In order to do this, we built out a fake http client that allows us to configure network responses for given requests. "trust-root chaining"). Fidel Severino: While working, I would take any available time for courses on websites like Codecademy and Team Treehouse. For Java apps and libraries we run integration and unit tests by default as well asPMDas part of our static code analysis. How is their IT department for roles like Director or VP? Sometimes there are a few layers of indirection between a service and a Betterment customer, and it takes a bit of creativity to understand what aspects of the service directly affects them. One Massive Monte Carlo, One Very Efficient Solution We optimized our portfolio management algorithms in six hours for less than $500. After this process, I am a fan of Betterment. In certain scenarios, its undesirable to buy or to sell a specific fund because of tax consequences. Lets run it through the gauntlet to show how it works and how it solves for all our requirements. As demonstrated, Rails provides some methods that mark content as safe without escaping it for us. If our acceptance criteria change, because everything is written in code, adding a new job involves a simple code change and a few tests, and thats it. For the screen for changing your name and byline, we can build a robot to interact with the screen that looks something like this: By using this pattern, we are able to reuse test code pertaining to this screen across many tests. Interviews at Betterment Experience Positive 56% Negative 28% Neutral 17% Getting an Interview Applied online 81% Recruiter 6% Employee Referral 6% Difficulty 2.9 Average Hard Average Easy Interviews for Top Jobs at Betterment Software Engineer (18) Customer Experience Associate (8) Product Designer (4) Product Manager (4) Unfortunately, if it were so simple we wouldnt be here, several paragraphs into a blog post on the topic. Weve achieved our goalweve allowed for all the functionality of integration without the threats of actual integration. 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. The interviews varied between programming questions, system design and behavioral. Weve pushed the aforementioned nuisance and complexity into our data pipeline (ETL) process and are able to synthesize atomic and summary metrics in a format that is more intuitive for our business users. The Problem Proportional allocation comes up often throughout our codebase, but its easiest to explain using a fictional example: Suppose your paychecks are $1000 each, and you always allocate them to your different savings accounts as follows: College savings fund: $310 Buy a car fund: $350 Buy a house fund: $200 Safety net: $140 Now suppose youre an awesome employee and received a bonus of $1234.56. Julia also has a very rich type system where researchers can build prototypes without type declarations, and then later refactoring the code where needed with type declarations for dispatch or clarity. are kept secure at every stage of the software development lifecycle. To do good data work today, you need to use a system that is reproducible, versionable, scalable, and open. Took about an hour or two total. I applied online. Since then, the team has met several times to gather feedback and implement tweaks, but the broad strokes have remained unchanged. Too often, the events involved forced networking and stodgy PowerPoint presentations, with takeaways amounting to little more than a free glass of wine. Felt as if it was waste of my valuable time, not just with the interviews but for case study as well. Perhaps it is time to dedicate a sprint or two to understanding whats causing degradation of service. Ill discuss these more below. Those three principles are: Authorization through Impossibility Authorization through Navigability Authorization through Application Boundaries This post will explore the first two principles and provide examples of common patterns that can lead to vulnerabilities as well as guidance for how to fix them. The second member is client_analytics. 16.0availableacrossallstores. There needs to be a way to set up a new project. If we dont escape content properly, we could open ourselves and our customers up to security risks. We think that our Web app will be just as pleasant to use, and we can more quickly enhance and build new features going forward. Finally, flutter_driver is not built to run a suite of tests or to run easily in CI. In the near term, look for smaller pieces of the analytical workflow which would benefit especially from the efficiencies of reproducible, programmatic analysis and reporting. Use your answer to highlight some of the most important skills for a junior software engineer, along with examples of how you've used those skills in the past. Is the authenticated user authorized to operate on the resource in accordance with Rule #1? If we find a match, we return it, if we don't then we throw a helpful exception to guide the developer on how to fix the issue. After that there was a first round interviews with 2 software engineers and 1 manager totaling about 2.5 hours. What parameters is the authenticated user submitting? We wanted to have a test harness that we could use to set up the app under test and the world that the app would run in, however we knew this configuration code would be mildly complicated and something that would be in flux. Simply put, weve asserted that the sum of the balances of every fund in Joes taxable account must remain at $11,000. For example, a task computing all of a prior days activity executed at midnight would be inaccurate if Redshift were missing data from DMS at midnight due to lag. Each variable represents the expected value of holding a particular fund in a particular account. 