When we add new components or make changes, we update the gem (as well as the docs site associated with Style Closet) and simply release the new version. Below is a test written in Groovy, which sets up fixture data that mimics the exact situation in our Meet Joe example. Or they can define some SLOs around types of on-call tasks that their team tackles each week. I applied online. Complete a pair programming exercise consisting of some starter code and finishing out a key function. The product and engineering leadership I spoke to all came off as humble and knowledgeable, and were open about existing pain points and challenges. Last fall, Betterment optimized its portfolio, moving from the original platform to an upgraded trading platform that included more asset classes and the ability to weight exposure of each asset class differently for every level of risk. We originally ran our data platform on a single machine in 2015 when we ingested far less data with fewer consumer-facing requirements. Tell me about yourself. However, a user transaction object contains a host of data that isnt relevant to the trades that will eventually be created, and is associated with other objects that are also not relevant. 25 Citrus Informatics Engineering - Software & QA Department Reviews by current and past employees about salary & benefits work culture skill development career growth job security work-life balance and more. Engineering at Betterment: Do You Have to Be a Financial Expert? Transitioning from Luigi toAirflow Our single-server approach usedLuigi, a Python module created to orchestrate long-running batch jobs with dependencies. Check out more error budget math here. We included realistic dividends at an asset class level. Not to mention almost everything else I needed I was able to learn through Google, which makes me wonder if I could have learned Java through the Internet in a few weeks rather than spending the past two years in school? Ask-me-anything1:1 with an engineer on another team, 3. Here Id like to discuss some philosophical approaches to defining SLOs, explain how they help with prioritization, and outline the tooling currently available to Betterment Engineers to make this process a little easier. If you had prior experience with these languages the problems are easy to solve. I thought my 5 year was going to finally show something but it did not. Instead of four analysts all inventing their own method for loading and cleaning a table of users, you can share as a group the utils/LoadUsers() function and ensure you are talking about the same people at every meeting. Phone screen is super basic, technical wasn't hard, but you need to solve the problem at hand. Since one of the draws of using Julia in the first place is the performance of the code, we make sure to benchmark our code during every pull request for potential performance regressions using theBenchmarkTools.jlpackage. The culture of learning. We use a multi-threaded web server for our production application, and so when we make a call into the Julia shared library, we push that call onto a queue where it gets picked up and performed by a single executor thread which then communicates the result back to the calling thread using apromiseobject. On the way out, GSON would re-inflate the JSON back into Java objects, using dummy values for the irrelevant fields, providing us with test inputs ready to be pushed through our system. If there was an issue, how did you handle the situation? Maybe their on-call is really busy, maybe there are a lot of manual interventions needed to keep their services running, maybe theyre still putting out fires and building out their teams systems. To be more concrete about this, lets define some variables. The contract defines the expectations of input and output for the exchange. This question can help the interviewer understand how you approach a project and what your thought process is. Dealing With the Uncertainty of Legacy Code To complete our portfolio optimization, we had to tackle a lot of legacy code. Some of these are: Secrets are unguessableShort strings like password are not really secrets and this check enforces strings that are at least 128 bits of entropy expressed in unpadded base64. We wanted to highlight metrics such as net deposits, assets under management, and conversions from visitors to the site into Betterment customers. I moved to Nashville to study songwriting and music business, and started a small label through which I released my bands album. For us, that meant having clear, readable tests that were a joy to write. For this reason, we chose to wrapLABiometryTypebehind our ownBiometryTypeenum. As a corollary to Rule #1, we should ensure that all authorization happens in the controller by disallowing model initialization with *_id attributes. Instead of multiple interviewers asking a candidate about the same questions based on their resum, we prescribe topics based on the most important core competencies of successful (Betterment) engineers. What genre of music do you listen to when youre coding? What all of these tasks had in common (aside from being, well, really important to our business) is that they were executed via a database-backed job-execution framework called Delayed, a newly-open-sourced library that were excited to announce right now, as part of this blog post! When we make improvements to one project types base configuration, we can flip a switch and turn it on foreveryone in the org at once. At the time, our application had no established patterns or tooling for the kinds of third-party integrations that customers were increasingly expecting from fintech products (e.g., like how Venmo connects to your bank to directly deposit and withdraw money). assuming a secret-editor role The sops command will open and decrypt the secrets in their editor and, if