What is “Pair Programming”? Is it worth doing it?
 

Pair programming is an agile software development technique in which two programmers work together at one workstation and share the same keyboard. One person (Driver) writes the code while the other person (Navigator) reviews it and at the same time thinks about the big picture.

How to do it right

  • Understand the requirement well before you start. Spend few minutes and discuss with each other.
  • Agree on one small goal at a time.
  • Support each other
    • If you are a driver, focus on small tasks and quickly complete it avoid bigger issues.  Trust navigator to your safety gate.
    • If you are a navigator, constantly review the code and think of a big picture. You don’t need to dictate the code.
  • Celebrate victory when the task is completed or you resolve a problem.
  • Changing roles few times in a day helps (Driver to Navigator and vice versa)

Do’s

  • Encourage pairing. Do not worry about slight productivity loss in beginning. This is something I have seen many teams when new teams are formed as they don’t have experience in the pairing.
  • Start with a trial. Do not force individuals to pair. Let them decide who wants to pair with whom.  Changing pairs constantly helps.
  • Pairing for more than six hours a day is not advisable.
  • Individuals should switch driver and navigator role when they get bored.
  • The Large monitors and good leg room are essential along with co-location which is absolutely mandatory.
  • Trust and support each other.  The team culture plays a critical role.

Benefits

  • Improves software quality without impacting time to deliver.
  • The focus and energy involved are much higher hence chances of making mistakes reduces significantly.
  • The better articulation of complexities and hidden details of coding tasks reduces the human errors.
  • The requirement elaboration and definition of done usually be better understood.
  • Build trust and help individuals to be better skilled.
  • The partners can switch when frustrated or stuck. The work doesn’t get compromised. The change in responsibilities once again adds energy to work.
  • New recruits come up to speed more rapidly in a pairing environment.
  • From a developer standpoint, pairing is enjoyable and valuable activity. I have seen developers who resisted pairing the first time, eventually loved it and found it to be much really useful in terms of learning, more engagement, better quality and successful careers.

Challenges

  • It’s social skill and it takes a time to do it. The best pair programmers exactly know when to say let’s try your idea first. Do not expect the outcome of pair programming from day one. It takes some time to do it in right way.
  • No benefits are expected if both the programmers are not actively engaging themselves. It’s “programming it loud’ methodology” hence it is essential that the driver and navigator constantly communicating. The silence kills the benefits of pairing.
  • If the two people have personal challenges, the pairing cannot be forced upon. The trust and mutual understanding between the two people is absolutely necessary
  • Experience mismatch is another bigger challenge. The senior programmers often want to have more control and give a little room to junior programmers.
  • View pairing as one person watching, the other person doing the actual work. That becomes boring and disengages the person watching, eliminating any real benefit from this practice.
  • Pairing should be avoided for very simple tasks or tasks which are very clear and can be done in little time.
  • Pairing needs to be done by two. The moment the third person added to it,  it cannot be called pairing anymore.
  • The co-location is absolutely mandatory. The absence of co-location where the work is shared between two programmers is called sharing over pairing.
  • Force the pairs or identify them ahead of time which may not be right in many scenarios. The best approach is to let the pairs form and swap by their own.

Myths

  • The pair programming is mentoring while it should never be. Programmers often pair with somebody with the goal to learn technology and domain. That is called either mentoring or knowledge transfer. This should be treated as a knowledge transition and expecting less than one person productivity is a fair expectation.
  • Two people working on the same story but different tasks individually is considered pairing while IT IS NOT! It is sharing the work but not pairing.
  • I have often seen individuals complete half the task and hand that over to another team member in the evening sitting in a different country and assume that it’s pairing. This is again the sharing of work and comes with an extra cost due to unknowns, handoff, and understanding each other’s work.
  • Doing agile requires pair programming. The reality is Agile manifesto never talks about pair programming.
  • The initial resistance of programmers that pairing is not the right thing to do. Most programmers like it when they try it.  Others don’t do it right and start believing it’s a waste.
  • The pairing would reduce productivity to half. This is one of the most debated topics.  I have personally experienced that when it is done in the right way, it improves the overall productivity of more than two people working individually.
What is an Agile Roadmap? What happens before sprint starts?
 