12.00% 3.200lbsofthyme. When reviewing code, I look for adherence to coding standards, code efficiency, readability, and maintainability. Modeling and implementing our portfolio management algorithms using linear programming was not easy, but it ultimately resulted in the simplest possible system needed to reliably pursue optimal after-tax returns. There are a number of subjects that need to be covered in order to ensure you are ready for back-to-back questions on algorithms, data structures, design, optimization and honestly just an ever . 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. We then pivoted to investigating Flutters newer replacement for flutter_driver: integation_test. And our platform needed to grow along with it. Technical interviewsSeries of pair-programming challenges, 2. While possible to run in CI, it would be incredibly costly to run on each commit since the tests need to run on actual devices. She and I both live in NYC now, and we see each other regularly at speaking engagements and chat over email about networking and inclusion. Very pleasant and friendly experience. I dragged my chair ten feet across the office and began my new life as the engineering lead of Betterments nascent data teammy new mates included two talented data analysts, a data warehousing engineer and a marketing analyst, also the product owner. 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. Those bootcamps changed all of our lives! Ideally, the same tools you build to understand your data when youre at 10 employees should scale and evolve through your IPO. We did it! Our process was heavily test-driven, during which product engineering reimplemented many of the R tests in JavaScript, understood the R codes intent, and ported the code while modifying for client-side performance wins. Its all grounded in developing the best solutions for our customers and helping them achieve financial wellness. Also, we are providing the constraints as tuple of dictionaries. New York City Metropolitan Area. Step 2: 2-3 hour pair programming technical round in an IDE. They can define what is called an aspirational SLO - basically an SLO for an important component in their system - to start collecting data over time. Before building anything ourselves, we did some research to figure out what the community had already done. 2 Technical interviews, followed by an AMA style lunch and then behavioral interviews for the rest of the day. Then there was a second round interview with another software engineer, a technical project manager and the director of engineering. What interested you in this position? We needed a workflow with less of a bottleneck, but allowing every developer access to all the secrets across the organization wasnotan acceptable answer. So, your college savings fund would get: (310/1000)*1234.56 = 382.7136 We can do the same for your other three accounts, but you may have noticed a problem. But I really liked how "organic" these problems were since I got a sense of the actual challenges I would be facing as well as the tools and practices used by the team. Other Testing Recommendations Consider shared examples for last-mile regression coverage and repeated patterns. A PR build failed. I found Chethan to be highly proactive, organised and considerate as a teammate. There are also feasibility limits. 4.5 hr virutal onsite - three 45 min tech interviews with 15 - 30 min breaks. If youre the first convert, absolutism is probably not the right approach. From 1 to N: Distributed Data Processing with Airflow Betterment has built a highly available data processing platform to power new product features and backend processing needs using Airflow. By harnessing the power of Amazon Web Services (specifically EC2 and S3) and a cloud-based message queue called IronMQ we reduced that testing time to just six hoursand for a total cost of less than $500. We also have a few heftier integration tests to confirm our expectations. Ask Carmen Reinhart and Kenneth Rogoff, two Harvard economists who published an influential paper on sovereign debt and economic growth, only to find out that the results rested in part on the accidental omission of five cells from an average. So if you can encrypt them safely, you can ship your secrets with your code and have a single change management workflow. However, in modern versions of Rails, that has changed. The need for new elements in our views is not going to simply vanish because we rebranded, so this makes us more prepared for the future. One of our primary aims in building this platform was to increase developer velocity, so we needed to eliminate any friction from commit to deploy. CSS (the appearance): In this example, we use it to set things like the color, alignment and the border. While we want to iterate rapidly, we strive to never compromise the security of our customers nor the correctness of our code. This blog post discusses the different responsibilities of these types of specs, and other related high level guidelines for specs. Dealing With the Uncertainty of Legacy Code To complete our portfolio optimization, we had to tackle a lot of legacy code. Working with our product team, we determined that the minimum amount of change to consider a page rebranded was adoption of the new header, footer, colors, and fonts. Regardless, given that it has the same problems that flutter_driver does, we decided not to pursue integration_test as our framework. We dont want to terminate workers while theyre finishing something up and instead want them to terminate after the work is done (not accepting new work in the interim). We wrote tests around the methods in question. Byteboard. The simulated data allows us to generate novel potential outcomes, like market crashes bigger than previous ones, and generally, futures different than the past. Straightforward tests are easy to write, read, and maintain. If we used a research-first approach to build RetireGuide, the result could have been a planning tool that was mathematically sound but hard for our customers to use. These guidelines constituted our opted out experienceviews that would receive this lightweight reskin immediately but not the full rebrand treatment. The process took 1 week. 