changed, encrypt them and save them back to the files original location. In this post, well dive into some of the engineering that took place to build RetireGuide and our strategy for building an accurate, responsive, and easy-to-use advice tool that implements sophisticated financial calculations. We came up with a few rules to design this part of the system: Let the author knowas soon as possiblewhen something is red but dont overdo it for redundant failures within the same job (e.g. Define our process For us the obvious first order of business was to deliver continuous, incremental value and gradual transition from legacy systems to new ones. At the time, we also couldnt find a way to federate permissions with Ansible Vault in a way that didnt hinder our workflow by causing a bottleneck for developers. Not only was this frustrating, but it was inefficient. Then we do the same for the deposit API call. In planning out integration testing, we had a few key requirements for our integration testing suite: Easily runnable in CI upon each commit An API that would be familiar to developers who are used to writing flutter screen tests The ability to test the integration between features within the system without needing to set up the entire app. Anonymous Interview Candidate in New York, NY, The process took 1 week. Not only does this increase test readability (each set up method will set up only the dependencies needed for the tests below it and within the same scope in the testing tree), but this reduces the scope for potential problems. Well dive more into system spec best practices in a future blog post. 0<=a1<=5 0<=a2<=1 0<=a3<=3 0<=a4<=6 0<=d7<=1 That expresses all of the constraints and bounds to our problem and the optimizer works to maximize or minimize the objective function subject to those bounds and constraints. As a Rails shop, we already make heavy use of RuboCop. What are "end-to-end-ish" tests? Say that we want to start by testing the profile edit flow. Using UJS patterns, our view can live completely on the server. One Massive Monte Carlo, One Very Efficient Solution We optimized our portfolio management algorithms in six hours for less than $500. Think of something like Heroku, but for engineers here at Betterment. You will need to be passingly familiar with the language they're using. I made the jump to start becoming an engineer. First was with 2 members on the team, last was with a manager. What is legacy code? Its how we work every day. Below is a table summarizing Joes holdings: Account Type: VTI (U.S. Total Market) VWOB (Emerging Markets Bonds) Account Total Taxable $5,500 $5,500 $11,000 Roth $2,750 $2,750 $5,500 Asset Class Total $8,250 $8,250 $16,500 To begin to construct our model for an optimal asset location strategy, we need to consider the relative value of each fund in both accounts. So well need to consider carefully! Tax efficiency is a key consideration of Betterments portfolio management philosophy. Interactive elements, some delightful animations, and other frontend behaviors still need it. Asking questions, definitely. Putting it alltogether Our configuration generator is doing a lot more than just taping together jobs in a workflowwe evaluate dependency graphs and only run certain jobs that have upstream changes or are triggered themselves. To learn more about engineering at Betterment, visit the engineering page on the Betterment Resource Center. Keep in mind, descriptive group names go a long way in adding clarity to what dependencies that bucket relies upon. We think this tool works well with the way we think about secrets management. Byteboard. We repeated multiple styles and page elements throughout the app to make the experience consistent, but we didnt have a great way to reuse the common elements. You'll also practice critically evaluating your own code, and you'll build technical communication skills that will help you prepare for job interviews and collaborative work as a software engineer. CPU optimized) to further reduce costs. Continuous Delivery (CD) at scale is hard to get right. Not even knowing we didn't do it very bad. These were our outputs. All it took was 1 week. When reviewing code, I look for adherence to coding standards, code efficiency, readability, and maintainability. Its a really exciting time to be a software engineer, especially in fintech. I am passionate about making a positive impact on society through the construction of safe . The circles represent various asset classes, and the bar shows the allocation for all the accounts, if added together. - Final interview, stay on one project, swap groups of different interviewers. The most obvious alternative was a computer, but then many of our engineers expressed concerns with this method, having had bad experiences with computer-based interviews in the past. Relevant ecosystem. And this bounty of information helps a lot if the engineer has multiple PRs open and needs to quickly switch context. Maintaining a Data Dictionary wiki became a part of our Definition of Done. Do error rates for this particular endpoint directly reflect an experience of a user in some way - be it a customer, a customer-facing API, or a Betterment engineer? They were honest and straight shooter, got a good sense of the mainly good and bad working at Betterment. Too tough to call. Taking the time to understand the code and write tests before refactoring will save you headaches in the future. First there was an online assessment by ByteBoard. The CLI handles notifications, artifact generation, and deployment triggers. I was able to build my dashboards as a Web app, so I not only needed to understand this structure, but I needed to implement it as well. The last part of defining our SLOs is including a date when we plan to revisit that SLO specification. To implement this pattern, we use AmazonS3as a persistent