Skip to content
Blackbird.xyzBlackbird.xyzNew York, NY

Senior/Staff Backend Engineer

Designs, builds, and maintains core backend APIs for payments and loyalty platforms using Kotlin and RESTful services. Collaborates cross-functionally, mentors engineers, and scales systems in a fast-paced environment. Requires 5+ years experience.

180k – 220k/yr
On-site5+ YOEBackend Engineering

About the role

Responsibilities

  • Design, build, and maintain core backend APIs
  • Collaborate with product, design, and engineering peers to deliver features aligned with business goals
  • Contribute to system architecture and implement scalable, robust solutions
  • Uphold and promote backend best practices, with a focus on code quality, testing, and performance
  • Mentor junior and mid-level engineers and foster a collaborative, growth-oriented team culture
  • Participate in product and design discussions, offering backend perspectives on implementation and feasibility

Requirements

  • 5+ years of experience building and deploying backend APIs
  • Strong proficiency in Kotlin or another statically typed JVM language
  • Deep experience designing and maintaining RESTful APIs using domain-driven design principles
  • Solid understanding of SQL databases, including schema design and performance tuning
  • Strong attention to detail and commitment to delivering high-quality user experiences
  • Ability to work autonomously and make sound decisions in a fast-moving environment
  • Experience mentoring engineers and contributing positively to team culture
  • Comfortable working cross-functionally with product, design, and other stakeholders

Nice to Haves

  • Experience with the Spring framework and database abstraction layers such as Hibernate
  • Familiarity with the U.S. payments ecosystem, including debit, credit, and ACH processing
  • Exposure to DevOps practices, including AWS infrastructure and Terraform
  • Interest or experience in blockchain, especially with cryptography fundamentals
  • Experience productionizing generative AI features (e.g. retrieval-augmented generation, prompt engineering, or model integration)

Compensation

Target annual salary: $180,000-$220,000 USD (depending on work location and experience). Full time offers may include stock options, benefits (medical, dental, vision, flexible time off, 401(k)), and perks.

Skills

KotlinREST APIsSQLSpringHibernateAWSTerraformDomain-Driven DesignPaymentsBlockchain
Skylight

Senior or Staff Back End Engineer, AI Features

SkylightUnited States

Seasoned backend engineer building AI-powered features in Ruby on Rails, integrating with LLMs (OpenAI, Google, Anthropic) and owning zero-to-one product initiatives. Requires 6+ years experience shipping products end-to-end.

180k – 240k/yr
Remote6+ YOEBackend Engineering
Stellar Cyber

Senior Staff Software Engineer - Integration

Stellar CyberUnited States

Senior Staff Software Engineer owning integration domains end-to-end for an AI-driven cybersecurity SecOps platform. Architects microservices, designs APIs, mentors engineers, and leverages AI tools to accelerate development.

180k – 245k/yr
Remote8+ YOEBackend Engineering
Vapi

Member of Technical Staff, Core Backend

VapiSan Francisco, CA

Owns the StreamModule voice pipeline (VAD→STT→LLM→TTS) for real-time call agents. Consolidates BullMQ to Kafka, hardens provider abstractions, adds OTEL tracing, and eliminates Postgres SPOFs.

180k – 265k/yr
Hybrid5+ YOEBackend Engineering
Lumafield

Staff Backend Software Engineer

LumafieldSan Francisco, CA

Builds and owns scalable Python backends, REST APIs, and data pipelines for cloud platform handling X-ray/CT images. Requires 10+ years backend experience, expert Python/Django, deep AWS/PostgreSQL, with mentoring and architecture leadership.

180k – 225k/yr
On-site10+ YOEBackend Engineering
Fusion Health

Software Architect

Fusion HealthWoodbridge Township, NJ +1

Leads architectural vision and design of complex, distributed full-stack systems for healthcare software, ensuring scalability and reliability. Requires 10+ years experience with C#/.NET, Angular, cloud platforms, and influencing cross-team technical strategy.

180k – 200k/yr
Hybrid10+ YOEBackend Engineering