My Reversim Summit Experience

Reversim is an Israeli podcast that speaks about technology and the software world. In 2013 they organized the first Reversim summit - an event dedicated to sharing knowledge between tech companies. After last year's success, in February 2014 a second summit was held. The tickets were over faster than the Led-Zeppelin or the israeli Kaveret reunions (I guess that the free-entrance made it easy for people to just register and save their spot quickly, but I think that was not the main reason).

This year I got the opportunity to present my code-review talk, which I gave in Outbrain a few month ago, in front of people from other companies. For those of you who missed it, here it is:

It was very interesting to speak with people after the talk and hear their opinions about code-review, the challenges they faced and the tips they looked for.

Aside from that, there were so many great lectures and things to enjoy in the summit. For me, the most inspiring lecture was Iris Shoor's lecture that talked about how she converted her dev team to marketers. Her last year's presentation inspired me when I worked on my interview exercise for Outbrain, so I knew that I want to hear this year's talk. 
Another great talk was Oren Ellenbogen's talk: Engineering your culture- how to keep your engineers happy. Oren analyzed the qualities engineers look for in a work place and the importance of hiring the people that fit the qualities the company can offer.

Of course, I still need to catch up all the talks I couldn't attend. I believe I'm about to find a lot more interesting talks.

Aside for the regular talks, I really enjoyed the open-space about "Why do we work so hard and move so slowly?". Probably a question that each developer has asked himself/herself sometime. It was very interesting to hear the different opinions and observations to this question. For example, a lot of people talked about all the "non-working" stuff they have to do - answering emails, attend meetings, fix bugs and so on. One of the conclusions that the group reached to was that these things are also work, they also help us progress. A lot of engineers feel that progress == writing code, and not consider other valuable tasks as work which makes them feel they move too slowly.
Also we talked about the importance of retrospecting and measuring your work and other stuff like technical-debt, methodologies and so on.

Also, let us not forget a lot of other fun activities like the ignite talks in which people tried to pass on an idea in 5 minutes, the band (with the Pizza & Beer) and the (in)famous "Hall of Shame" where people exposed their most glorified failures in their career.

So, bottom-line - I really enjoyed this summit, both as a speaker and as a listener. I would recommend other colleagues to catch the videos on youtube. I'm already waiting for next year!

Find me on Twitter: @AviEtzioni

More interesting posts from this blog:

Code Review - Just Do It! (Part 3 - What's Your Excuse?)

In my last 2 posts I talked about code-review as a great feedback tool, and after that I tried to give some numbers and reasons as to why you should do it. If you got up to this post, you probably a bit more convinced about code-review. And yet, people tend to give me (and themselves) a lot of excuses as to why they shouldn't code-review. 

This final post about code-review, will be dedicated to the various excuses and their refutation.

It takes too much time

The first excuse is the one I most strongly refuse to accept. Saying that code-review takes too much time implicitly implies that it's a waste of time. In my opinion, a software-engineer's work is to provide quality code in order to allow future maintenance of the software. A lot of other things take time - like talking about and writing designs, like monitoring our app and let us not forget automatic tests that require us a lot of time as well.

Code review is not a waste of time - it's an investment of time that will later save us much more time.

I'm not familiar with the code

I relate to this excuse more as more of a "reason" or "concern". That's true, it's harder to review code that you're not familiar with. But it's much easier than you'd might expect. It's so easy to spot code-smells - too many branching in a method, long methods/classes that do much more than they should, bad-namings, irrelevant and misleading comments, etc...

Let's look at the following code:

Almost every java developer would see that concatenating over and over will cause the heap to be filled with unused objects and the GC to work harder (let's assume no compiler-optimization). These examples (maybe a bit less trivial) happen a lot, and they need you to spot them.

Another great insight you can provide would be in a form of a question. "Did you run tests?", "How does this change affect other components?" and so on. These insights are very valuable. When we code, we don't always remember the full-picture around our feature, and it's great to have someone reminding us (before we discover the issues the hard way).

It's too subjective

That's true. Code-reviews are subjective. And yet, researches show an average of 82% of agreement amongst reviewers. This means that in 82% of the times, it's not that subjective. Also, you could always add more reviewers to help you decide when there is a difference of opinions. And lastly, you don't have to agree, but at least hear what others have to say. It might be useful.