storage tier. Betterment interview details: 102 interview questions and 87 interview reviews posted anonymously by Betterment interview candidates. I did not get the offer but I would have declined as I was offered a position from two other companies. I couldnt tell you what a dividend was. For more information about working at Betterment, please visit our Careers page. In doing all of these things, weve reduced bottlenecks for developers so they can focus more on shipping features and less on managing secrets. But we do believe strongly that theres more to agree about than our industry has been able to establish so far. Some examples: html_safe: [1] pry(main)> include ActionView::Helpers::OutputSafetyHelper => Object [2] pry(main)> result = hi.html_safe => hi [3] pry(main)> result.class => ActiveSupport::SafeBuffer raw: [1] pry(main)> result = raw(hi) => hi [2] pry(main)> result.class => ActiveSupport::SafeBuffer safe_concat: [1] pry(main)> include ActionView::Helpers::TextHelper => Object [2] pry(main)> buffer1 = hi.html_safe => hi [3] pry(main)> result = buffer1.safe_concat(bye) => hibye [4] pry(main)> result.class => ActiveSupport::SafeBuffer safe_join: [1] pry(main)> include ActionView::Helpers::OutputSafetyHelper => Object [2] pry(main)> result = safe_join([hi, bye]) =>
hi
bye
[3] pry(main)> result.class => ActiveSupport::SafeBuffer => ActiveSupport::SafeBuffer Rubocop: weresafe! Technical problems really felt more like they were grounded more in learning your thought process and general development style. chicken:6.000lbs(6.0instock) carrots:0.667lbs(8.0instock) thyme:0.183lbs(19.0instock) onions:0.733lbs(12.0instock) noodles:0.000lbs(0.0instock) garlic:0.000lbs(1.0instock) parsley:0.000lbs(6.0instock) 13.956lbsoffoodfromJerry's. Striving for Simplicity At Betterment, we aim to build products that help our customers reach their financial goals. We still have our route, controller, and model, but instead of a jbuilder for returning JSON, we can port our template to embedded Ruby, and let the server do all the work. The problem with this is that whenraworhtmlsafeare used to mark content as already safe by putting it in aSafeBufferas is,safejoinwill not actually do anything additional to escape the content. Instead, each worker acts independently. For these things, we are using HTMLdata elements to specify behaviors. You can also watch myRails at Scale talkto learn why we developed them and how we maintain them. Im going to take you through our testing journey from a limited native automated testing suite and heavy dependence on manual testing, to trying flutters integration testing solutions, to ultimately deciding to build out our own framework to increase confidence in the integration of our components. Normally wed consider opting out of security analysis to be an unsafe thing to do, but we actually like the way RuboCop handles this because it can help reduce some code review effort; the first solution eliminates the vulnerable-looking pattern (even if it wasnt a vulnerability to begin with) while the second one signals to reviewers that they should confirm this code is actually safe (making it easy to pinpoint areas of focus). (For the record, they stand for The Depository Trust Company, Committee on Uniform Security Identification Procedures, and Automated Customer Account Transfer Service, respectively.) We did it! Innovative problem solving. Then, we configure our init system, upstart, to execute the process wrapped in the sopsorific run command. Those interviewers dont fill out a scorecard, and our hiring managers are forbidden from discussing candidates with them. Variable server response times do not provide an optimal user experience, especially when performing personalized financial projections. Meetings thus far have included a panel discussion on breaking into tech from the corporate world and a small-group financial discussion led by financial experts from Betterment and beyond. Such linked websites are not monitored, investigated, or checked for accuracy or completeness by Betterment. Our Principles in Action: Shortening the FeedbackLoop The feedback loop in the Old World run by Jenkins was one of the biggest hurdles to overcome. We liked notifying engineers when a deploy began, but we needed to be more accurate about who we were notifying. Instead of multiple interviewers asking a candidate about the same questions based on their resum, we prescribe topics based on the most important core competencies of successful (Betterment) engineers. In the end, we want to verify the plumbing of user input and business logic output through as few large specs per feature that we can get away with. Server JavaScript: A Single-Page App ToA Single-Page App Betterment engineers recently migrated a single-page backbone app to a server-driven Rails experience. Not quite. Depends on my feelings about the problem I'm working on. Build a killer testing framework When dealing with legacy code, one of our top priorities is to preserve existing functionality. Abletocarry15.0pounds. Keep in mind, this was an opportunity unlike any other I had up to this point in my life, but once I got to talking with the interviewers, the conversation just flowed. High quality code. We usedRails partialsin an effort to keep the code DRY (Dont Repeat Yourself) while sharing the same chunks of code and that got us pretty far, but it had its limitations. Glassdoor has millions of jobs plus salary information, company reviews, and interview questions from people on the inside making it easy to find a job thats right for you. What areas are you looking to grow in? We dont expect these principles to appeal to everybody. All the new features were working on for customers with multiple accountsbe they Individual Retirement Accounts (IRAs), taxable investment accounts, trusts, joint accounts, or even synced outside