{"rowid": 304, "title": "Five Lessons From My First 18 Months as a Dev", "contents": "I recently moved from Sydney to London to start a dream job with Twitter as a software engineer. A software engineer! Who would have thought.\nHaving started my career as a journalist, the title \u2018engineer\u2019 is very strange to me. The notion of writing in first person is also very strange. Journalists are taught to be objective, invisible, to keep yourself out of the story. And here I am writing about myself on a public platform. Cringe.\nSince I started learning to code I\u2019ve often felt compelled to write about my experience. I want to share my excitement and struggles with the world! But as a junior I\u2019ve been held back by thoughts like \u2018whatever you have to say won\u2019t be technical enough\u2019, \u2018any time spent writing a blog would be better spent writing code\u2019, \u2018blogging is narcissistic\u2019, etc.\u00a0\nWell, I\u2019ve been told that your thirties are the years where you stop caring so much about what other people think. And I\u2019m almost 30. So here goes!\nThese are five key lessons from my first year and a half in tech:\nDeployments should delight, not dread \n\nLesson #1: Making your deployment process as simple as possible is worth the investment.\n\nIn my first dev job, I dreaded deployments. We would deploy every Sunday night at 8pm. Preparation would begin the Friday before. A nominated deployment manager would spend half a day tagging master, generating scripts, writing documentation and raising JIRAs. The only fun part was choosing a train gif to post in HipChat: \u2018All aboard! The deployment train leaves in 3, 2, 1\u2026\u201d\n\nWhen Sunday night came around, at least one person from every squad would need to be online to conduct smoke tests. Most times, the deployments would succeed. Other times they would fail. Regardless, deployments ate into people\u2019s weekend time\u200a\u2014\u200aand they were intense. Devs would rush to have their code approved before the Friday cutoff. Deployment managers who were new to the process would fear making a mistake.\u00a0\nThe team knew deployments were a problem. They were constantly striving to improve them. And what I\u2019ve learnt from Twitter is that when they do, their lives will be bliss.\nTweetDeck\u2019s deployment process fills me with joy and delight. It\u2019s quick, easy and stress free. In fact, it\u2019s so easy I deployed code on my first day in the job! Anyone can deploy, at any time of day, with a single command. Rollbacks are just as simple. There\u2019s no rush to make the deployment train. No manual preparation. No fuss. Value\u200a\u2014\u200awhether in the form of big new features, simple UI improvements or even production bug fixes\u200a\u2014\u200acan be shipped in an instant. The team assures me the process wasn\u2019t always like this. They invested lots of time in making their deployments better. And it\u2019s clearly paid off.\nCode reviews need love, time and acceptance \n\nLesson #2: Code reviews are a three-way gift. Every time I review someone else\u2019s code, I help them, the team and myself.\n\nCode reviews were another pain point in my previous job. And to be honest, I was part of the problem. I would raise code reviews that were far too big. They would take days, sometimes weeks, to get merged. One of my reviews had 96 comments! I would rarely review other people\u2019s code because I felt too junior, like my review didn\u2019t carry any weight.\u00a0\nThe review process itself was also tiring, and was often raised in retrospectives as being slow. In order for code to be merged it needed to have ticks of approval from two developers and a third tick from a peer tester. It was the responsibility of the author to assign the reviewers and tester. It was felt that if it was left to team members to assign themselves to reviews, the \u201csomeone else will do it\u201d mentality would kick in, and nothing would get done.\nAt TweetDeck, no-one is specifically assigned to reviews. Instead, when a review is raised, the entire team is notified. Without fail, someone will jump on it. Reviews are seen as blocking. They\u2019re seen to be equally, if not more important, than your own work. I haven\u2019t seen a review sit for longer than a few hours without comments.\u00a0\nWe also don\u2019t work on branches. We push single commits for review, which are then merged to master. This forces the team to work in small, incremental changes. If a review is too big, or if it\u2019s going to take up more than an hour of someone\u2019s time, it will be sent back.\nWhat I\u2019ve learnt so far at Twitter is that code reviews must be small. They must take priority. And they must be a team effort. Being a new starter is no \u201cget out of jail free card\u201d. In fact, it\u2019s even more of a reason to be reviewing code. Reviews are a great way to learn, get across the product and see different programming styles. If you\u2019re like me, and find code reviews daunting,  ask to pair with a senior until you feel more confident. I recently paired with my mentor at Twitter and found it really helpful.\nGet friendly with feature flagging \n\nLesson #3: Feature flagging gives you complete control over how you build and release a project.\n\nSay you\u2019re implementing a new feature. It\u2019s going to take a few weeks to complete. You\u2019ll complete the feature in small, incremental changes. At what point do these changes get merged to master? At what point do they get deployed? Do you start at the back end and finish with the UI, so the user won\u2019t see the changes until they\u2019re ready? With feature flagging\u200a\u2014\u200ait doesn\u2019t matter. In fact, with feature flagging, by the time you are ready to release your feature, it\u2019s already deployed, sitting happily in master with the rest of your codebase.