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. But data alone is not enoughwe needed the right storytellers. Interview was 30 mins. I thought my 5 year was going to finally show something but it did not. Engineering at Betterment: Do You Have to Be a Financial Expert? The take home and both onsite interview questions were not arbitrary but very practical and relevant to what I'd actually be working on. 2) Small take home problem, mostly about correctly reading requirements and providing an implementation. With spreadsheet software in every cubicle, analytical horsepower was commoditized and Excel jockeys were crowned as the arbiters of truth in business. Ive inquired about pay but its gotten nowhere. We wrote a controller-level hook to update the variant and render the new layout files, reskinning thepackage. Build extra time into project estimates Legacy code can also be tricky when it comes to project estimates. In Betterments mobile apps, this means including trustworthy but convenient local authentication options for resuming active login sessions. Our systems are generally stable, and feature development is paramount to business success. This made the problem provably solvable and quick to computeon the order of milliseconds per customer. I get it, maybe you only want to hire people who know Ruby and that's fine, however you shouldn't waste other people's time. I know I can handle the work its just the matter of receiving the opportunity to do so, Anyone here work at Prudential Financials in Newark, NJ? It also doesnt assist users in acting on the results it gives. A Redis-based queue will still introduce DB pressure if its jobs execute anything involving ActiveRecord models, and solutions must exist to throttle or rate limit these jobs. Onsite they give you a mock project where you have to complete the requirements. Each set of strategies was confronted with both bootstrapped historical data and novel simulated data. All return examples and return figures mentioned above are for illustrative purposes only. In person pair programming was in Ruby only. First things firstdefining our view of the problem space. Colorado: $175,000 - $190,000. To implement our component system, we created our internal gem, Style Closet. At a high level, the Coach CLI generates a lot of yaml files that are used in all sorts of places to help manage operational complexity and cloud resources for consumer-facing web-apps. As a result, we had to build features into sopsorific to allow vendor provided secrets that didnt meet the sopsorific standards by default to be accepted by sopsorifics checks. In order to fulfill two of our main requirements: being able to run as part of our normal test suite in CI and having a familiar API, we knew wed need to build our framework on top of flutters existing screen test framework. 32.0availableacrossallstores. 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. As a computer science major, school has taught me how to code in Java, and maybe some of the theoretical stuff that Ive had drilled into my head will come in handy at some point in my life. Vim! 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. Alternatively, if you want to actually pass complex objects out, youll have to ensure Julia holds a reference to the objects beyond the life of the function, in order to keep them from being garbage collected. I identified the most visible spots where we address a user and changed them, but for less visible changes I took this new map and delegated cross-squad ownership of each usage. This becomes even more dangerous if the Documents table uses sequential ids, as that would make it easy for an attacker to start combing through the entire table. Over time, a handful of these teams formed deviating opinions on what kind of acceptance criteria they had for CI. For this reason, if you do write characterization tests, we recommend not going too far with them. Before working at Betterment, I didnt think finance was relevant to me. For our Ruby on Rails apps, that looks like this: sopsorific run 'bundle exec rails c' What did we learn? Granted, having exactly-once semantics would be preferable, but if we cannot be sure that our jobs run at least once, then we must ask ourselves: how would we know if something didnt run at all? I was also invited back the following week to speak with another product person and the CTO. We solve problems from different angles. SLOs in code Now that we have our metrics flowing, our engineers can define SLOs. Read our blog post to find out more. Luckily, we can use Rubys powerful metaprogramming abilities to abstract all that awaycreating a declarative way to wrap an arbitrary Julia function which results in a familiar and easy-to-use interface for Ruby developers. There was the feature work stream which involved: Storing the users new name information. We could have attempted to construct a procedural-style heuristic solution to this, but the complexity of the problem led us to believe this approach would be hard to implement and challenging to maintain. Finally, we sort our buckets in descending remainder order (because the buckets with the highest remainders are most deserving of extra pennies) and