TL;DRWebValve is an open-source gem that uses Sinatra and WebMock to provide fake HTTP service behavior. As weve circled back to clean up these lower-traffic views and give them the full rebrand treatment, weve come closer to deleting the opt_out CSS manifest and deprecating our our legacy stylesheets for good. Keeping Our Code Base Simple, Optimally Betterment engineers turned regulatory compliance rules into an optimization problem to keep the code base simple. They say multiple times that you can come into this job not knowing any rails, and that the interviewers will be accommodating of your background, this is a quarter true. It's better to ask a question and move forward with your problem than it is to struggle over an answer. Software engineering jobs tend to fall under two categories: domain-specific or general programming. It starts with our users - Betterment users - and trying to provide them with a certain quality of service. Tooling To simplify development, we use a lot of tooling and infrastructure developed both in-house and by the Julia community. Here's what our API looks like and how we use it to set up a fake HTTP client for our tests. Implementing the Rebrand without a Spaghetti of IF Statements Our rebranded experience would become the default at launch time, so another challenge we faced was maintaining two worlds without creating unneeded complexity. Betterments engineers decided, therefore, that it was critical to our mission that we be capable of handling each and every contract as reliably as possible. Note that the contribution limits mentioned in this example are as of the time this article was published. Tests were flakey and we didnt know if it was our Jenkins setup, the tests themselves, or both. Working closely with Product, Design, Marketing, and Research, we brainstorm, ideate, build, and push our thinking and perspectives. However, there are still a few more things to note: Get numpy and scipy installed. If you remember nothing else, remember this. We decided to allow candidates the choice of using a whiteboard if they wished, but it would no longer be the default method for presenting ones skills. What inspired you to become a civil engineer? Too often, the events involved forced networking and stodgy PowerPoint presentations, with takeaways amounting to little more than a free glass of wine. Heres how we did it. Ship It Our first run of this new process took place in November 2015. In this example, we want to maximize the expected value of the holdings in Joes accounts. We stay in regular contact with stakeholders throughout a build-out and iterate over MVPs. To learn more about engineering at Betterment, visit the engineering page on the Betterment Resource Center. 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. After flipping the feature flag and establishing rebrand as the permanent variant context, all that remained was to destroy the legacy files that were no longer being rendered and remove the variant name from the file extension of the new primary view template. As an added bonus, since our CI process itself was defined in code, if we ever need to switch platforms again, it would be much easier. Instead, we stored them in a flat SQLite database. We might take a look at the metrics were using (the SLIs), the failures that chipped away at our target goal, and, if necessary, re-evaluate the relevancy of what were measuring. -> % coach create project --type ruby_app 'coach.yml' configuration file added -- update it based on your project's needs When you run that, the CLI creates the smallcoach.ymlconfiguration definition file discussed earlier. The process took 3 weeks. 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. You want to allocate your bonus proportionally in the same way you allocate your regular paychecks. No existing library allows us to integrate this way and map HTTP requests to in-process fakes for integration and development. She and I have been talking with each other at events and conferences and meetups (and even just online) almost weekly since then about getting more girls into tech, working, and everything in between. Enqueues and Transactions See, theres a major gotcha that may not be obvious from the list of ActiveJob backends. You can find these cops here. This allows the view to be reusable. Given requirements, explain how one may model some data. Second, flutter_driver is more about UI/E2E testing rather than integration testing, meaning wed need to run an instance of the app on a device, navigate to a flow we wanted to test, and then test the flow. This leaves our app looking something like this: Given that this is approximately what the app looks like, the test harness needs to grant control of the HttpClient and the ImageCropperService. Working with Betterments applications gave me a hands-on understanding of concepts that are hard to reproduce on a smaller, personal application level. Think critically about what each type of spec is intended to be doing while writing specs. While we didnt run a scientifically valid split-test for the new process versus the old (it wouldve taken years to reach statistical significance), our hiring metrics have improved across the board. Continuous IntegrationOur Principles For years, we usedJenkins, an open-source tool for automation, and a mess of scripts to provide CI/CD to our engineers. Make sure that the bulk of the logic youre testing in a model spec is in the method youre exercising (unless the underlying methods are private). Read our blog post to find out more. Failure to do so could mean anything from creating a minor inconvenience to blocking trades from executing. Any insights would be helpful. Before I began my internship, I had never worked on a Web app before. We think engineers should focus on what they care about the most, shipping great features quickly and reliably. How is their IT department for roles like Director or VP? Option 2: Port the R Code to JavaScript Because our Web application already makes extensive use of JavaScript, another option was to implement our R financial models in JavaScript and run all calculations client-side, on the end users Web browser. There are a few other advantages and problems this system solves too: Were able to make global changes in a pretty painless way. Similarly, weve also done this for emerging markets bonds. Our variant also required a new