Sr. Backend Software Engineer

Firework; Hong Kong; On-site; HKD 600,000 - 900,000; Full time

Job summary

A leading video commerce company is seeking a skilled Sr. Backend Engineer to scale high-performance backend systems. You will collaborate closely with product managers and designers to build elegant solutions. The ideal candidate has over 4 years of Elixir experience and a strong background in SQL infrastructure. This role is hybrid, based in Hong Kong, and invites innovative thinkers eager to shape the future of commerce.

Qualifications

• 4+ years of experience with Elixir designing and building high-performance RESTful web services.
• Comfortable with change and adapting quickly in dynamic settings.
• Start-up mindset and ability to balance multiple priorities.

Responsibilities

• Design and create new APIs in the Elixir Phoenix framework.
• Debug issues across the entire stack using logging and monitoring tools.
• Review code by peers and improve engineering standards.

Skills

Elixir

SQL infrastructure

Data modeling

Redis

PostgresQL

Cassandra

Education

Bachelor’s degree in computer programming or related field

Tools

FFmpeg

GStreamer

Python

GoLang

Job description

About Firework

Join Firework – Where Innovation Meets Impact

Firework is redefining the future of commerce as an AI and video commerce company — combining cutting‑edge technology, an exclusive network of enterprise brands and retailers, and a first‑mover position to win the agentic commerce race.

We've built the world's most advanced and largest video commerce platform, trusted by global brands and leading retailers. But we're more than software — our compounding network effect grows stronger with every partner we add, bringing the energy of in‑store experiences online and transforming how businesses engage, convert, and build lasting customer relationships at scale.

Having raised over $235M to date, led by investors such as SoftBank Vision Fund 2, and operating at global scale, we offer unparalleled opportunities to solve complex challenges and drive meaningful impact in the future of connected commerce.

If you're curious, ambitious, and energized by big ideas — Firework is the place to grow, lead, and shape what comes next. Together.

Summary

Our Engineering team is growing! We’re seeking a skilled Sr. Backend Engineer to join our global team, contribute deep technical expertise and scale our high‑performance backend systems.

What you’ll be doing

• Work closely with product managers, designers, and the rest of the engineering team to design, spec, and build elegant and scalable solutions across multiple platforms
• Design and create new API's in the Elixir Phoenix framework to be used in our core products
• Writing optimized PostgresQL and Cassandra queries and creating high performance indices
• Working with in‑memory data stores, such as Redis, to improve scalability and responsiveness
• Debug issues across the entire stack using logging and monitoring tools
• Review code by your peers, offering help and insight from your experience
• Improve engineering standards, tooling, and processes
• Ensure coherence of all aspects of projects as an integrated system and uphold overall technical quality
• Strategize and develop ideas for new programs, products, or features by monitoring industry developments and trends
• Define all aspects of development from appropriate technology and workflow to coding standards

We’ll be excited if you have

• Bachelor’s degree in computer programming, computer science, or a related field; advanced degree is a plus
• 4+ years of experience with Elixir designing and building high‑performance RESTful web services serving billions of requests per day
• High‑level experience with SQL infrastructure and data modeling
• Comfortable with change: ability to demonstrate comfort with ambiguity, adapt quickly and be effective in new situations in a highly dynamic setting
• Data‑driven but also imaginative and intuitive in coming up with ideas and solutions
• Must possess a start‑up mindset: hunger to learn quickly and the ability to balance multiple priorities in a fast‑paced team environment

A BIG PLUS if you have

• Experience with GoLang or Python
• Expertise with video streaming libraries such as FFmpeg or GStreamer
• Experience working with video/audio codecs
• Experience working with live streaming encoders and WebRTC
• Experience working with AI/ML models and applications
• Experience in building large‑scale applications with Python
• Experience writing GraphQL queries and mutations

Locations

The role is hybrid and we are looking for candidates in China and Hong Kong. Candidates outside the location are encouraged to apply though must be willing to relocate.

Don’t hold back

We understand some candidates may see the above and not apply because they don’t meet all the qualifications. We encourage you to apply anyway; we often find talented candidates that fit many other opportunities we have and look for potential too, not just what you did in the past. As an equal employment opportunity employer, we are a diverse team that strives for an inclusive environment for all. We prohibit discrimination and harassment of any kind based on race, color, sex, religion, sexual orientation, national origin, age, disability, genetic information, pregnancy, or any other protected characteristic as outlined by federal, state, or local laws.