allocate the leftover pennies we have in this order. The CLI handles notifications, artifact generation, and deployment triggers. Phone call + take home test prior to onsite. While we love the concern that our engineers show toward solving these problems, these deviations became problematic for applications of the same runtime that should abide by the same set of rules; for example, all Ruby apps should runRSpecandRubocop, not just some of them. This gives us the confidence that all our code is configured properly, all our dependencies are provided, our navigation works, and the user can tap on whatever and see what they'd expect to see. In other words, the following test file will always exit successfully, despite the fact that there are obvious issues with how its set up. We also maintain two other dashboards in our cloud monitoring service, DataDog. This was about 3 hours, 2 - 1 hour paired programming exercises with members of the team, and a 30 minute conversation/soft skills interview with the hiring manager. 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. Sri Lanka. Stability through Randomness We only recently enabled test randomization and as a result found that some of our tests were failing. The process took 3 weeks. Next, we settled on an algorithm which pays out buckets fairly, and guarantees that the total payments exactly sum to the desired payout. The SLO is the target percentage, 99.9%. Also note, do not get your hopes up if you get a personal call from your recruiter after the final interview. Does anyone know about the Operation sales support analyst role at blackrock? During our testing, we ran over 200,000 simulations of 12 daily level returns of our 12 asset classes for 20 year's worth of returns. A nice property that weve observed at Betterment, and that might apply to you as well, is that the number of jobs tends to scale proportionally with the number of customers and accounts. There was no hint of arrogance or a lack of candor from anyone. Next, we find the leftover pennies by taking the inflow minus the total of the integer quotients, which is 123456(38271 + 43209 + 24691 + 17283) = 2. In this example, we are trying to maximize the number of pounds of ingredients he can buy because that will result in the most soup. Having a tool to protect ourselves from ourselves is vital to our workflow. 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. They were very rude. These are REALLY basic things that you can do if you have some rails experience, but if its your first time looking at it, you're SOL, and your interviewers will at best try to nudge you to the right documentation page to read mid interview. Several times we ran into corner cases around old users, test users, and other anomalous data that caused false positive failures in our characterization tests. Well fake the integration by using Sinatra to build a rack app that quacks like the real thing. After spirited internal discussions we landed on a simple principle: We should provide candidates the most natural setting possible to demonstrate their abilities. The first of these issues was that the cop allowed usage ofrawandhtmlsafewhen the usages were wrapped insafejoin. IMHO, Betterment hiring process is best in the business. This new flexible set of asset allocations significantly affects our current trading processes. It was just a moment in time that came and went: In the New World we wanted to proclaim loudly (or as loudly as you can proclaim in a Slack message) that the pull request was successful in CI: Tada! I came away from the in-person meetings with a strong sense that this would be both a great learning opportunity and an excellent group of people to work with. For this we can use a mathematical programming solver. Free interview details posted anonymously by Betterment interview candidates. By only using the server as a JSON API, the frontend needed to know exactly what to do with that JSON. We reach our SLO goal if, during a 30 day period, 99.9% of all requests completed with one of those status codes and within that range of latency. With a solid plan for gathering user input, we pivoted to the bigger question: Where should we use a customers preferred first name? Ship It Our first run of this new process took place in November 2015. The last straw for using whiteboards came from feedback provided by Betterments Women in Technology group. While S3 is great for production, its a little difficult to work with in development and testing where we prefer to use the local filesystem. It looks just like our ideal spec from before: We leverage all the power of WebMock and Sinatra through our conventions and the teeniest configuration to provide all the same functionality as before, but we can write cleaner tests, we get the ability to use these fakes in local development instead of the real servicesand we can enable a real service integration without missing a beat. The first round of "in person" interviews. Maybe we need to reevaluate the metrics were collecting, or perhaps were okay with setting a lower target goal because there are other targets that will be more important to our customers. When we first saw this project on the horizon, we realized it would end up requiring a substantial refactor of our web app. It's not quite the interactive experience of the Datadog UI, but it's fairly straightforward to fiddle in the UI and then extract the resulting configuration and add it to our config file. I interviewed at Betterment. Quite a bit more complicated, because each backend framework provides its own set of trade-offs and guarantees, many of which will have far-reaching implications in our codebase. 