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What can a senior developer do that a junior developer can’t do?

I saw this post about senior vs junior lawyers a while ago and it sparked some thoughts about the senior/junior divide.  I have also seen companies interested in hiring only senior developers. This is not a post hating on junior developers–the only path to a senior developer is starting as a junior developer.

Anyway, I think that senior developers will help you in a number of ways:

  • Senior developers have made their mistakes on someone else’s dime.  We all make mistakes.  One time I took 4 hours to figure out that the reason I couldn’t connect to an Amazon RDS instance was because the security group was too locked down.  But people integrate their mistakes into their experience and don’t make the same mistake twice.  When you hire a senior developer, you’re getting all their previous experience as well as their current effort.
  • Senior developers can own a larger portion of a project than junior can.  This can include non coding tasks like system setup, estimation, requirements definition and customer interaction.  This gives you leverage.
  • They are able to understand interactions between various pieces of your system.
  • They have an intuitive feel for performance impacts, again, probably because of previous mistakes.
  • They map your current solutions and problems into their existing knowledge: “Oh, this is how we handled caching at my <$JOB – 2>.”
  • They bring best practices from other companies (and can comment on worst practices).
  • They can get up to speed more quickly.
  • They can mentor other developers in areas of expertise.
  • They know the power of automation and knowledge sharing.
  • They have previously been confronted with difficult, complex problems and have an idea of how to attack new, difficult complex problems.
  • They understand that almost all problems are people problems, and that communication is a key part of any project’s success.

Junior developers, in my experience, bring value for the money as well.

  • They have more malleable viewpoints, especially with respect to tooling and technology.
  • They are typically very eager to learn.
  • When you are explaining systems to them, they can’t leverage existing knowledge.  This forces you to speak from first principles and may highlight erroneous assumptions.
  • Because they don’t have the knowledge of existing systems, they question why things are done a certain way.  Systems and processes evolve, but sometimes tasks are done only because they’ve “always been done that way” which isn’t necessarily the most efficient.  It’s hard to see that without the “eyes of a beginner”.
  • They are less cynical.

All good developers in my mind are:

  • Eager to learn.
  • Unwilling to say “that’s not my job”.
  • Accept ownership of the success of the project and the business.

If I had to sum up the differences between junior and senior developers in one word, it is would be “scope”.  A senior developer should be able to handle a wider scope of projects, responsibilities and problems than a junior developer.  How wide that scope is depends on the developer, their experience, and the problem space, but there are certain aspects of scope that are the same across domains (non coding tasks).

Business Programming | moore | | Leave a comment

The Rails Low Level Cache

I think the Rails low level cache is the bees knees. It lets you store complicated values easily, manage TTLs, and improve the performance of your application.

I’d be remiss in stating that you shouldn’t cache until you need to.  Caches will introduce additional complexity into your application, make troubleshooting harder, and in general can be confusing.  How do you know if you need to introduce a cache?  Profile.  Using rack-mini-profiler is a great quick and dirty way to profile your code.

The rails low level cache is fairly simple to configure (especially if you’re using a PaaS like Heroku–you can drop in a managed memcached service easily).

From there, you need to build a cache key.  This is a string, up to 250 characters in length, that uniquely identifies whatever you’re trying to cache.  Basically anything that would cause a change in the contents of the cached object should be included in this key.  However, since you are going to calculate this key every time the value is requested, you don’t want the cache key to be expensive to calculate, otherwise the value of the cache will be degraded.  Good things for the key: timestamps, max updated_at values for a collection, user ids or roles.

Then, putting a value in the cache is as easy as:

def pull_from_cache
  cache_key = 'mykeyval'
  myval = Rails.cache.fetch(cache_key, expires_in: 1.hours) do
      @service.build_expensive_object()
  end
end

In the case above, the cached value will automatically expire in 1 hour.  If you don’t set the expiration time, then the cached value will eventually be removed via LRU.  How long that is depends on the size of your cache and what else you are putting in there.

If you want to test that something is being put in the cache, you can run a unit test and see how many times build_expensive_object() is called.

#...
object.service = @service
expect(@service).to receive(:build_expensive_object).once
object.pull_from_cache  
object.pull_from_cache
#...

In a production troubleshooting situation, you may need to evict something from the cache.  You can do so from the rails console by finding the cache key and running Rails.cache.delete('key').

Using the low level cache is a great way to push read heavy hot spots of your rails application (database queries or other complicated calculations) into memory and make your application faster.

Rails | moore | | Leave a comment

Online teaching tips for synchronous classrooms

I’ve been teaching AWS courses for the past year or so.  Many have been with an online teaching environment.  This opens up the class to more people–there’s less cost in taking a course from your office or living room, as compared to flying an instructor out for an on-site.  However, this learning environment does have challenges.  Below is my set of best practices, some suggested by other instructors.

