Senior Java Backend Engineer — Retention & CRM (Hybrid)

Socket.dev; Cambridge (MA); Hybrid; USD 110,000 - 120,000; Full time

Benefits offered by this job

Travel Discounts

Free lunch 2 days per week

Paid parental leave

Generous vacation

Life insurance

Job summary

KAYAK is hiring a Senior Java Software Engineer to join the Retention and CRM team in Cambridge/Concord, MA. Build scalable backend services powering Trips, price alerts, and personalized engagement for millions of users.

You will collaborate with product, marketing, design, and distributed engineers, designing complex features end-to-end and driving performance, reliability, and data integrity across the stack.

Qualifications

• 5+ years of professional software engineering experience delivering backend systems.
• Strong programming skills in Java with end-to-end feature ownership.
• Experience designing RESTful APIs and working with relational databases (MySQL or similar).
• Experience leading design and delivery of complex technical solutions and collaborating cross-functionally.

Responsibilities

• Design and deliver scalable backend services across Retention and CRM.
• Develop and improve backend services handling bulk and transactional messaging at scale.
• Architect and maintain integrations with third-party APIs and marketing platforms.
• Lead end-to-end design from scoping to deployment and monitoring.
• Mentor junior and mid-level engineers through code reviews and knowledge sharing.

Skills

Java

REST APIs

SQL

Mentoring

Cross-functional collaboration

Performance optimization

Education

Computer Science or related field

Tools

JavaScript

React

HTML

CSS

Job description

KAYAK is hiring a Senior Java Software Engineer to join the Retention and CRM team in Cambridge/Concord, MA. Build scalable backend services powering Trips, price alerts, and personalized engagement for millions of users.

You will collaborate with product, marketing, design, and distributed engineers, designing complex features end-to-end and driving performance, reliability, and data integrity across the stack.