Careers — Arthur Ventures
Sr. Software Engineer – API Team at Avalara
Seattle, WA, US

The successful candidate will be a well-rounded software development engineer with strong experience in C# and database design, passionate about developing useful software that will be deployed around the world. 

API team engineers write their own tests and develop their own requirements with assistance from business analysts.  Team members are expected to carefully balance tradeoffs such as usability, security, performance, maintainability, comments, code reviews, automated deployment, and ongoing analysis and improvement.

Avalara’s API team works in an agile/scrum model with low overhead and each employee is expected to self-select their work items in conjunction with their colleagues.  All projects are built using pull requests and each PR must demonstrate that it passes both code review and integration tests before it can be merged.

Job Duties

  • Write maintainable, clean code with lots of comments and documentation.
  • Only optimize for performance after the simple approach is tried and performance metrics demonstrate an opportunity for improvement.
  • Be inquisitive and learn about the world of accounting, tax compliance, audits, and business practices whenever the opportunity presents itself.
  • Implement both SQL-based and NoSQL-based data storage solutions in the appropriate contexts
  • Think through your API from the perspective of an attacker and demonstrate every way something could go wrong.
  • Sketch out your own test cases in the planning phase.
  • Write integration tests and unit tests for every pull request.
  • Read and understand requirements, and search out ways to “go big” – to solve the underlying problems.
  • Partner well with team members for code reviews and test plans.
  • Describe your projects with patch notes and present your algorithms in our security/stability meetings each month.
  • Work with the developer relations team to ensure that each feature is useful for, and simple enough to be understood by, the target audience.
  • Write fantastic C# code.
  • Design solid data models and make effective use of database technology.
  • Constantly seek out ways to do a better job and improve automation


  • Computer science degree or equivalent experience
  • Strong written and verbal communication skills
  • 2+ years professional experience with at least one NoSQL / document data store such as MongoDB, DynamoDB, or other equivalents
  • Ability to discuss software development issues in a casual and friendly manner, making code accessible to everyone
  • 2+ years of open source software experience working with communities via GitHub or equivalent
  • A desire to write great documentation and see your product be the best in the business
  • Demonstrable mastery of at least one language (C#, Java, C++, JavaScript)

Preferred Qualifications

  • Development experience in multiple programming languages
  • Deployment automation scripting experience
  • Familiar with SQL Server / other relational databases
  • Familiar with MongoDB / DynamoDB / other NoSQL databases or document / column stores
  • Familiar with OpenAPI / Swagger / Swashbuckle
  • Familiar with AvaTax

About Avalara

Avalara helps businesses of all sizes achieve compliance with transaction taxes, including sales and use, VAT, excise, communications, and other tax types. The company delivers comprehensive, automated, cloud-based solutions designed to be fast, accurate, and easy to use. The Avalara Compliance Cloud® platform helps customers manage complicated and burdensome tax compliance obligations imposed by state, local, and other taxing authorities throughout the world.

Avalara offers more than 600 pre-built connectors into leading accounting, ERP, ecommerce and other business applications, making the integration of tax and compliance solutions easy for customers. Each year, the company processes billions of indirect tax transactions for customers and users, files more than a million tax returns, and manages millions of tax exemption certificates and other compliance documents.

Headquartered in Seattle, Avalara has offices across the U.S. and overseas in the U.K., Belgium, Brazil, and India. 

Avalara is an Equal Opportunity Employer. All qualified candidates will receive consideration for employment without regard to race, color, creed, religion, age, gender, national orientation, disability, sexual orientation, US Veteran status, or any other factor protected by law.