It's just a minor change

Oh, what a devious excuse is this one. No matter if we're totally noobs in software-engineering, or we're experts with 20 years of experience, we fall for this one time after time. We just wanted to change a little string, maybe even a log line and BOOM (!!!), an exception is thrown. Let's take this "minor" example:

Won't it be sad when the NullPointerException will be thrown?

In our line of work, even this minor change can cause problems. Problems that could easily be avoided during a code-review.

JUST DO IT

If you've come this far, I hope I managed to convince you that code-review is something you should embrace in your organization. The best way to start is just doing it. Stop making excuses as to why it won't work and just start. The rest will follow.

Hope you enjoyed and learned from this 3-posts-long topic. In my next post I'll talk about refactoring of legacy code. Stay tuned ;)

Find me on Twitter: @AviEtzioni

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Code Review - Just Do It! (Part 2 - What's in it for me??)

In my previous post, I talked about code-review as one of the great mechanisms we have to provide and accept feedback during our coding-process. In this post I'll try to talk about what you will really gain by code-reviewing.

Code Review (ha!) What is it good for?? (Absolutely something!)

When I try to convince people they should apply and use code-review, I tend to encounter lots of excuses. Well, perhaps it would be too accusing to say excuses, so let's say "concerns". Before addressing the various excuses (I mean, concerns) for not applying code-review as part of the development cycle, let's try and figure out why you should do code-review and what you gain from it. In my next post, I'll talk about the different excuses for refraining from it.

Defect types 

Let's try and understand what are the common defect-types code-review can reveal; In a research conducted in the University of Helsinki ("Defect Detection Efficiency: Test Case Based vs. Exploratory Testing") they tried to identify the types of issues found in a review. We can group those issues into three groups:

1. Functional - The code doesn't do what it supposed to
2. Maintainability - The code structure would be hard to maintain (classes that do too much, code style, strong coupling and so on...)
3. False positives

While one might think that the functional problems are the main problems found in a code review, turns out these problems comprise only 21% of the problems found in a review. It means that usually, when you reviewing code, the code actually works exactly how the author claims it works. The majority of the problems are the maintainability problems which comprise 71% of the problems. This means that by code-reviewing you help keeping your code clean, maintainable and defend it from rotting. 

Defect Reduction

I tried to the dig around the web for numbers of defect reduction for different methods. I wasn't able to find any concrete scientific numbers, but I did find some less-official estimations. But between pair-programming (15%-50% of defect reduction), unit-tests (30%-60%) and code-review meeting (45%-50%) - I found the method I like most, the asynchronous code-review (in which you send the diff of your changes to your peers and they respond on their own time), to be considered as the most affective one with 60%-65% of defect reduction.

Still not sure?

Even when the numbers are so solid, people often can't see what they can gain, personally, from code-reviewing. Let's take a moment to talk about that.

Why should I seek this feedback?

Better code inspection

Before I publish my changes to review, I usually take a few minutes and read it again. Ensure I haven't left out any commented code or tweaks I had done while working, making sure the variables and methods are named with readable names, and so on. I do it because I know people will dig through my code, and I don't want to embarrass myself with poor quality code. This alone, helps me find issues even before the actual code review.

Get feedback from unbiased eyes

Your code does not necessarily do what you think it does. It's also not as readable as you might expect it to be. Having someone that was not part of the code-writing, inspecting your code, reveals the true readability, and true purpose of your code.

Find your problems sooner than later

I've already met a lot of people that prefer ignoring their problems. And why won't they? You're about to finish a feature you have been working on for a few days, you can't wait for it to be committed and deployed, and now you're getting all sorts of feedbacks and comments that require you to make changes to this state-of-the-art piece of code. But the fact is that the problems aren't going anywhere. You should embrace feedback and fix your problems as soon as you find them, while your mind is still on this mission. Fixing it later will cost you more as you will try to remember and understand the things you did, and why you did them.

You'll commit and deploy your code, don't worry. You'll be even more proud of it after you have fixed the issues.

Learn new stuff

You'd be surprised about what your peers can teach you. From a simple review you can learn about design patterns, quality-patterns, performance issues, design issues and a whole lot of other stuff. Try to learn from your peers, it's important in our line of work.

Teach the others

And your peers can also learn a lot from you, if you just give them the chance. By conducting code-review, they get a chance to see how you do stuff. And they'll most probably love to learn from you.

