in the code you produce, but in the lessons you learn.
- Program Close to the Problem Domain
Design and code in your user’s language.
- Estimate to Avoid Surprises
Estimate before you start. You’ll spot potential problems up front.
- Iterate the Schedule with the Code
Use experience you gain as you implement to refine the project time scales.
- Keep Knowledge in Plain Text
Plain text won’t become obsolete. It helps leverage your work and simplifies debugging and testing.
- Use the Power of Command Shells
Use the shell when graphical user interfaces don’t cut it.
- Use a Single Editor Well
The editor should be an extension of your hand; make sure your editor is configurable, extensible, and programmable.
- Always Use Source Code Control
Source code control is a time machine for your work – you can go back.
- Fix the Problem, Not the Blame
It doesn’t really matter whether the bug is your fault or someone else’s – it is still your problem, and it still needs to be fixed.
- Don’t Panic When Debugging
Take a deep breath and THINK! about what could be causing the bug.
- “select” Isn’t Broken.
It is rare to find a bug in the OS or the compiler, or even a third-party product or library. The bug is most likely in the application.
- Don’t Assume It – Prove It
Prove your assumptions in the actual environment – with real data and boundary conditions.
- Learn a Text Manipulation Language.
You spend a large part of each day working with text. Why not have the computer do some of it for you?
- Write Code That Writes Code
Code generators increase your productivity and help avoid duplication.
- You Can’t Write Perfect Software
Software can’t be perfect. Protect your code and users from the inevitable errors.
- Design with Contracts
Use contracts to document and verify that code does no more and no less than it claims to do.
- Crash Early
A dead program normally does a lot less damage than a crippled one.
- Use Assertions to Prevent the Impossible
Assertions validate your assumptions. Use them to protect your code from an uncertain world.
- Use Exceptions for Exceptional Problems
Exceptions can suffer from all the readability and maintainability problems of classic spaghetti code. Reserve exceptions for exceptional things.
- Finish What You Start
Where possible, the routine or object that allocates a resource should be responsible for deallocating it.
- Minimize Coupling Between Modules
Avoid coupling by writing “shy” code and applying the Law of Demeter.
- Configure, Don’t Integrate
Implement technology choices for an application as configuration options, not through integration or engineering.
- Put Abstractions in Code, Details in Metadata
Program for the general case, and put the specifics outside the compiled code base.
- Analyze Workflow to Improve Concurrency
Exploit concurrency in your user’s workflow.
- Design Using Services
Design in terms of services – independent, concurrent objects behind well-defined, consistent interfaces.
- Always Design for Concurrency
Allow for concurrency, and you’ll design cleaner interfaces with fewer assumptions.
- Separate Views from Models
Gain flexibility at low cost by designing your application in terms of models and views.
- Use Blackboards to Coordinate Workflow
Use blackboards to coordinate disparate facts and agents, while maintaining independence and isolation among participants.
- Don’t Program by Coincidence
Rely only on reliable things. Beware of accidental complexity, and don’t confuse a happy coincidence with a purposeful plan.
- Estimate the Order of Your Algorithms
Get a feel for how long things are likely to take before you write code.
- Test Your Estimates
Mathematical analysis of algorithms doesn’t tell you everything. Try timing your code in its target environment.
- Refactor Early, Refactor Often
Just as you might weed and rearrange a garden, rewrite, rework, and re-architect code when it needs it. Fix the root of the problem.
- Design to Test
Start thinking about testing before you write a line of code.
- Test Your Software, or Your Users Will
Test ruthlessly. Don’t make your users find bugs for you.
- Don’t Use Wizard Code You Don’t Understand
Wizards can generate reams of code. Make sure you understand all of it before you incorporate it into your project.
- Don’t Gather Requirements – Dig for Them
Requirements rarely lie on the surface. They’re buried deep beneath layers of assumptions, misconceptions, and politics.
- Workwith a User to Think Like a User
It’s the best way to gain insight into how the system will really be used.
- Abstractions Live Longer than Details
Invest in the abstraction, not the implementation. Abstractions can survive the barrage of changes from different implementations and new technologies.
- Use a Project Glossary
Create and maintain a single source of all the specific terms and vocabulary for a project.
- Don’t Think Outside the Box – Find the Box
When faced with an impossible problem, identify the real constraints. Ask yourself: “Does it have to be done this way? Does it have to be done at all?”
- Start When You’re Ready.
You’ve been building experience all your life. Don’t ignore niggling doubts.
- Some Things Are Better Done than Described
Don’t fall into the specification spiral – at some point you need to start coding.
- Don’t Be a Slave to Formal Methods.
Don’t blindly adopt any technique without putting it into the context of your development practices and capabilities.
- Costly Tools Don’t Produce Better Designs
Beware of vendor hype, industry dogma, and the aura of the price tag. Judge tools on their merits.
- Organize Teams Around Functionality
Don’t separate designers from coders, testers from data modelers. Build teams the way you build code.
- Don’t Use Manual Procedures
A shell script or batch file will execute the same instructions, in the same order, time after time.
- Test Early. Test Often. Test Automatically
Tests that run with every build are much more effective than test plans that sit on a shelf.
- Coding Ain’t Done ‘Til All the Tests Run
- Use Saboteurs to Test Your Testing
Introduce bugs on purpose in a separate copy of the source to verify that testing will catch them.
- Test State Coverage, Not Code Coverage
Identify and test significant program states. Just testing lines of code isn’t enough.
- Find Bugs Once
Once a human tester finds a bug, it should be the last time a human tester finds that bug. Automatic tests should check for it from then on.
- English is Just a Programming Language
Write documents as you would write code: honor the DRY principle, use metadata, MVC, automatic generation, and so on.
- Build Documentation In, Don’t Bolt It On
Documentation created separately from code is less likely to be correct and up to date.
- Gently Exceed Your Users’ Expectations
Come to understand your users’ expectations, then deliver just that little bit more.
- Sign Your Work
Craftsmen of an earlier age were proud to sign their work. You should be, too.
Latest posts by Mark Hall (see all)