CSS file, where all our new styles would live. 12.0availableacrossallstores. One of these things was having an opinionated tool to help us manage secrets helped to make sure we didnt accidentally leave around low-entropy secrets from when we were developing or testing out a feature. The one additional advantage of integration_test is that it uses the same API as screen tests do, so writing tests with it feels more familiar for developers experienced with writing screen tests. Heavy mocking can make tests harder to read, harder to maintain, and provide less assurance that code is working as expected. Dell question - Implement a distributed lock for large-scale cluster. This brought up another problem (and the starting point for this blog post): in order to ensure tight feedback loops, we strongly believed that our devs should be able to do their work on a modern, modestly-specced laptop without internet connectivity. First, lets take a look at the underlying framework we use for enqueuing and executing said jobs. 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. Sopsorific, also written in Go, makes a few assumptions about application environments. Easy and comprehensive testing. These arent necessarily true-to-form SLOs but engineers can use this framework and tooling provided to collect data around how their systems are operating and have conversations on prioritization based on what they discover, beginning to build a culture of observability and accountability Conclusion Betterment is at a point in its growth where prioritization has become more difficult and more important. Its exciting to see how Ive developed since I first started attending meetups, and how some of our long-time attendees have grown as engineers and as professionals. Building A Community Of Our Own In 2018, our Women of Betterment group had an idea. Sometimes, it's a good idea to think outside the box in order to strike the right balance of test coverage, confidence, and maintainability. When requested through the Local Authentication framework, the biometry evaluation either succeeds or fails separate from any given state of an application. You are viewing a web property located at Betterment.com. What kind of monitoring would be necessary to detect such a failure, across all the features of our app, and all the types of jobs it might try to run? Weve been doing CD at Betterment for a long time, but it had grown to be quite a cumbersome process over the last few years because our infrastructure and tools hadnt evolved to meet the needs of our growing engineering team. They look just like widget tests (because they are just widget tests) but they boot up our whole app, run all the real initialization code, and rely on all our real injected dependencies with a few key exceptions (more on that next). We have a strong preference to use a single integration pattern for both internal and external service integrations; this reduces cognitive overhead for devs. Find contacts: direct phone number, email address, work experience. This is such a minor change, in fact, that we were able to reuse all of our same view controllers that we had built for Touch ID with only a handful of string values that are now determined at runtime. The focus of our work has been on delivering a platform as a service to make sense of the complex process of CD. We chose to fake the http client since it is the very edge of our network layer. The main exception to these guidelines is when your controller is an API controller serving data to another app. What does the future hold? A number of factors are used to determine this, but most importantly each funds tax efficiency and expected returns. It isnt that much of a stretch to claim that an engineers level of happiness does have some effect on the level of service theyre capable of providing a Betterment customer! This looks very similar to a Sinatra app, and that's because it is onewith some additional magic baked in. Finally, we will share some tactics for enabling data scientists to be more collaborative and presentational with their R or Python visualizations. Lets say weve defined some SLOs and notice they are falling behind over time. Every component is on brand and consistent with every other app, feels polished, high quality and requires lower effort to implement. Phone call + take home test prior to onsite. The content on this page is reflective of a specific point in time (as of the publication date). 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. 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). She and I started emailing and video chatting each other during my senior year of college, when I started working with her on the Big Dream Documentary and the International Womens Hackathon at the USA Science and Engineering Festival. (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. Our hiring managers now report that they have a much clearer understanding of what each candidate brings to the table. While running R server-side is a win on code-reuse, its a loss on scalability and user experience. Kelly Hoey - I met Kelly at a women in tech hackathon during my last summer as a student in 2013, and then she ended up being on my team on the British Airways UnGrounded Thinking hackathon. Betterment interview details: 102 interview questions and 87 interview reviews posted anonymously by Betterment interview candidates. In practice, that might look something like this: Resulting in a function for which the fact that the underlying implementation is in Julia has been completely abstracted away: Challenges & Pitfalls Debugging an FFI integration can be challenging; any misconfiguration is likely to result in the dreadedsegmentation faultthe cause of which can be difficult to hunt down. While there was a lot of work involved in making our actual implementation production-ready (and a lot more work can be done to improve it), being able to express rules coming out of a regulatory document as a series of bounds and constraints via anonymous functions was a win for the readability of our code base. If youre writing tests for your Flutter application, its safe to assume that your goal is to build a robust, reliable piece of software that you can be confident in. The way the final interview was setup made me rave about it to pretty much everyone I knew. This can be accomplished by establishing a secure session on