Why should I provide feedback to others?

Improve code-reading skills

One of the most important skills for a programmer is the ability to read other people's code. Practice code-review and you'll see how it allows you to get into new-code in no-time.

Learn new stuff

I already mentioned it in the previous section. This is your chance to learn how your peers work. Learn from it!

Better understanding of the code

By consistently reviewing your peers work, you'll learn what happens outside your zone. You'll get a complete view of the system you're working on, which will allow you to understand the affect of your code on all of the system.

Common goal

People tend to forget it. Your peer's success, is your organization's success which means your success! Help your peers improve their work, and your organization will become more successful, which you can only benefit from.

Let your voice be heard

How many times have you looked into others code and thought to yourself "what the hell they were thinking"? This is your time to prevent it! Let people know how you think things should be done. Not always will it work, but when it will, the future reader of the code (which might be you) will thank you for not letting things deteriorate.

What about the organization?

Organizations that encourage code-review will benefit greatly from the process. By creating more capable employees (which learn new-stuff all the time and improve their code-reading skills), by having a process the encourages knowledge-sharing. Also, new employees won't clutter the code due to their lack of understanding on how things work in the organization. The quality of the product will increase - allowing faster development of new feature and less bugs that the customers will have to face.

Lastly, code-review encourages discussion. An organization that wants to move forward should allow discussions and criticizing the process. Discussion is one of the most fruitful ways of taking the organization forward.

Hope I convinced you a bit more about code-review. In the next post I will cover the excuses I tend to hear as to why not to perform code-review. Stay tuned....

Find me on Twitter: @AviEtzioni

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Code Review - Just Do It! (Part 1 - Feedback)

I cannot over-estimate how important I think code-quality is. And yet, some people believe that code-review is not for them. Perhaps they think it takes too long, or they're too good for being reviewed by other team members.

Recently I gave a talk about the importance of the code review in my opinion. You can find it here:

For those of you who don't speak hebrew, or prefer to just read instead of watching the video, I'll try to summarize here. I split the lecture into 3 different posts, don't forget to follow up for the next posts.

Review - Not only for developers

I guess it wouldn't come to you as a complete surprise that review was not invented by or for the software engineering industry. Students at the university ask peers to review their work and sometime even pay good money for getting a professional review. Authors and journalist wouldn't dream of releasing their writings without them being reviewed by someone (usually more than one). And even this blog is reviewed by native English speakers to make sure I don't write in Hebrish (an un-understandable mixture of Hebrew and English).

How can that be that not all of the software-engineers think their work should be reviewed?

 Feedback is all around us

I have worked in agile methodologies for more than 3 years already. When we try to be agile we try to seek feedback in every step of the way in order to solve problems as soon as possible. In the "Lean Start Up" book, by Eric Ries, it's described as "The Feedback Loop".

 

During our work, we encounter a lot of feedback loops. I tried to map the main feedback loops on my work at Outbrain. I found 6 main feedback loops during a feature's development from when its requirements are passed from the PM to the development team and until it's released:

We start with writing a design, usually followed by a review and feedback from our peers. When we feel comfortable with the design, we start coding. And, while we code, the IDE warns us about errors in an extremely short feedback cycle. We then use automation tests to get feedback on whether we break the code, and when the code is committed it goes through a build process which provides us with a feedback on how our code is integrated in the system.

After the code is released, we have a great monitoring system in Outbrain to monitor the features affect (on the users or on the server load, or any other KPI). Lastly, when things go wrong, we conduct a take-in to make sure we learn from our mistakes.

Looking at all of those great feedbacks, we can group those into two groups. The first group would be "Automatic Feedback" and the second would be "Human Feedback" as described in this picture:

Interesting observations on these two groups would be that the "Automatic Feedback" group exposes symptoms, whereas the "Human Feedback" group exposes problems.

This actually means that we start our coding process by asking feedback, and only after we're done, and the feature's out, we try to learn from our mistakes. During the time between these two human interactions, we're pretty much on our own. Adding a code-review cycle gives us another opportunity to get human feedback and improve our code before it's committed/deployed.

In my next post, I'll try to convince you that code review is great for the reviewer, the reviewee and of course - the organization.

To be continued...

Find me on Twitter: @AviEtzioni

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