The agile roadmap is often confused with product roadmap or scrum ceremonies. The agile roadmap is indeed much beyond that. If it is not just the scrum activities then the question arises in terms of what is agile roadmap all about?  How important is it to know what happens before sprint planning? For most of us, sprint planning is the beginning of agile project while it is not (Practically it can be considered as mid-stage). A lot happen before ‘sprint’ ceremonies.   The agile roadmap would probably answer the entire process that is being followed to accomplish the project.

At a very abstract level, the agile roadmap has 7 phases listed as below:-

Vision

  • Product Owners in conjunction with senior leadership identifies the product vision.
  • The product vision talks about – What your product is, and what it entails? How it would support your company or organization strategy and who is going to consume it.

There are many more factors being considered here including the market, complexity, feasibility etc. Typically in this phase there is little or no involvement for the core development team.

Best practices

  • Touch base with your management and be updated with the vision of the product.
  • Provide inputs whenever applicable.

Product Roadmap

  • This phase defines high level of product requirements which are written at high level (EPICs).
  • Typically the EPICs are elaboration to have clarity while the stories may or may not be written.
  • The prioritization of EPICs happen as well in this phase.
  • The discussion between product owner and other stakeholders enable PO to define
    • High level estimates (Probably ROM -> +/- 30%).
    • Priorities

Best practices

  • Try to get involved in roadmap discussions.
  • Stay in touch with product management and ensure you know whats coming. What the organization goal is and what can we do to ensure we meet it.
  • Provide as much inputs as possible to product management to ensure the EPICs are well elaborated and understood.

Release Planning

  • The EPICs are further broken down into individual stories.
  • An agile project will have multiple releases with the highest priority features being picked up in order.
  • During this phase release timing for the specific product is determined.
  • The release plan must have to be created at the beginning of the project.
  • The number of sprints, team staffing and capacity is being looked at as well.
  • The estimation here is going to be +/- 10%. This is very important as the exact cost/schedule of the product/project is determined at the phase.

Best Practices

  • Every agile team must put in efforts to get involved in this phase.  The solid understanding in this phase is core to success of the product/project.
  • Identify impediments and provide inputs for estimation.

Sprint Planning/Grooming

  • The sprint team works with PO to groom the requirements based on priority.
  • Technical and product dependencies are discussed.
  • Individual tasks are created for each requirement. The next level of estimates are created (+/- 20%). Planning poker, relative estimate, and WBD are quite commonly used to provide an estimation. Based on the maturity or project and organization in the specific area, complexity based estimation can be utilized as well.
  • The team gives commitment by looking at the capacity and next level of estimates.

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Best practices

  • If the requirements are clearly stated or acceptance criteria is not written ask PO to do the same.
  • The grooming should be a constant activity and should be done for most of the stories prior to sprint start date.
  • The goal of the planning is to ensure everyone is aligned with details for each story, estimation and sprint commitment.  The planning can be done a day before sprint start date or on sprint start date.
  • The sprint commitment, assumptions and high level discussions should be sent to whole team.
  • The previous sprint must be closed before the next sprint start date. In addition to that the summary of the previous sprint to be sent to all the team members.
  • There should be a goal of N+2 sprint readiness which is to ensure that 2 sprint worth of work is groomed in advanced.
  • Make use of capacity planner for sprint commitment.

Daily Stand-ups

  • It should get completed in less than 10 minutes.
  • This meeting should answer
    • What did you do yesterday?
    • What are you going to do today?
    • Any impediment? If yes, then what is that?
  • Please note that standup meetings are not planning or technical discussion meetings. These are neither meant for micromanagement nor a meeting to provide a status.

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Best Practices

  • The standup should be time-bound. It should get completed in 10 minutes for less for 10 member team.
  • Any design or technical discussion should happen post standup. Not everyone needs to participate unless absolute necessary.
  • The standup should happen in morning. If there is a dependency with onshore counterpart, it should happen twice in a day.

Sprint Demo

  • This is essentially the demonstration of the working product (or “showcase”). This should happen post QA or peer testing.