Pre class:

  • Set up your physical environment.  This includes making sure you have a fast internet connection, a room with no noise, and that your computer and audio equipment are set up.
  • Set up the virtual room.  Load the materials, set up any links or other notes.  I like to run virtual courses entirely with chat (audio conferences are really hard with 20 people) so I make a note about that.
  • Test your sound.  This includes having a friend login and listen to you beforehand.  This run through can help make sure your voice (which is your primary engagement tool) is accessible to your students.
  • Email a welcome message to all the students, 2-3 days before class starts.  Include when the class is happening, how to get materials, etc.  I’ve definitely had interactions with students from these emails that led to a better outcome for everyone.

During class:

  • Calculate your latency.  Ask an initial question that requires a response as soon as the question is asked.  Something easy like “where are you from?” or “how many years of AWS experience do you have?”  Note the latency and add it into the time you wait before asking for questions.
  • Ask for questions.   How often can vary based on previous AWS experience, but every 5-10 slides is a good place to start.
  • Answer questions honestly.  If you don’t know, say so.  But then say, “I’ll find out for you.”  (And then, of course, find out.)
  • Allow time for students to read the slide.  At least 15 seconds for each slide.
  • You, however, should not read the slide.
  • Draw or use the pointer tool to help engage the students and pull them into the material.
  • Find out what students want out of the class.  Try to angle some of the content toward those desires.  You may be constrained by knowledge or time or presentation material, but you can at least try.
  • Engage your students.  I like to make corny jokes (“have you heard the one about the two hard problems in computers science?“), refer back to technologies they mention having familiarity with, and talk about internet kitten pictures.
  • Remember your voice and energy are the only things keeping these students engaged.

After class:

  • Follow up on any loose ends.  This could be questions you didn’t get answered or more mundane items like how they can get a certificate of completion.  I had one student who couldn’t get access to the materials and it took a few weeks of bugging customer service reps across organizations before he did.  Not a lot of time on my end, but a big deal for him.

Note that I didn’t cover the content or particular technology at all.  They aren’t really relevant.

 

AWS Presentations | moore | | Leave a comment

Useful Rails Gems: Pretender

I’m constantly amazed at how productive you can be with rails. It simply lets you work on typical webapp problems at a much higher level. At 8z, we had a web application and a customer support team. Occasionally the customer support person had to ‘impersonate’ a normal user to troubleshoot an issue. We built a piece of software that let them assume that role. (We called it ‘sudo‘, obviously.) It’s been a few years, but as I recall it was complicated and error prone, lived on a different domain and wasn’t fully functional.

I needed to add similar functionality to a rails web app, and was able to find a couple of gems that looked useful. I selected pretender, mostly on the basis of documentation and google search results placement. I followed the instructions, tweaked a few settings and was off to the races in about an hour.  (Note this isn’t a fair apples to apples comparison of the underlying technologies, due to the differences in available open source libraries between the mid 2000s and the late 2010s.)

Now, all this gem does is what it says it does. It lets a certain user or set of users in your application pretend to be another user. It doesn’t handle auditing or anything else you might want with an elevated privilege system.

But it does do what it does well.

8z Business Consulting Rails | moore |

Ask the hard questions

Do you know that moment which happens at almost every meeting or conference call, when a participant refers to a concept that you don’t quite understand?  That moment happens to me often, and has throughout my career.

“The marketing funnel is part of the sales process.”

“We can just flurbuzz the bazznod.”

“We have plenty of runway.”

That is the moment when you can ask the hard question.

“Why is that connected?”

“What does that mean?”

“I’m sorry, I don’t understand.  Could you repeat that?  How do you define runway?”

Asking these questions is important.  Otherwise you and the other parties will be talking past each other, which will only lead to pain down the line when the misunderstanding is crystallized in people, process or code.

I’ve been asking these kinds of questions my entire career.  When I worked at a web consulting company in the early 2000s, there were often company wide conference calls discussing our precarious financial state.  I got a reputation as “the question guy” because I wasn’t afraid of asking the awkward question, even of the CEO in front of the entire company.  I was interested in hearing as real of an answer (as they could share).

