Software Engineer, Platform Team

About the role

We are looking for engineers who want to own problems end to end, and who care about making investment portfolio management scalable, correct and reliable. You have a high degree of personal responsibility and enjoy working across the entire application all the way from requirements through implementation and deployment. You will own the full lifecycle of critical platform features, tracing requirements from discovery through design, implementation, testing, and on call responsibility. This role gives you direct ownership of the mechanisms that ensure portfolio calculations stay consistent when the system is under load. You will be trusted to make technical decisions that materially impact how our services behave in production. You will collaborate closely with product and domain experts to translate ambiguous business needs into concrete, reliable system behavior. You will be expected to mentor more junior engineers by demonstrating strong engineering habits and clear communication.

Key facts

What you'll do

Investigate and clarify ambiguous requirements by asking targeted questions and translating them into precise technical specifications for complex portfolio operations. Design and implement services that handle real time market events, corporate actions, and user actions while preserving strict event ordering and data integrity. Analyze production incidents and edge cases, then build safeguards and observability to prevent recurrence across large portfolios. Collaborate with product management to scope solutions that balance correctness, performance, and delivery timelines under realistic constraints. Break down complex domain logic into testable components that are straightforward for other engineers to understand and extend. Partner with the support team during rotation shifts so you see real user behavior and operational pain points directly. Evaluate and adopt new tools or libraries when they meaningfully reduce operational risk or development effort in this domain. Communicate technical tradeoffs clearly to both engineering and non engineering stakeholders through documentation and discussions. Mentor teammates by writing clean code, providing thoughtful code reviews, and sharing knowledge gained from on call incidents. Contribute to architectural decisions that allow the system to scale while remaining understandable and maintainable over time.

Requirements

2-6+ years of experience building production web applications in roles where you shipped features that affected real users. Demonstrated ability to reason about systems with complex domain logic and concurrent, order-sensitive state where timing matters. Strong understanding of computing fundamentals, particularly multiprocessing and multithreading considerations and how they affect data consistency. Proficiency in Ruby on Rails or similar MVC frameworks with experience rendering views, managing forms, and working with server side templates. Strong SQL skills including writing complex multi table queries, understanding query plans, and reasoning about data integrity under concurrent writes. 1+ years of daily experience working in a Linux environment with strong familiarity with common command line utilities and Unix process management, and comfort with bash scripting. Experience managing background job processing and at least one message driven architecture for reliable event handling. Track record of writing and maintaining tests that give confidence when changing behavior in critical financial calculations. Comfort operating in cloud environments where infrastructure as code practices and containerization are used to deploy services. Willingness to learn the specifics of financial industry terminology and business workflows quickly without prior domain experience.

Nice to have

Experience building or operating systems that handle financial transactions or reconcile balances at scale. Deep familiarity with portfolio accounting, rebalancing mechanics, and related regulatory concepts. Contributions to open source projects that demonstrate sustained engineering impact and maintenance. Published work or public talks that show thought leadership in distributed systems or correctness engineering.

Practical notes

We prefer candidates who are willing to work in a hybrid environment. Candidates in the Boston area should expect to work in office 2 days per week for the first 6 months and optionally remote thereafter. Candidates outside the Boston area should expect to travel to Boston for 1 week at a time several times in the first six months and 3x per year thereafter. Smartleaf is unable to provide visa sponsorship now or in the future. This ineligibility applies to all employment related visas.