accountsrequired this change. Testing our Rails applications allows us to build features more quickly and confidently by proving that code does what we think it should, catching regression bugs, and serving as documentation for our code. Sometimes, it's a good idea to think outside the box in order to strike the right balance of test coverage, confidence, and maintainability. One year later, weve asked them to reflect on their experiences. Relieving Launch Day Stress with Feature Flags Embarking on this rebrand project, we wanted to keep our designs under wrap until launch day. Making a fake implementation of that plugin is typically as easy as making another class, prefixing its name with Fake and having it implement the public contract of the regular plugin class with suitably real but not quite real behavior. The Soup Nazi should only buy a total of 40 lbs worth ingredients because Elaine, George, Jerry, and Newman just dont have enough chicken. We talked about my career and what I was looking for. When I started working at Betterment, I barely knew anything about finance. It's just collecting fake responses and organizing them so that they're easy to access later.As you can see, the internals are pretty tiny. Google question - Design an access card system. If we need to change our brand colors, lets say, we can just change the CSS in Style Closet instead of scraping our codebase and making sure we catch it everywhere. This allows us to encapsulate both the need to use an iOS 11 compiler flag and the need to callcanEvaluatePolicy(_:error:)on an instance ofLAContextbefore accessing itsbiometryTypeproperty into a single calculated property: See the Gist. Working closely with Product, Design, Marketing, and Research, we brainstorm, ideate, build, and push our thinking and perspectives. For this problem, we made our initial guess to be what each store had in stock, and we supplied it to the minimize method as a list. What did we need? With VisiCalc, the first-ever spreadsheet program, in 1979 and Excel in 1987, the business world stepped into two new eras in which any employee could manage large amounts of data. Takeaways Testing software is important, but it's not trivial to write a balanced test suite for your app's needs. This is a rails specific interview, where you get a rails app and you go through it fixing and creating features. Now, our work involved dispelling our previous understanding of what a name is. Flutter provides good solutions for both screen testing and UI testing, but what about the middle-ground? First was with 2 members on the team, last was with a manager. Personal finance is not something many college students think aboutpartially because its not taught in school and partially because we dont have any money to worry about anyway. Betterment is an engineering-driven company that has developed the most trusted online financial advisor based on the principles of optimization and efficiency. I was shocked! Do no harm to others' work At Betterment, we are constantly pushing through new features and enhancements, some visible to customers, but many not. Besides the performance benefits, reading a single system spec from beginning to end ends up being good high-level documentation of how the software is used. We then pivoted to investigating Flutters newer replacement for flutter_driver: integation_test. We wrote a controller-level hook to update the variant and render the new layout files, reskinning thepackage. As developers of financial software on the web, one of our biggest responsibilities is to keep our applications secure. If we do this right, we will be able to swap everything to a normal Rails app with minimal effort. Using the JavaScript single page app framework, we would need a few things. 1. You never know when youll want to circle back. Before we dive into how we built it, lets revisit our requirements from above: Easily runnable in CI upon each commit An API that would be familiar to developers who are used to writing flutter screen tests The ability to test the integration between features within the system without needing to set up the entire app. We were also required to rename several core concepts, and make some big changes to the way we display data to our customers. Shh Its a Secret: Managing Secrets at Betterment Opinionated secrets management that helps us sleep at night. Anything that didnt get a new, rebranded template stayed in the world of plain old production. Technical interview (computer science fundamentals), Technical interview (modelling and app design), Ask the candidate to describe a recent technical challenge in detail, Introduce the pair programming problem and explore the problem, Pair programming (optional, time permitting). Companies should strive for a fair balance between adding new features and refactoring legacy code, and should establish a culture where thoughtful code design is a priority. Cleaning up the most looked at metrics helped the organization speak to and understand key data in a consistent manner. Opens the Fishbowl by Glassdoor site in a new window. This simple question from our trans customers Can you quit deadnaming me? was a sign that our original understanding of our customers' names was not quite right, and we were lacking knowledge around how names are commonly used. If our SLOs dont align directly with business objectives and needs, they should align indirectly via tracking operational complexity and maturity. You want to help others whenever you can; and it has been the case that Ive received plenty of help from others who arent even directly on my team. Though our contract with projects of different types is standardized, we permit some level of customization. The last of our requirements was to be able to launch into a specific feature rather than having to navigate through the whole app. Its our job to