1) Phone screen about the company Alternatively, stick to only interviewing candidates who know Ruby. The last straw for using whiteboards came from feedback provided by Betterments Women in Technology group. The process took 3 weeks. So even if your queue lives in an entirely separate datastore, it can be effectively coupled to your DB's IOPS and CPU limitations. Simple. When controllers are thin and models are tested heavily, there should be no need to duplicate business logic test cases from a model spec in a request spec. All teams at Betterment are responsible for teasing apart complex financial concepts and then presenting them in a coherent manner, enabling our customers to make informed financial decisions. How is their IT department for roles like Director or VP? And we think we made it a little easier for them (and us) to do just that. Redis-based queues, for example, can only be as durable (the D in ACID) as the underlying datastore, and most Redis deployments intentionally trade-off some durability for speed and availability. While the nascency of Julia as a language means that the community and ecosystem is much smaller than those of other languages, we found that the code and community oversamples on the type of libraries that we care about. There are plenty of other features that weve built that havent made it into the delayed gem quite yet. When theres no more work to be had, the worker shuts itself down. Lets say it is. What are "end-to-end-ish" tests? As of July 2016, all full-stack, mobile, and site-reliability engineering roles have adopted this new approach. As a result, in addition to learning how well a candidate can write code, we learn how well they collaborate. But the point is that jobs are never simply dropped, or silently deleted, or lost to the cyber-aether, at any point, from the moment we enqueue them to their eventual resolution. 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. If you don't know Ruby + rails, don't bother since it's the only language you're allowed to work with. Those come to life in four major principles, which guide how we engage with the problem space for our shift to a service-oriented architecture: We use HTTP & REST to communicate with collaborator services We define the boundaries and limit the testing of integrations with contract tests We don't share code across service boundaries Engineers must remain nimble and building features must remain enjoyable. We built an additional package into our monorepo whose sole purpose was to expose an API for our Ruby application, as well as compile that exposed code into a C shared library. I didn't connect too well with one of the managers in the final round and saw the rejection coming. 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 is because both of the cops keep a little bit of state to ensure they have the appropriate context necessary when analyzing potentially unsafe function calls. We like to extract standard assertions such as ones relating to authentication into shared examples. The process took 2 days. Ability to keep pace with changes to the mathematical model, e.g., adding, removing, and changing the constraints and the objective function must be quick and painless. This is why we adoptedDockerto run a production-like Airflow cluster from the ground up on our development machines. Most teams need to deploy to multiple environments: production, staging, feature branches, sales demos, etc. The benefit we found in flutter_driver was that we could run it in our production-like environment against preset test users. Before we built TCP, Betterment customers had each account managed as a separate, standalone portfolio. I know I can handle the work its just the matter of receiving the opportunity to do so, Anyone here work at Prudential Financials in Newark, NJ? 15.00% 2.000lbsofgarlic. Using Targeted Universalism To Build Inclusive Features The best products are inclusive at every stage of the design and engineering process. Its all about the customer This is where the philosophy of defining and keeping track of SLOs comes into play. 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. Questions were in JavaScript, ruby on rails, and React having to implement specific features into a pre developed app. What is Secrets Management? Also, the flutter_driver API worked differently than the screen testing API and was generally more difficult to use. Betterment is a leading, technology-driven financial services company that offers investing and retirement solutions for retail investors and investment advisors as well as financial wellness solutions, including a 401(k) for small and medium-sized businesses. Benefits of measuring the right things, and staying on target The goal of an SLO based approach to engineering is to provide data points with which to have a reasonable conversation about priorities (a point that Alex Hidalgo drives home in his book Implementing Service Level Objectives). What our Engineers Needed For pull requests, developers would commit code and push it up to GitHub and then eventually they would receive a Slack message that said BAD for every test suite that failed, or GOOD if everything passed, or nothing at all in the case of a Jenkins agent getting stuck and hanging forever. (Essentially, it means keeping our on-call engineers happy.) Whos allowed to do what? This manual testing was tedious and time consuming for engineers, whose time is expensive. How is pay, wlb & work culture. If youre significantly exercising behavior not in the layer youre writing a test for, you might be putting the test in the wrong place. Discussion Finally, weve added an Ask-Me-Anything (AMA) sessionanother idea provided by our Women in Technology group. I also pay attention to the use of appropriate design patterns and algorithms .