: Senior Software Engineer

SidelineSwap is looking for a Senior Software Engineer to design, build, and migrate back-end applications, architect performant, fault tolerant, scalable systems, and contribute to and follow engineering best practices.


About Us

SidelineSwap is the leading marketplace in the sporting goods industry. Our platform blends commerce with community to deliver a fresh marketplace experience that’s attracted more than 300k athletes, parents, coaches and entrepreneurs since we launched in 2015.


Currently, we are a small but growing team of hardworking professionals with a variety of skills sets. What we all have in common is a belief in our company’s mission: to make sports more affordable. If you’re looking to join a high-growth startup where you can make a direct impact right away, SidelineSwap may be the place for you.

We are backed by some of the best venture capital firms in consumer tech, including Global Founders Capital, and our advisors include former executives from Etsy, Staples, Amazon, and ESPN. We’re alumni of 500 Startups, MassChallenge, and the Harvard iLab.


  • Design, build, and migrate back-end applications

    • Implement synchronous and asynchronous 12 factor software applications to solve for use cases of varying complexity and risk

    • Review approaches with engineering peers and document solutions

    • Migrate existing web services to greenfield microservices applications

    • Work the the team to make recommendations on how to improve existing systems

  • Architect performant, fault tolerant, scalable systems

    • Use modern design patterns to create a “shared-nothing” architecture

    • Engineer solutions that meet transactional demand now and scale for the future.

  • Contribute to and follow engineering best practices

    • Contribute to and adhere to company standard design patterns and best practices.

    • Perform static code analysis to avoid high complexity implementations and security vulnerabilities

    • Implement unit tests and functional tests where applicable.

Competencies for this role:

  • Strong Programmer. Understands how to build and support critical transactional systems. Experienced in building order, payments, and fraud processing systems. Experience building RESTful services, working with message queues, and batch processing applications. Experience interacting with RDBMS and NoSQL databases. Skilled *nix operator.

  • Systems Architect. Knowledgeable about modern systems architecture components including networking, microservices, messaging systems,  and distributed data processing systems. Knowledge of service-oriented and microservices architectures.

  • AWS User. Has experience standing up cloud compute instances and deploying applications to Amazon Web Services

  • Team Player. Works well with a team, selfless, always ready to help others.

  • Self Motivated. Able to prioritize and execute on initiatives autonomously if needed.


  • 4+ years of experience working with Java (1.7+) or Kotlin and frameworks like Spring Web MVC, Spring Boot, Spring Flux and reactive programming.

  • Experience with the AWS ecosystem

  • Experience with Ruby on Rails , Apache Hadoop, Apache Spark is a plus

  • May require a bachelor degree in Computer science

  • Must plan to work a majority of time on-site at our new office in Charlestown, only a couple T-stops away from downtown Boston.