fine-tune these to help our clients, and its very important we have these decisions be robust to the widest possible array of potential futures they might face. By doing this piecemeal, we are hoping to bake in useful patterns early on, which we can iterate and use to make migrating the next part even simpler. Engineers' productivity and happiness decrease as even the smallest tasks can be frustrating and time-consuming. @Sla @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.METHOD) public @interface Sla { @AliasFor(annotation = Sla.class) long amount() default 25_000; @AliasFor(annotation = Sla.class) ChronoUnit unit() default ChronoUnit.MILLIS; @AliasFor(annotation = Sla.class) String service() default "custody-web"; @AliasFor(annotation = Sla.class) String slackChannelName() default "java-team-alerts"; @AliasFor(annotation = Sla.class) boolean shouldPage() default false; @AliasFor(annotation = Sla.class) String owner() default "java-team"; } Then usage is just as simple as adding the annotation to the controller: @WebController("/api/stuff/v1/service_we_care_about") public class ServiceWeCareAboutController { @PostMapping("/search") @CustodySla(amount = 500) public SearchResponse search(@RequestBody @Valid SearchRequest request) {} } At deploy time, these annotations are scanned and converted into monitors along with the config-driven definitions, just like our Ruby implementation. One tech phone screen, 5 hrs on site with other team leads, hiring manager, CTO, and a follow-up 2hrs onsite tech interview, offer was made. Try it out! We still lacked a good way to share markup across all our apps. 3 step process for me: Junior Software Engineer interview questions play a vital role in the job search process. Accessing the database requires knowledge of SQL, a lot of scripts are written in Python, front end structure and design is written in HTML and CSS, and front end animation is written in javascript. You should follow GitLab's example and make Ruby a requirement if you're going to continue your practice of having an onsite where Ruby is the only allowed language. In the case of service level indicators (basically metrics collection), the Coach CLI provides commands that generate yaml files to be stored in GitHub alongside application code. - Final interview, stay on one project, swap groups of different interviewers. Focusing on What Matters: Using SLOs to Pursue User Happiness Proper reliability is the greatest operational requirement for any service. Following the above tips should put you well on your way to fixing existing problems in your test suite or otherwise preventing them all together! (a1+b1+c1+d1)(.40*totalpounds)>0 (a7+b7+c7+d7)(.05*totalpounds)>0 Note here that I changed the constraints from equal-to to greater-than because comparing floats to be exactly equal is a hard problem when youre multiplying and adding numbers. By partnering with Peoplism and building a long-term, action-oriented plan, were working to create real change in a sustainable fashion. One next step were excited about is an examination of our mentorship program to make sure that everyone at Betterment has access to mentors. Julia has excellent support for technical computing and mathematical modelling. Betterment is one of them. This approach puts candidates at ease, and feels closer to typical pair programming than one might expect. The input data was serialized and automatically fed back into our test fixtures. They are very specific, testing a small portion of the system (the model under test), and cover a wide range of corner cases in that area. Take a minute and review this controller - what jumps out to you? But in addition to the resiliency guarantees outlined above, weve also given a lot of attention to the operability and the scalability of our queue. Lets start out by exploring that robot testing technique I mentioned earlier. Our custom solution to integration testing After trying flutters solutions fruitlessly, we decided to build out a solution of our own. For Betterment engineers, it meant restructuring the underlying portfolio data model for increased flexibility. We valued sending Slack messages to our engineers, as thats how the company communicates most effectively, but we didnt like the rate of communication or the content of those messages. These tests are as close to end-to-end tests as we can get without actually running on a real device using flutter_driver. While speed of execution is important, we also require a dynamic language that allows us to test out new ideas and prototype rapidly. The calculator focuses on just one part of the broader set of retirement calculations, and doesnt have the functionality to automatically import customers existing information. Menu . The Nitty Gritty Details In order to describe how our integration tests work, let's start by describing an example app that we may want to test. The benefit we found in flutter_driver was that we could run it in our production-like environment against preset test users. Questions Interviews are now more prescriptive regarding non-technical questions. Below is an example of one of our components, the flash. Lets plug in some balances to see what the expected value of V is with Joes current holdings: V=0.07*5500+0.04*5500+0.06*2750+0.05*2750=907.5 Certainly, we can do better. Being able to integrate (ba dum tss) these new tests into our existing test suite is excellent because it meant that we would get quick feedback when code breaks while developing. It doesnt take a very large business these days to collect more than 1 million observations of customer interactions or transactions. In fact, sometimes it was hard to even know where to start to make changes. We built ourCoach CLIinto the Docker images we use in CircleCI and so those Coach CLI commands are available to us from inside the.circleci/config.ymlfile.