the server and running what you would normally run to get a console with the sopsorific run command. The tools to get us there Lets dive into some tooling that the SRE team at Betterment has built to help Betterment engineers easily start to measure things. Were running Airflows database on AmazonsRelational Database Serviceand using AmazonsElasticachefor Redis queuing. Dozens of engineers contribute to our biggest repository every day and as the code base and engineering team have grown, the complexity of our CI story has increased and our existing pipeline couldnt keep up. Further, because all three schemas live in the same MySQL server, client_analytics becomes a central hub from which our colleagues can join tables that have not yet been modeled in the warehouse with key dimensions that have been. I have experience in several different backend/ frontend frameworks, yet rails has some specific quirks, and your interviewers will not help you in this regard, but will simply try to see how you figure out, so they basically force you to google mid interview, and set you on a timer. But we do believe strongly that theres more to agree about than our industry has been able to establish so far. To do this, we can relate the terms with the terms using linear constraints. But we saw that the right building blocks existed to do what we wanted and proceeded with the confidence that it was theoretically possible. When I started working at Betterment, I barely knew anything about finance. These tests are as close to end-to-end tests as we can get without actually running on a real device using flutter_driver. R and Python both have great tools to produce finished reports as static HTML or PDF documents, or even interactive reporting and visualization products. We wrote a controller-level hook to update the variant and render the new layout files, reskinning thepackage. False Positives With any type of static analysis, theres bound to be false positives. 2 hr ByteBoard interview - 40 min design and algorithms (know your standard data structures and algorithms), 70 mins implementing some methods We left this outside of application code so that teams can modify SLO target goals and details without having to redeploy the application itself. IMHO, Betterment hiring process is best in the business. We believe in a world where shipping code, even in really large codebases with lots of contributors, should be done dozens of times a day. . In the final Capstone Project, you'll apply your skills to analyze data collected from a real-world (social) network. How it works now Now that we knowwhocan do what, lets talk abouthow they can do what they can do. While speed of execution is important, we also require a dynamic language that allows us to test out new ideas and prototype rapidly. On Fishbowl, you can share insights and advice anonymously with Betterment employees and get real answers from people on the inside. Engineers never really knew where their code was in the pipeline. If content is inside aSafeBuffer, Rails wont try to escape it upon rendering. Then, we configure our init system, upstart, to execute the process wrapped in the sopsorific run command. My assignment was to give everyone in the office a visual snapshot of how the company is doing. With our new Tax Coordination feature, were continuing the mission to help our customers portfolios become as tax efficient as possible. He did a good job explaining the different roles available and listening to my needs without being too pushy. This may seem less important inside a corporate bubble where everyone has access to the same proprietary platform, but it is at the very least a turnoff to most new talent in the field. Pact's docs encourage these human conversations, but as a tool it doesn't require them. And this is precisely why, at Betterment, we start each application off with a database-backed queue, co-located with the rest of the apps data, with the guarantee of at-least-once job execution. From an applications perspective, this relationship between a biometric scanner and the Secure Enclave is simplified to a boolean response. Our final allocations are therefore [38271, 43210, 24691, 17284]. Secondly, its missing environment-specific behavior, which in this case, translates into the ability to toggle the library on and off and separately toggle the connection to specific collaborator services on and off. Once we solve this very solvable idempotency problem, then were on track for the same net result as an exactly-once approach, even if it takes a couple extra attempts to get there. Multiply the inflow (or the payout in the example above) by each weight (where the weights are the integer amounts of the buckets, so the contributions to the ticket in our example above), and divide each of these products by the sum of the buckets, finding the integer quotient and integer remainder Find the number of pennies that will be left over to allocate by taking the inflow minus the total of the integer quotients Sort the remainders in descending order and allocate any leftover pennies to the buckets in this order The idea here is that the quotients represent the amounts we should give each bucket aside from the leftover pennies. A 2 part Byteboard interview, a technical reasoning exercise and code implementation exercise in JavaScript. Now lets try running Betterment/AuthorizationInController on the AttachmentLink example from earlier: $ rubocop app/controllers/documents/attachments_controller.rb Inspecting 1 file C Offenses: app/controllers/documents/attachments_controller.rb:3:24: C: Betterment/AuthorizationInController: Model created/updated using unsafe parameters. Keep in mind, descriptive group names go a long way in adding clarity to what dependencies that bucket relies upon. Secrets management is one of those things that is talked about quite frequently, but there seems to be little consensus on how to actually go about it. One problem was purely coding while the other involved system design on the whiteboard. If we were willing to accept tight coupling between our services, specifically in their API contracts, we'd be well-served by a tool like Pact. It is your responsibility to evaluate the accuracy, reliability, timeliness and completeness of any information available on a linked website. Each interviewer knows which competencies (e.g., software craftsmanship) to evaluate.