Senior Full Stack Engineer (Python & Flutter)

Note: This role is on-site in Bali.

About Slash

Slash is an Innovative Digital Solutions Build Studio and Recruitment Consultant for IT teams. Our recruitment consultants specialize in building remote or hybrid autonomous teams to help innovators develop software & digital products, and launch hi-tech startups. We’ve cracked the code in helping our highly-skilled, global technology talent community connect with leading companies based on our experience in building and investing in our own startups and commercializing them through joint ventures in ASEAN and Europe. 

Slash has headquarters in Singapore and community-oriented R&D hubs in Phnom Penh, Yerevan, Jakarta, Bandung, Yogyakarta and Bali, and is building its hubs in the Philippines.

We are looking for a highly capable Senior Full Stack Engineer for one of our long term clients in Bali, who are working on a wellness product. The product is an emotional insight tool that helps users understand how they feel, why they feel it, and what it means over time. The product is live and currently being market-tested.

Recent achievements include significantly enhancing product speed and quality to improve user experience, streamlining documentation and handover processes to ensure smoother team collaboration, and successfully delivering the project milestone for public release, positioning it for broader market adoption.

As Senior Full Stack Engineer, you will play a pivotal role in building next phase of features, scalability, and user experience, ensuring it continues to evolve as a best-in-class product.

• Lead the end-to-end development of applications across front-end (Flutter) and back-end (Python/FastAPI).
• Architect, design, and implement scalable systems and APIs, ensuring reliability and performance.
• Collaborate with hardware/firmware engineers for integration, while focusing primarily on software layers.
• Guide decision-making around technical priorities, trade-offs, and system architecture.
• Mentor team members and provide leadership in project execution.
• Own and optimize the deployment pipeline using Docker and Google Cloud Platform services (Cloud Storage, Cloud Run, Cloud Tasks).
• Manage WebSocket streaming, background processing, and Bluetooth communication within mobile applications.
• Support occasional website updates (HTML, CSS tweaks) for the marketing site.
• Lead and scope technical ownership based on project needs:
• Partner with Hardware/Firmware Engineer for hardware/firmware updates.
• Handle UI/App updates (both front-end and back-end) independently or in collaboration.
• Drive backend optimizations and new feature development with a focus on scalability and performance.

• Balanced Full Stack Development expertise (50/50 front-end and back-end).
• Strong Mobile Development experience with Flutter (Bluetooth APIs, background processing).
• Proficiency in Backend Development with Python (FastAPI).
• Experience with Cloud & Containerization (Docker, Google Cloud Platform services).
• Ability to work independently, communicate clearly, and translate requirements into scalable solutions.
• Familiarity with APIs such as OpenAI, Deepgram, Hume AI, or other transcription/audio services (nice to have).
• Understanding of audio codecs (OPUS, PCM/WAV), bandwidth optimization, and audio frame handling (nice to have).
• Experience with basic web coding (HTML, CSS) for quick marketing site tweaks (nice to have).
• Proven experience as a Tech Lead — not just an individual contributor.
• Track record of leading technical projects, making architectural decisions, and mentoring engineers.
• Prior experience in startup or fast-paced environments is a strong plus.
• Deep expertise in AI/ML, DevOps, hardware, or firmware is not required (covered by dedicated specialists).

Ready to shape the future of emotional insight?

If you’re a Full Stack Engineer who thrives on technical challenges, loves building impactful products, and wants to play a pivotal role in bringing our product to its next stage of growth, we’d love to hear from you!

For more information, visit us at www.slash.co