> Markdown version of [/jobs/ext/3888408-senior-software-engineer-web-api-developer](https://www.wearedevelopers.com/jobs/ext/3888408-senior-software-engineer-web-api-developer). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md).

---

# Senior Software Engineer Web API Developer

- **Company:** Interactive Brokers LLC
- **Location:** Greenwich, CT, United States
- **Experience:** Expert
- **Contract:** Temporary contract
- **Skills:** Java (Programming Language), Application Programming Interfaces (APIs), WildFly (JBoss AS), Regression Testing, Software Engineering, PL-SQL, SQL Databases, TCP/IP, Web Services, American Standard Code for Information Interchange (ASCII), Vert.x, Backend, Information Technology, Apache Kafka, Web Api
- **Published:** October 23, 2026
- **Apply:** https://www.employmentcrossing.com/job/id-19a02567e10d04bbce6583a1b1733a4f

## About the Role

Bachelors' degree in Computer Science, or a related degree.

5 years' experience with Java

Experience with real-time and large-scale systems.

An inquisitive nature that understands the root of the problem, can maintain composure in high-stress situations with an ability to communicate with clarity, and work independently as well as within the team to provide solutions.

N

ice to Have:

Experience with TCP/IP and handling of different binary and ASCII based protocols. FIX a plus.

Previous experience designing, coding an API (REST/FIX) infrastructures a plus.

Experience with Vert.x, Wildfly, Kafka a plus.

Experience with financial markets a plus.

Experience with SQL, PL/SQL a plus.

Company Benefits & Perks

## Description

We are looking for a Senior Web API Developer to manage the software development life cycle, from planning and prioritizing to testing and release, with good knowledge and ability to communicate effectively understanding complex problems and explain their solution. The position is well-suited for an organized individual who can meet deadlines, follow written procedures, and collaborate for improvements.

You will be part of:

The Web API / Client Portal team that is responsible for the Client Portal and Web API products. As part of this team, you will help us build real-time web services around the globe that power our customer's and our own products

Your key responsibilities will be to:

Help design, develop, and maintain our Web API platform which currently provides 3rd Parties, clients and IB's customer facing applications access to highly critical real-time services required for day-to-day operations.

Work with business and internal teams adding new features and interfaces as required.

Write documentation, unit, and regression tests for new interfaces.

Write backend services and/or clients that will help expose internal services.