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Best practices

  • This is a continuous activity and should be done as and when the story is done-done.
  • No story should be mark done without a demo. In case if the PO is not available, you should give the demo to rest of the team, record the session and share with a PO.

Retrospective

  • This happens at the end of the sprint. All the stakeholders sit together and discuss
    • Things which worked well
    • Areas for Improvement or things which we should stop doing it
    • Action Items
  • This meeting should also look at the action items of the previous retrospective and see where we stand. If the previous action items are not addressed, those should be included in current retrospective.

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Best practices

  • The retro must happen after every sprint. The retro should begin with action items of previous sprint.
  • There should be owner for each action item.
  • Be open. Appreciate people and discuss areas of improvement/things which did not work.

Many times the first three phases are ignored by agile teams.  The ultimate success requires or expects that the entire agile team to be well versed with first 3 phases as well. They should be part of it from day one.

Common best practices

  • Be open and honest. Support team work over individual contribution.
  • More the co-location better the outcome. Avoid working from home and silos.
  • Constantly review burn down chart to see where we stand.
  • Pick approx. 20% of tech debt in every sprint.
  • Focus on continuous improvement. That’s good for a company and for your growth.
  • Go to with pair programming wherever there is a possibility.
Perspective Designing
 

Recently, I was working with a colleague in refactoring one of our projects. As we added tests, we found few code issues and continued refactoring. Was feeling happy as our unit tests were rearing benefits. However, we know TDD or unit testing does not guarantee clean code. As we progressed, the naming conventions consumed a lot of our time. And eventually, it brought us to a discussion about why specific naming conventions can create a better design. Thought I will share our discussions and practices here.

While we design classes for application, we often think of it as a different subject than ourselves (programmer). When I say different subject, we think of it as a different object and not as a person. When a programmer considers classes/interfaces as personalities and thinks from the perspective of the class, design can change drastically. This is what we call “Perspective designing”. Let’s take an Example:

    public interface ITotalTaxCalculator
    {
        decimal Calculate(IEnumerable products);
    }

    public class TotalTaxCalculator : ITotalTaxCalculator
    {
        public decimal Calculate(IEnumerable products)
        {
            decimal total = 0.0;
            //add total of products etc....
            foreach (var product in products)
        	{
                using(var dbContext = new ProductContext())
                {
                    var productInDb = dbContext.FistOrDefault(prod => prod.Id == product.Id)
                    total += (total * productInDb.taxRate);
                }
        	}
            return total;
        }
    }

In the above example, the name of the class and interface are perfectly fine. But they are impersonal and it’s very hard to think of it as a person and bring in perspective thinking with these names. So we refactored them to ‘ICanCalculateTotalTax’ and  ‘TotalTaxMan’.

public interface ICanCalculateTotalTax
{
    decimal Calculate(IEnumerable products);
}

public class TotalTaxMan : ICanCalculatorTotalTax
{
    public decimal Calculate(IEnumerable products)
    {
        decimal total = 0.0;
        //add total of products etc....
        //blah blah blah..
        total += (total * taxRate);
        return total;
    }
}

These naming conversions have lots of inspiration from in NServiceBus for their class/Interface names. With the new class and interface names, it’s easy to think of them as personalities. However, this does not guarantee good design. So we needed refactoring. Perspective thinking comes in handy especially while we do refactoring When my colleague and I started putting ourselves in the place of each of the classes. We had very reasonable questions which triggered our object-oriented thinking.

Example1:  As ‘ICanCalculateTotalTax’ , why I am having database related behavior?

Example2: As ‘ICanCalculateTax’, why I am having logic to find which language it needs to be presented?

These questions helped us to refactor the code to follow good design principles. When we implement these interfaces/abstract classes, we have clarity on what the class is capable of doing. So we generalized these naming conventions & questioning attitude and derived below two rules to do Perspective designing (think like a class).

  • Give personality to the names of  classes/interfaces (example: ICanCalculateTax)
  • Use the Agile User Stories way of articulating what the class should and should not do. (example: As ‘ICanCalculateTax’, I should be able to provide behavior to calculate tax)

I think, “Perspective designing” can make classes more object-oriented and best practice like SOLID principles automatically fall in line. Let me know your thoughts.