If you’re interested in asking hard questions, here are some tips:

  • Pay attention beforehand.  If you are asking a question about something that was just mentioned, or that you should have known, you won’t have credibility.
  • Don’t worry about looking dumb (except if you weren’t paying attention, see above).  If it is a fuzzy concept, chances are others in the room are wondering what it is.  Besides, the goal is to increase your knowledge.  Check your ego.
  • Ask the question from a place of humility and make it about you.  Maybe you just really don’t understand.  I always like the phrase: “I’m sorry, I don’t understand what you just said.”
  • Approach with positive intention.  Don’t ask gotcha questions or try to prove you are smarter than the speaker.
  • If the answer is a bit fluffy or you don’t understand it, ask a second time.  “Thanks, but I’m afraid I still don’t get it.  Could you explain it to me again?”
  • If the speaker doesn’t answer or hedges again, offer to take it offline.  Depending on who is in the meeting, you don’t want to waste everyone’s time.  But then make sure you follow up.
  • Recognize if the topic is sensitive (financial matters) you may not get a clear answer.  At that point, getting the speaker to define terms but perhaps omit numbers is a win.

Again, the goal here is not to ‘get’ the speaker, it’s to help get everyone on the same page.  Asking tough questions to pin down some of the nebulous concepts we work with every day can help everyone make better decisions.

Business Tips | moore | | Leave a comment

Reference checking: not just for VCs and employers

Fred Wilson has a great post on reference checking.  From the post:

The thing I have learned in thirty plus years of making reference calls is to pay attention to how things are said more than what is said. And pay particular attention to what is not said.

As always, there’s a number of great stories in the comments, including “warm up your network” when you are going to be referenced checked, and the story of a reference check poaching a candidate.

However, reference checks aren’t just for CEOs, hiring managers and VCs.  They are a powerful tool for job candidates.  It is tedious and time intensive, but is an additional source of information about a company for which you are considering working.  LinkedIn is in particular very useful here, because if you are thinking about working for company XYZ you can find out not only who works now for them, but also who used to work for company XYZ.  You can also find out who knows someone who knows someone who used to work for them.  Yes, this takes additional time, but if you’re going to be spending 40+ hours a week at a company, isn’t it worth gaining some perspective from people who are or were on the inside?

Consider it one more method of doing your research.

 

Business | moore | | Leave a comment

When doing a startup, don’t forget to calculate emotional runway as well as financial runway

When I joined The Food Corridor, the concept of financial runway was well known to me from my consulting days.  You figure out your monthly expenses, your savings, and any income you have coming in.  Divide your savings (or at least the amount you want to spend) by the expenses less the income, and you get the amount of time available to work on the startup before you run out of money.

You definitely want to pad this a bit, because if you run out of money, you’ll need some time to find another source of income.  You can also pad this with debt, selling other assets, part time work, investment, etc.  Heck, maybe the startup will even make some money too.

But the goal is to have an idea of how long you can go before you have to call it quits for financial reasons.  Then you can see if you think you can build the company in that amount of time.  (Hint, it’s going to take longer than you think to build the company.)

Emotional runway is another key aspect of surviving a startup.  Startups are full of a lot of stress.  Some examples:

  • Making decisions on limited data
  • Dealing with a product that is broken because of the speed at which you built it
  • Screwing up and apologizing to customers for said screwup
  • Dealing with financial uncertainty
  • Hiring
  • Firing
  • Limited or nonexistent support structure
  • Trying to figure out how to build a company
  • Personnel conflicts
  • Missing family time because of work
  • Lack of vacation/benefits
  • And, of course, the possibility of running out of money

All of the above make it tough to ‘tough out’ a startup.  These are all costs that you will have to bear.  Just like you only have a certain amount of savings to spend down, you also only have a certain amount of emotional wealth to spend.  (There are times when a startup will deliver emotional wealth too.)

One of the hardest parts of the current startup for me is keeping an eye on my emotional runway.  Taking some time off, celebrating successes, being open about the stresses with co-founders and family, and just being aware of what puts “money” into the emotional piggy bank and what takes it out are all ways I’ve dealt with this.

Business The Food Corridor | moore | | Leave a comment

Railsconf Call For Proposals

Railsconf, a conference focused on, well, Ruby on Rails, is happening in Pittsburgh in April this year.  I attended last year and it was a fantastic experience.  I enjoyed the people I met, the problems I saw discussed, and the size and content of the presentations and workshops.  It definitely had a vendor experience (thank you, Heroku, for the t-shirts), but wasn’t too explicit.

Railsconf organizers are now accepting proposals for workshops, panels and speaking.  For some reason the CFP isn’t on the website, but I noticed it was announced via twitter.  I just submitted, so I can’t speak to the entire process, but the initial submission was pretty painless, just few sections on what you’re interested in presenting and why you might be a good fit.

They actually have a blind submission format, so I had to edit my initial submission to remove any reference to my identity.  Seems like a good idea.

So, go forth and submit!

Presentations Rails | moore | | Leave a comment