\u00a0\nA feature flag is a boolean value that gets wrapped around the code relating to the thing you\u2019re working on. The code will only be executed if the value is true.\nif (TD.decider.get(\u2018new_feature\u2019)) {\n    //code for new feature goes here\n}\nIn my first dev job, I deployed a navigation link to the feature I\u2019d been working on, making it visible in the product, even though the feature wasn\u2019t ready. \u201cWhy didn\u2019t you use a feature flag?\u201d a senior dev asked me. An honest response would have been: \u201cBecause they\u2019re confusing to implement and I don\u2019t understand the benefits of using them.\u201d The fix had to wait until the next deployment.\nThe best thing about feature flagging at TweetDeck is that there is no need to deploy to turn on or off a feature. We set the status of the feature via an interface called Deckcider, and the code makes regular API requests to get the status.\u00a0\nAt TweetDeck we are also able to roll our features out progressively. The first rollout might be to a staging environment. Then to employees only. Then to 10 per cent of users, 20 per cent, 30 per cent, and so on. A gradual rollout allows you to monitor for bugs and unexpected behaviour, before releasing the feature to the entire user base.\nSometimes a piece of work requires changes to existing business logic. So the code might look more like this:\nif (TD.decider.get(\u2018change_to_existing_feature\u2019)) {\n    //new logic goes here\n} else {\n    //old logic goes here\n}\nThis seems messy, right? Riddling your code with if else statements to determine which path of logic should be executed, or which version of the UI should be displayed. But at Twitter, this is embraced. You can always clean up the code once a feature is turned on. This isn\u2019t essential, though. At least not in the early days. When a cheeky bug is discovered, having the flag in place allows the feature to be very quickly turned off again. \nLet data and experimentation drive development \n\nLesson #4: Use data to determine the direction of your product and measure its success.\n\nThe first company I worked for placed a huge amount of emphasis on data-driven decision making. If we had an idea, or if we wanted to make a change, we were encouraged to \u201cbring data\u201d to show why it was necessary. \u201cWithout data, you\u2019re just another person with an opinion,\u201d the chief data scientist would say. This attitude helped to ensure we were building the right things for our customers. Instead of just plucking a new feature out of thin air, it was chosen based on data that reflected its need.\nBut how do you design that feature? How do you know that the design you choose will have the desired impact? That\u2019s where experiments come into play.\u00a0\nAt TweetDeck we make UI changes that we hope will delight our users. But the assumptions we make about our users are often wrong. Our front-end team recently sat in a room and tried to guess which UIs from A/B tests had produced better results. Half the room guessed incorrectly every time.\nWe can\u2019t assume a change we want to make will have the impact we expect. So we run an experiment. Here\u2019s how it works. Users are placed into buckets. One bucket of users will have access to the new feature, the other won\u2019t. We hypothesise that the bucket exposed to the new feature will have better results. The beauty of running an experiment is that we\u2019ll know for sure. Instead of blindly releasing the feature to all users without knowing its impact, once the experiment has run its course, we\u2019ll have the data to make decisions accordingly.\nHire the developer, not the degree\n\nLesson #5: Testing candidates on real world problems will allow applicants from all backgrounds to shine.\n\nSurely, a company like Twitter would give their applicants insanely difficult code tests, and the toughest technical questions, that only the cleverest CS graduates could pass, I told myself when applying for the job. Lucky for me, this wasn\u2019t the case. The process was insanely difficult\u2014don\u2019t get me wrong\u2014but the team at TweetDeck gave me real world problems to solve.\nThe first code test involved bug fixes, performance and testing. The second involved DOM traversal and manipulation. Instead of being put on the spot in a room with a whiteboard and pen I was given a task, access to the internet, and time to work on it. Similarly, in my technical interviews, I was asked to pair program on real world problems that I was likely to face on the job.\nIn one of my phone screenings I was told Twitter wanted to increase diversity in its teams. Not just gender diversity, but also diversity of experience and background. Six months later, with a bunch of new hires, team lead Tom Ashworth says TweetDeck has the most diverse team it\u2019s ever had. \u201cWe designed an interview process that gave us a way to simulate the actual job,\u201d he said. \u201cIt\u2019s not about testing whether you learnt an algorithm in school.\u201d\nIs this lowering the bar? No. The bar is whether a candidate has the ability to solve problems they are likely to face on the job. I recently spoke to a longstanding Atlassian engineer who said they hadn\u2019t seen an algorithm in their seven years at the company.\nThese days, only about 50 per cent of developers have computer science degrees. The majority of developers are self taught, learn on the job or via online courses. If you want to increase diversity in your engineering team, ensure your interview process isn\u2019t excluding these people.", "year": "2016", "author": "Amy Simmons", "author_slug": "amysimmons", "published": "2016-12-20T00:00:00+00:00", "url": "https://24ways.org/2016/my-first-18-months-as-a-dev/", "topic": "process"}